diff --git a/.editorconfig b/.editorconfig
index 7057494e882..c0cb766f2e0 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -24,7 +24,6 @@ ktlint_standard_backing-property-naming = disabled
 ktlint_standard_blank-line-before-declaration = disabled
 ktlint_standard_blank-line-between-when-conditions = disabled
 ktlint_standard_chain-wrapping = disabled
-ktlint_standard_comment-wrapping = disabled
 ktlint_standard_function-naming = disabled
 ktlint_standard_function-signature = disabled
 ktlint_standard_indent = disabled
@@ -47,8 +46,6 @@ ktlint_standard_statement-wrapping = disabled
 ktlint_standard_string-template-indent = disabled
 ktlint_standard_trailing-comma-on-call-site = disabled
 ktlint_standard_trailing-comma-on-declaration-site = disabled
-ktlint_standard_value-argument-comment = disabled
-ktlint_standard_value-parameter-comment = disabled
 ktlint_standard_wrapping = disabled
 
 # enable some experimental Ktlint rules
diff --git a/CHANGELOG.md b/CHANGELOG.md
index efa32644a81..05c02728223 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -36,7 +36,7 @@ you map places that are not shops - like hotels, hospitals, schools and so forth
 
 ### Other
 
-- Fix a (shokingly common) crash (#5498)
+- Fix a (shockingly common) crash (#5498)
 - Fix issues with doing edits while data is being downloaded (#4258)
 - Add some interesting links as achievement rewards (#5466)
 - Translation to Amharic has been disabled, it was not maintained for over a year
diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index 35a7326ba0d..54634c657e7 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -154,6 +154,11 @@ dependencies {
     // scheduling background jobs
     implementation("androidx.work:work-runtime-ktx:2.9.0")
 
+    // HTTP Client
+    implementation("io.ktor:ktor-client-core:2.3.8")
+    implementation("io.ktor:ktor-client-cio:2.3.8")
+    testImplementation("io.ktor:ktor-client-mock:2.3.8")
+
     // finding in which country we are for country-specific logic
     implementation("de.westnordost:countryboundaries:2.1")
     // finding a name for a feature without a name tag
diff --git a/app/proguard-rules.pro b/app/proguard-rules.pro
index 8371cb97fd0..084bd0320fd 100644
--- a/app/proguard-rules.pro
+++ b/app/proguard-rules.pro
@@ -5,7 +5,6 @@
 # let's just keep everything
 -keep class com.mapzen.tangram.** { *; }
 -keep class com.mapzen.tangram.* { *; }
-
 # tangram end --------------------------------------------------------------------------------------
 
 # Lifecycle
@@ -47,6 +46,9 @@
     kotlinx.serialization.KSerializer serializer(...);
 }
 
+# ktor client, see https://youtrack.jetbrains.com/issue/KTOR-5528
+-dontwarn org.slf4j.impl.StaticLoggerBinder
+
 # Change here com.yourcompany.yourpackage
 -keep,includedescriptorclasses class de.westnordost.streetcomplete.**$$serializer { *; }
 -keepclassmembers class de.westnordost.streetcomplete.** {
diff --git a/app/src/androidTest/java/de/westnordost/streetcomplete/data/osm/edits/EditElementsDaoTest.kt b/app/src/androidTest/java/de/westnordost/streetcomplete/data/osm/edits/EditElementsDaoTest.kt
index 35670e1b656..6322c47e495 100644
--- a/app/src/androidTest/java/de/westnordost/streetcomplete/data/osm/edits/EditElementsDaoTest.kt
+++ b/app/src/androidTest/java/de/westnordost/streetcomplete/data/osm/edits/EditElementsDaoTest.kt
@@ -31,8 +31,8 @@ class EditElementsDaoTest : ApplicationDbTestCase() {
         ))
 
         dao.put(7, listOf(
-            ElementKey(ElementType.NODE, 0),  // referring to same element
-            ElementKey(ElementType.WAY, 1),  // but also another
+            ElementKey(ElementType.NODE, 0), // referring to same element
+            ElementKey(ElementType.WAY, 1), // but also another
         ))
 
         dao.put(3, listOf(
diff --git a/app/src/main/java/de/westnordost/streetcomplete/ApplicationModule.kt b/app/src/main/java/de/westnordost/streetcomplete/ApplicationModule.kt
index 4f2132de563..03904a97144 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/ApplicationModule.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/ApplicationModule.kt
@@ -5,6 +5,9 @@ import android.content.res.Resources
 import de.westnordost.streetcomplete.util.CrashReportExceptionHandler
 import de.westnordost.streetcomplete.util.SoundFx
 import de.westnordost.streetcomplete.util.logs.DatabaseLogger
+import io.ktor.client.HttpClient
+import io.ktor.client.plugins.defaultRequest
+import io.ktor.http.userAgent
 import org.koin.android.ext.koin.androidContext
 import org.koin.dsl.module
 
@@ -15,4 +18,9 @@ val appModule = module {
     single { CrashReportExceptionHandler(androidContext(), get(), get(), "helium@vivaldi.net", "crashreport.txt") }
     single { DatabaseLogger(get()) }
     single { SoundFx(androidContext()) }
+    single { HttpClient {
+        defaultRequest {
+            userAgent(ApplicationConstants.USER_AGENT)
+        }
+    } }
 }
diff --git a/app/src/main/java/de/westnordost/streetcomplete/StreetCompleteApplication.kt b/app/src/main/java/de/westnordost/streetcomplete/StreetCompleteApplication.kt
index 79a142c97a4..e35ef583112 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/StreetCompleteApplication.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/StreetCompleteApplication.kt
@@ -150,7 +150,7 @@ class StreetCompleteApplication : Application() {
             preloader.preload()
         }
 
-        /* Force logout users who are logged in with OAuth 1.0a, they need to re-authenticate with OAuth 2 */
+        // Force logout users who are logged in with OAuth 1.0a, they need to re-authenticate with OAuth 2
         if (prefs.getStringOrNull(Prefs.OAUTH1_ACCESS_TOKEN) != null) {
             userLoginStatusController.logOut()
         }
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/Cleaner.kt b/app/src/main/java/de/westnordost/streetcomplete/data/Cleaner.kt
index 74004d6529c..ec6012bd8bb 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/data/Cleaner.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/Cleaner.kt
@@ -28,7 +28,7 @@ class Cleaner(
         noteController.deleteOlderThan(oldDataTimestamp, MAX_DELETE_ELEMENTS)
         mapDataController.deleteOlderThan(oldDataTimestamp, MAX_DELETE_ELEMENTS)
         downloadedTilesController.deleteOlderThan(oldDataTimestamp)
-        /* do this after cleaning map data and notes, because some metadata rely on map data */
+        // do this after cleaning map data and notes, because some metadata rely on map data
         questTypeRegistry.forEach { it.deleteMetadataOlderThan(oldDataTimestamp) }
 
         val oldLogTimestamp = nowAsEpochMilliseconds() - ApplicationConstants.DELETE_OLD_LOG_AFTER
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/DatabaseInitializer.kt b/app/src/main/java/de/westnordost/streetcomplete/data/DatabaseInitializer.kt
index 497a9bda571..dd8f20c8dd7 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/data/DatabaseInitializer.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/DatabaseInitializer.kt
@@ -29,7 +29,7 @@ import de.westnordost.streetcomplete.quests.oneway_suspects.data.WayTrafficFlowT
 
 /** Creates the database and upgrades it */
 object DatabaseInitializer {
-    const val DB_VERSION = 15
+    const val DB_VERSION = 16
 
     fun onCreate(db: Database) {
         // OSM notes
@@ -243,9 +243,22 @@ object DatabaseInitializer {
         if (oldVersion <= 14 && newVersion > 14) {
             db.renameOverlay("ShopsOverlay", "PlacesOverlay")
         }
+        if (oldVersion <= 15 && newVersion > 15) {
+            db.deleteQuest("AddCrossingType")
+        }
     }
 }
 
+private fun Database.deleteQuest(name: String) {
+    deleteValue(ElementEditsTable.NAME, ElementEditsTable.Columns.QUEST_TYPE, name)
+    deleteValue(OsmQuestTable.NAME, OsmQuestTable.Columns.QUEST_TYPE, name)
+    deleteValue(OsmQuestsHiddenTable.NAME, OsmQuestsHiddenTable.Columns.QUEST_TYPE, name)
+    deleteValue(VisibleQuestTypeTable.NAME, VisibleQuestTypeTable.Columns.QUEST_TYPE, name)
+    deleteValue(OpenChangesetsTable.NAME, OpenChangesetsTable.Columns.QUEST_TYPE, name)
+    deleteValue(QuestTypeOrderTable.NAME, QuestTypeOrderTable.Columns.BEFORE, name)
+    deleteValue(QuestTypeOrderTable.NAME, QuestTypeOrderTable.Columns.AFTER, name)
+}
+
 private fun Database.renameQuest(old: String, new: String) {
     renameValue(ElementEditsTable.NAME, ElementEditsTable.Columns.QUEST_TYPE, old, new)
     renameValue(OsmQuestTable.NAME, OsmQuestTable.Columns.QUEST_TYPE, old, new)
@@ -264,3 +277,7 @@ private fun Database.renameOverlay(old: String, new: String) {
 private fun Database.renameValue(table: String, column: String, oldValue: String, newValue: String) {
     update(table, listOf(column to newValue), "$column = ?", arrayOf(oldValue))
 }
+
+private fun Database.deleteValue(table: String, column: String, value: String) {
+    delete(table, "$column = ?", arrayOf(value))
+}
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/elementfilter/ElementFilterExpression.kt b/app/src/main/java/de/westnordost/streetcomplete/data/elementfilter/ElementFilterExpression.kt
index 82c51440201..2f95122afac 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/data/elementfilter/ElementFilterExpression.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/elementfilter/ElementFilterExpression.kt
@@ -70,7 +70,7 @@ class ElementFilterExpression(
     internal val elementsTypes: Set<ElementsTypeFilter>,
     internal val elementExprRoot: BooleanExpression<ElementFilter, Element>?
 ) {
-    /* Performance improvement: Allows to skip early on elements that have no tags at all */
+    // Performance improvement: Allows to skip early on elements that have no tags at all
     val mayEvaluateToTrueWithNoTags = elementExprRoot?.mayEvaluateToTrueWithNoTags ?: true
 
     /** returns whether the given element is found through (=matches) this expression */
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/elementfilter/ElementFiltersParser.kt b/app/src/main/java/de/westnordost/streetcomplete/data/elementfilter/ElementFiltersParser.kt
index 44a5da73c87..4feed50eef5 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/data/elementfilter/ElementFiltersParser.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/elementfilter/ElementFiltersParser.kt
@@ -316,7 +316,7 @@ private fun StringWithCursor.parseQuotedWord(quot: Char): String? {
     val word = advanceBy(length)
     return word
         .substring(1, word.length - 1) // remove quotes
-        .replace("\\$quot", "$quot")  // unescape quotes within string
+        .replace("\\$quot", "$quot") // unescape quotes within string
 }
 
 private fun StringWithCursor.parseWord(): String {
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/location/RecentLocationStore.kt b/app/src/main/java/de/westnordost/streetcomplete/data/location/RecentLocationStore.kt
index 51184f7568d..30c64b405a1 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/data/location/RecentLocationStore.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/location/RecentLocationStore.kt
@@ -1,9 +1,11 @@
 package de.westnordost.streetcomplete.data.location
 
 import android.location.Location
+import de.westnordost.streetcomplete.util.ktx.elapsedDuration
 import de.westnordost.streetcomplete.util.ktx.toLatLon
 import de.westnordost.streetcomplete.util.math.flatDistanceTo
-import kotlin.math.abs
+import kotlin.time.Duration.Companion.minutes
+import kotlin.time.Duration.Companion.seconds
 
 class RecentLocationStore {
     private val recentLocations = ArrayDeque<Location>()
@@ -17,7 +19,7 @@ class RecentLocationStore {
                 previousLocation = it
                 return@filter true
             }
-            if (abs(it.elapsedRealtimeNanos - loc.elapsedRealtimeNanos) > LOCATION_MIN_TIME_DIFFERENCE_NANOS
+            if ((it.elapsedDuration - loc.elapsedDuration).absoluteValue > LOCATION_MIN_TIME_DIFFERENCE
                 && loc.toLatLon().flatDistanceTo(it.toLatLon()) >= MAX_DISTANCE_TO_ELEMENT_FOR_SURVEY / 2
             ) {
                 previousLocation = it
@@ -30,13 +32,15 @@ class RecentLocationStore {
 
     fun add(location: Location) = synchronized(recentLocations) {
         while (recentLocations.isNotEmpty()
-            && recentLocations.first().elapsedRealtimeNanos <= location.elapsedRealtimeNanos - LOCATION_STORE_TIME_NANOS
+            && recentLocations.first().elapsedDuration <= location.elapsedDuration - LOCATION_STORE_TIME
         ) {
             recentLocations.removeFirst()
         }
         recentLocations.add(location)
     }
-}
 
-private const val LOCATION_STORE_TIME_NANOS = 600 * 1000 * 1000 * 1000L // 10 min
-private const val LOCATION_MIN_TIME_DIFFERENCE_NANOS = 5 * 1000 * 1000 * 1000L // 5 sec
+    companion object {
+        private val LOCATION_STORE_TIME = 10.minutes
+        private val LOCATION_MIN_TIME_DIFFERENCE = 5.seconds
+    }
+}
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/osm/edits/MapDataWithEditsSource.kt b/app/src/main/java/de/westnordost/streetcomplete/data/osm/edits/MapDataWithEditsSource.kt
index 11992a92d5b..354ecbeaaa3 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/data/osm/edits/MapDataWithEditsSource.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/osm/edits/MapDataWithEditsSource.kt
@@ -284,7 +284,7 @@ class MapDataWithEditsSource internal constructor(
         val ids = way.nodeIds.toHashSet()
         val nodes = getNodes(ids)
 
-        /* If the way is (now) not complete, this is not acceptable */
+        // If the way is (now) not complete, this is not acceptable
         if (nodes.size < ids.size) {
             Log.w(TAG, "could not find nodes ${ids - nodes.map { it.id }} for way $way")
             return null
@@ -324,7 +324,7 @@ class MapDataWithEditsSource internal constructor(
     private fun getRelationElements(relation: Relation): MutableMapData = synchronized(this) {
         val elements = ArrayList<Element>()
         for (member in relation.members) {
-            /* for way members, also get their nodes */
+            // for way members, also get their nodes
             if (member.type == WAY) {
                 val wayComplete = getWayComplete(member.ref)
                 if (wayComplete != null) {
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/AvatarsDownloader.kt b/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/AvatarsDownloader.kt
index 2f5aa0ba454..2eb939723d1 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/AvatarsDownloader.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/AvatarsDownloader.kt
@@ -3,19 +3,23 @@ package de.westnordost.streetcomplete.data.osmnotes
 import de.westnordost.osmapi.user.UserApi
 import de.westnordost.streetcomplete.util.ktx.format
 import de.westnordost.streetcomplete.util.ktx.nowAsEpochMilliseconds
-import de.westnordost.streetcomplete.util.ktx.saveToFile
 import de.westnordost.streetcomplete.util.logs.Log
+import io.ktor.client.HttpClient
+import io.ktor.client.plugins.expectSuccess
+import io.ktor.client.request.get
+import io.ktor.client.statement.bodyAsChannel
+import io.ktor.util.cio.writeChannel
+import io.ktor.utils.io.copyAndClose
 import java.io.File
-import java.io.IOException
-import java.net.URL
 
 /** Downloads and stores the OSM avatars of users */
 class AvatarsDownloader(
+    private val httpClient: HttpClient,
     private val userApi: UserApi,
     private val cacheDir: File
 ) {
 
-    fun download(userIds: Collection<Long>) {
+    suspend fun download(userIds: Collection<Long>) {
         if (!ensureCacheDirExists()) {
             Log.w(TAG, "Unable to create directories for avatars")
             return
@@ -41,13 +45,16 @@ class AvatarsDownloader(
         }
 
     /** download avatar for the given user and a known avatar url */
-    fun download(userId: Long, avatarUrl: String) {
+    suspend fun download(userId: Long, avatarUrl: String) {
         if (!ensureCacheDirExists()) return
+        val avatarFile = File(cacheDir, "$userId")
         try {
-            val avatarFile = File(cacheDir, "$userId")
-            URL(avatarUrl).saveToFile(avatarFile)
+            val response = httpClient.get(avatarUrl) {
+                expectSuccess = true
+            }
+            response.bodyAsChannel().copyAndClose(avatarFile.writeChannel())
             Log.d(TAG, "Downloaded file: ${avatarFile.path}")
-        } catch (e: IOException) {
+        } catch (e: Exception) {
             Log.w(TAG, "Unable to download avatar for user id $userId")
         }
     }
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/AvatarsInNotesUpdater.kt b/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/AvatarsInNotesUpdater.kt
index aecde11a3ce..98fc8b984b7 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/AvatarsInNotesUpdater.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/AvatarsInNotesUpdater.kt
@@ -1,4 +1,5 @@
 package de.westnordost.streetcomplete.data.osmnotes
+import kotlinx.coroutines.runBlocking
 
 class AvatarsInNotesUpdater(private val downloader: AvatarsDownloader) :
     NoteController.Listener {
@@ -7,7 +8,7 @@ class AvatarsInNotesUpdater(private val downloader: AvatarsDownloader) :
         if (added.isEmpty() && updated.isEmpty()) return
 
         val noteCommentUserIds = (added + updated).flatMap { it.userIds }.toSet()
-        downloader.download(noteCommentUserIds)
+        runBlocking { downloader.download(noteCommentUserIds) }
     }
 
     override fun onCleared() {}
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/NotesModule.kt b/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/NotesModule.kt
index 85f1c4fc2f4..183a8082929 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/NotesModule.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/NotesModule.kt
@@ -8,11 +8,11 @@ import java.io.File
 
 val notesModule = module {
     factory(named("AvatarsCacheDirectory")) { File(get<Context>().cacheDir, ApplicationConstants.AVATARS_CACHE_DIRECTORY) }
-    factory { AvatarsDownloader(get(), get(named("AvatarsCacheDirectory"))) }
+    factory { AvatarsDownloader(get(), get(), get(named("AvatarsCacheDirectory"))) }
     factory { AvatarsInNotesUpdater(get()) }
     factory { NoteDao(get()) }
     factory { NotesDownloader(get(), get()) }
-    factory { StreetCompleteImageUploader(ApplicationConstants.SC_PHOTO_SERVICE_URL) }
+    factory { StreetCompleteImageUploader(get(), ApplicationConstants.SC_PHOTO_SERVICE_URL) }
 
     single {
         NoteController(get()).apply {
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/StreetCompleteImageUploader.kt b/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/StreetCompleteImageUploader.kt
index a7c83657da1..5aa5ddb1849 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/StreetCompleteImageUploader.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/StreetCompleteImageUploader.kt
@@ -1,16 +1,22 @@
 package de.westnordost.streetcomplete.data.osmnotes
 
-import de.westnordost.streetcomplete.ApplicationConstants
 import de.westnordost.streetcomplete.data.download.ConnectionException
+import io.ktor.client.HttpClient
+import io.ktor.client.call.body
+import io.ktor.client.request.header
+import io.ktor.client.request.post
+import io.ktor.client.request.setBody
+import io.ktor.http.ContentType
+import io.ktor.http.HttpStatusCode
+import io.ktor.http.contentType
+import io.ktor.http.defaultForFile
+import io.ktor.util.cio.readChannel
+import io.ktor.utils.io.errors.IOException
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
 import kotlinx.serialization.SerializationException
 import kotlinx.serialization.json.Json
 import java.io.File
-import java.io.IOException
-import java.net.HttpURLConnection
-import java.net.URL
-import java.net.URLConnection
 
 @Serializable
 private data class PhotoUploadResponse(
@@ -19,9 +25,12 @@ private data class PhotoUploadResponse(
 )
 
 /** Upload and activate a list of image paths to an instance of the
- * <a href="https://github.com/exploide/sc-photo-service">StreetComplete image hosting service</a>
+ * <a href="https://github.com/streetcomplete/sc-photo-service">StreetComplete image hosting service</a>
  */
-class StreetCompleteImageUploader(private val baseUrl: String) {
+class StreetCompleteImageUploader(
+    private val httpClient: HttpClient,
+    private val baseUrl: String
+) {
     private val json = Json {
         ignoreUnknownKeys = true
     }
@@ -31,7 +40,7 @@ class StreetCompleteImageUploader(private val baseUrl: String) {
      *  @throws ImageUploadServerException when there was a server error on upload (server error)
      *  @throws ImageUploadClientException when the server rejected the upload request (client error)
      *  @throws ConnectionException if it is currently not reachable (no internet etc) */
-    fun upload(imagePaths: List<String>): List<String> {
+    suspend fun upload(imagePaths: List<String>): List<String> {
         val imageLinks = ArrayList<String>()
 
         for (path in imagePaths) {
@@ -39,35 +48,28 @@ class StreetCompleteImageUploader(private val baseUrl: String) {
             if (!file.exists()) continue
 
             try {
-                val connection = createConnection("upload.php")
-                connection.requestMethod = "POST"
-                connection.setRequestProperty("Content-Type", URLConnection.guessContentTypeFromName(file.path))
-                connection.setRequestProperty("Content-Transfer-Encoding", "binary")
-                connection.setRequestProperty("Content-Length", file.length().toString())
-                connection.outputStream.use { output ->
-                    file.inputStream().use { input ->
-                        input.copyTo(output)
-                    }
+                val response = httpClient.post(baseUrl + "upload.php") {
+                    contentType(ContentType.defaultForFile(file))
+                    header("Content-Transfer-Encoding", "binary")
+                    setBody(file.readChannel())
                 }
 
-                val status = connection.responseCode
-                if (status == HttpURLConnection.HTTP_OK) {
-                    val response = connection.inputStream.bufferedReader().use { it.readText() }
+                val status = response.status
+                val body = response.body<String>()
+                if (status == HttpStatusCode.OK) {
                     try {
-                        val parsedResponse = json.decodeFromString<PhotoUploadResponse>(response)
+                        val parsedResponse = json.decodeFromString<PhotoUploadResponse>(body)
                         imageLinks.add(parsedResponse.futureUrl)
                     } catch (e: SerializationException) {
-                        throw ImageUploadServerException("Upload Failed: Unexpected response \"$response\"")
+                        throw ImageUploadServerException("Upload Failed: Unexpected response \"$body\"")
                     }
                 } else {
-                    val error = connection.errorStream.bufferedReader().use { it.readText() }
-                    if (status / 100 == 5) {
-                        throw ImageUploadServerException("Upload failed: Error code $status, Message: \"$error\"")
+                    if (status.value / 100 == 5) {
+                        throw ImageUploadServerException("Upload failed: Error code $status, Message: \"$body\"")
                     } else {
-                        throw ImageUploadClientException("Upload failed: Error code $status, Message: \"$error\"")
+                        throw ImageUploadClientException("Upload failed: Error code $status, Message: \"$body\"")
                     }
                 }
-                connection.disconnect()
             } catch (e: IOException) {
                 throw ConnectionException("Upload failed", e)
             }
@@ -80,39 +82,29 @@ class StreetCompleteImageUploader(private val baseUrl: String) {
      *  @throws ImageUploadServerException when there was a server error on upload (server error)
      *  @throws ImageUploadClientException when the server rejected the upload request (client error)
      *  @throws ConnectionException if it is currently not reachable (no internet etc)  */
-    fun activate(noteId: Long) {
+    suspend fun activate(noteId: Long) {
         try {
-            val connection = createConnection("activate.php")
-            connection.requestMethod = "POST"
-            connection.setRequestProperty("Content-Type", "Content-Type: application/json")
-            connection.outputStream.bufferedWriter().use { it.write("{\"osm_note_id\": $noteId}") }
+            val response = httpClient.post(baseUrl + "activate.php") {
+                contentType(ContentType.Application.Json)
+                setBody("{\"osm_note_id\": $noteId}")
+            }
 
-            val status = connection.responseCode
-            if (status == HttpURLConnection.HTTP_GONE) {
+            val status = response.status
+            if (status == HttpStatusCode.Gone) {
                 // it's gone if the note does not exist anymore. That's okay, it should only fail
                 // if we might want to try again later.
-            } else if (status != HttpURLConnection.HTTP_OK) {
-                val error = connection.errorStream.bufferedReader().use { it.readText() }
-                if (status / 100 == 5) {
+            } else if (status != HttpStatusCode.OK) {
+                val error = response.body<String>()
+                if (status.value / 100 == 5) {
                     throw ImageUploadServerException("Error code $status, Message: \"$error\"")
                 } else {
                     throw ImageUploadClientException("Error code $status, Message: \"$error\"")
                 }
             }
-            connection.disconnect()
         } catch (e: IOException) {
             throw ConnectionException("", e)
         }
     }
-
-    private fun createConnection(url: String): HttpURLConnection {
-        val connection = URL(baseUrl + url).openConnection() as HttpURLConnection
-        connection.useCaches = false
-        connection.doOutput = true
-        connection.doInput = true
-        connection.setRequestProperty("User-Agent", ApplicationConstants.USER_AGENT)
-        return connection
-    }
 }
 
 class ImageUploadServerException(message: String? = null, cause: Throwable? = null) :
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/edits/NoteEditsUploader.kt b/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/edits/NoteEditsUploader.kt
index 144022498f9..e21210bc3ca 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/edits/NoteEditsUploader.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/osmnotes/edits/NoteEditsUploader.kt
@@ -14,6 +14,7 @@ import de.westnordost.streetcomplete.data.upload.OnUploadedChangeListener
 import de.westnordost.streetcomplete.data.user.UserDataSource
 import de.westnordost.streetcomplete.util.ktx.truncate
 import de.westnordost.streetcomplete.util.logs.Log
+import io.ktor.http.encodeURLPathPart
 import kotlinx.coroutines.CoroutineName
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
@@ -21,7 +22,6 @@ import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
 import kotlinx.coroutines.withContext
-import java.net.URLEncoder
 
 class NoteEditsUploader(
     private val noteEditsController: NoteEditsController,
@@ -51,7 +51,7 @@ class NoteEditsUploader(
     private suspend fun uploadMissedImageActivations() {
         while (true) {
             val edit = noteEditsController.getOldestNeedingImagesActivation() ?: break
-            /* see uploadEdits */
+            // see uploadEdits
             withContext(scope.coroutineContext) {
                 imageUploader.activate(edit.noteId)
                 noteEditsController.markImagesActivated(edit.id)
@@ -69,7 +69,7 @@ class NoteEditsUploader(
         }
     }
 
-    private fun uploadEdit(edit: NoteEdit) {
+    private suspend fun uploadEdit(edit: NoteEdit) {
         // try to upload the image and track if we have them
         val imageText = uploadAndGetAttachedPhotosText(edit.imagePaths)
         val trackText = uploadAndGetAttachedTrackText(edit.track, edit.text)
@@ -118,7 +118,7 @@ class NoteEditsUploader(
         }
     }
 
-    private fun uploadAndGetAttachedPhotosText(imagePaths: List<String>): String {
+    private suspend fun uploadAndGetAttachedPhotosText(imagePaths: List<String>): String {
         if (imagePaths.isNotEmpty()) {
             val urls = imageUploader.upload(imagePaths)
             if (urls.isNotEmpty()) {
@@ -134,7 +134,7 @@ class NoteEditsUploader(
     ): String {
         if (trackpoints.isEmpty()) return ""
         val trackId = tracksApi.create(trackpoints, noteText?.truncate(255))
-        val encodedUsername = URLEncoder.encode(userDataSource.userName, "utf-8").replace("+", "%20")
+        val encodedUsername = userDataSource.userName!!.encodeURLPathPart()
         return "\n\nGPS Trace: https://www.openstreetmap.org/user/$encodedUsername/traces/$trackId\n"
     }
 
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/upload/UploadModule.kt b/app/src/main/java/de/westnordost/streetcomplete/data/upload/UploadModule.kt
index 6a417c92d66..137eb6d3c33 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/data/upload/UploadModule.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/upload/UploadModule.kt
@@ -8,7 +8,7 @@ import org.koin.core.qualifier.named
 import org.koin.dsl.module
 
 val uploadModule = module {
-    factory { VersionIsBannedChecker(BANNED_VERSION_URL, ApplicationConstants.USER_AGENT) }
+    factory { VersionIsBannedChecker(get(), BANNED_VERSION_URL, ApplicationConstants.USER_AGENT) }
 
     single { Uploader(get(), get(), get(), get(), get(), get(named("SerializeSync")), get(), get()) }
     /* uploading and downloading should be serialized, i.e. may not run in parallel, to avoid
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/upload/Uploader.kt b/app/src/main/java/de/westnordost/streetcomplete/data/upload/Uploader.kt
index 90c370d5b7f..34ed534b4a4 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/data/upload/Uploader.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/upload/Uploader.kt
@@ -33,7 +33,7 @@ class Uploader(
 
     private val listeners = Listeners<UploadProgressSource.Listener>()
 
-    private val bannedInfo by lazy { versionIsBannedChecker.get() }
+    private lateinit var bannedInfo: BannedInfo
 
     private val uploadedChangeRelay = object : OnUploadedChangeListener {
         override fun onUploaded(questType: String, at: LatLon) {
@@ -58,7 +58,11 @@ class Uploader(
         try {
             isUploadInProgress = true
             listeners.forEach { it.onStarted() }
-            val banned = withContext(Dispatchers.IO) { bannedInfo }
+
+            if (!::bannedInfo.isInitialized) {
+                bannedInfo = withContext(Dispatchers.IO) { versionIsBannedChecker.get() }
+            }
+            val banned = bannedInfo
             if (banned is IsBanned) {
                 throw VersionBannedException(banned.reason)
             } else if (banned is UnknownIfBanned) {
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/upload/VersionIsBannedChecker.kt b/app/src/main/java/de/westnordost/streetcomplete/data/upload/VersionIsBannedChecker.kt
index 588d5fb45f9..dab553559e6 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/data/upload/VersionIsBannedChecker.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/upload/VersionIsBannedChecker.kt
@@ -1,30 +1,33 @@
 package de.westnordost.streetcomplete.data.upload
 
-import java.io.IOException
-import java.net.HttpURLConnection
-import java.net.URL
+import io.ktor.client.HttpClient
+import io.ktor.client.call.body
+import io.ktor.client.plugins.expectSuccess
+import io.ktor.client.request.get
 
 /** Asks remote server if this version of the app is banned */
-class VersionIsBannedChecker(private val url: String, private val userAgent: String) {
+class VersionIsBannedChecker(
+    private val httpClient: HttpClient,
+    private val url: String,
+    private val userAgent: String
+) {
 
-    fun get(): BannedInfo {
-        var connection: HttpURLConnection? = null
+    suspend fun get(): BannedInfo {
         try {
-            connection = (URL(url).openConnection() as HttpURLConnection)
-            connection.inputStream.bufferedReader().use { reader ->
-                for (line in reader.lineSequence()) {
-                    val text = line.split("\t".toRegex())
-                    if (text[0] == userAgent) {
-                        return IsBanned(if (text.size > 1) text[1] else null)
-                    }
+            val response = httpClient.get(url) {
+                expectSuccess = true
+            }
+            val bannedVersions = response.body<String>()
+            for (bannedVersion in bannedVersions.lines()) {
+                val destructuredVersion = bannedVersion.split("\t")
+                if (destructuredVersion[0] == userAgent) {
+                    return IsBanned(if (destructuredVersion.size > 1) destructuredVersion[1] else null)
                 }
             }
-        } catch (e: IOException) {
+        } catch (e: Exception) {
             // if there is an io exception, never mind then...! (The unreachability of the above
             // internet address should not lead to this app being unusable!)
             return UnknownIfBanned
-        } finally {
-            connection?.disconnect()
         }
         return IsNotBanned
     }
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/urlconfig/UrlConfig.kt b/app/src/main/java/de/westnordost/streetcomplete/data/urlconfig/UrlConfig.kt
index 3f797c32809..b90f7ada333 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/data/urlconfig/UrlConfig.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/urlconfig/UrlConfig.kt
@@ -4,8 +4,8 @@ import de.westnordost.streetcomplete.data.overlays.OverlayRegistry
 import de.westnordost.streetcomplete.data.quest.QuestType
 import de.westnordost.streetcomplete.data.quest.QuestTypeRegistry
 import de.westnordost.streetcomplete.overlays.Overlay
-import java.net.URLDecoder
-import java.net.URLEncoder
+import io.ktor.http.decodeURLQueryComponent
+import io.ktor.http.encodeURLQueryComponent
 
 data class UrlConfig(
     val presetName: String?,
@@ -45,7 +45,7 @@ fun parseConfigUrl(
             keyValue[0].lowercase() to keyValue[1]
         }
 
-    val name = parameters[PARAM_NAME]?.let { URLDecoder.decode(it, "UTF-8") }
+    val name = parameters[PARAM_NAME]?.let { it.decodeURLQueryComponent(plusIsSpace = true) }
 
     val questTypesString = parameters[PARAM_QUESTS] ?: return null
     val questTypes = stringToQuestTypes(questTypesString, questTypeRegistry) ?: return null
@@ -79,7 +79,7 @@ fun createConfigUrl(
     val name = urlConfig.presetName
     if (name != null) {
         val shortenedName = if (name.length > 60) name.substring(0, 57) + "..." else name
-        parameters.add(PARAM_NAME to URLEncoder.encode(shortenedName, "UTF-8"))
+        parameters.add(PARAM_NAME to shortenedName.encodeURLQueryComponent(spaceToPlus = true))
     }
     parameters.add(PARAM_QUESTS to questTypesToString(urlConfig.questTypes, questTypeRegistry))
 
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/user/UserModule.kt b/app/src/main/java/de/westnordost/streetcomplete/data/user/UserModule.kt
index e05e6f340ef..6827f32ff98 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/data/user/UserModule.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/user/UserModule.kt
@@ -1,5 +1,6 @@
 package de.westnordost.streetcomplete.data.user
 
+import de.westnordost.streetcomplete.data.user.oauth.OAuthService
 import org.koin.dsl.module
 
 const val OAUTH2_TOKEN_URL = "https://www.openstreetmap.org/oauth2/token"
@@ -42,4 +43,6 @@ val userModule = module {
     single { UserLoginStatusController(get(), get()) }
 
     single { UserUpdater(get(), get(), get(), get(), get()) }
+
+    single { OAuthService(get()) }
 }
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/user/oauth/OAuthAuthorization.kt b/app/src/main/java/de/westnordost/streetcomplete/data/user/oauth/OAuthAuthorization.kt
deleted file mode 100644
index b3af4291485..00000000000
--- a/app/src/main/java/de/westnordost/streetcomplete/data/user/oauth/OAuthAuthorization.kt
+++ /dev/null
@@ -1,198 +0,0 @@
-package de.westnordost.streetcomplete.data.user.oauth
-
-import de.westnordost.streetcomplete.ApplicationConstants
-import kotlinx.serialization.Serializable
-import kotlinx.serialization.SerializationException
-import kotlinx.serialization.Transient
-import kotlinx.serialization.json.Json
-import java.io.IOException
-import java.net.HttpURLConnection
-import java.net.URI
-import java.net.URL
-import java.net.URLDecoder
-import java.net.URLEncoder
-import java.nio.charset.StandardCharsets
-import java.security.MessageDigest
-import kotlin.io.encoding.Base64
-import kotlin.io.encoding.ExperimentalEncodingApi
-
-/**
- * One authorization with OAuth. For each authorization request, a new instance must be created
- *
- * Authorization flow:
- *
- * 1. createAuthorizationUrl() and open it in a browser (or web view)
- * 2. let user accept or deny the permission request in the browser (or web view). Authorization
- *    endpoint will call the redirect URI (aka callback URI) with parameters in either case.
- * 3. check if the URI received is for this instance with itsForMe(uri) and then
- *    extractAuthorizationCode(uri) from that URI
- * 4. retrieveAccessToken(authorizationCode) with the retrieved authorizationCode
- *
- *
- * @param authorizationUrl the OAuth2 server authorization endpoint
- * @param accessTokenUrl the OAuth2 server token endpoint
- * @param clientId the OAuth2 client id
- * @param scopes the scopes (aka permissions) to request
- * @param redirectUri the redirect URI (aka callback URI) that the authorization endpoint should
- *                    call when the user allowed the authorization.
- * @param state optional string to identify this oauth authorization flow, in case there are
- *              several at once (using the same redirect URI)
- */
-@Serializable class OAuthAuthorization(
-    private val authorizationUrl: String,
-    private val accessTokenUrl: String,
-    private val clientId: String,
-    private val scopes: List<String>,
-    private val redirectUri: String,
-    private val state: String? = null
-) {
-    /**
-     * For the code challenge as specified in RFC 7636
-     * https://www.rfc-editor.org/rfc/rfc7636
-     *
-     * and required in the OAuth 2.1 draft
-     * https://datatracker.ietf.org/doc/html/draft-ietf-oauth-v2-1-09
-     */
-    private val codeVerifier: String = createRandomAlphanumericString(128)
-
-    @Transient
-    private val json = Json { ignoreUnknownKeys = true }
-
-    /**
-     * Creates the URL to be opened in the browser or a web view in which the user agrees to
-     * authorize the requested permissions.
-     */
-    fun createAuthorizationUrl(): String =
-        authorizationUrl + "?" + listOfNotNull(
-            "response_type" to "code",
-            "client_id" to clientId,
-            "scope" to scopes.joinToString(" "),
-            "redirect_uri" to redirectUri,
-            "code_challenge_method" to "S256",
-            "code_challenge" to createPKCE_S256CodeChallenge(codeVerifier),
-            state?.let { "state" to it },
-        ).toUrlParameters()
-
-    /**
-     * Checks whether the given callback uri is meant for this instance
-     */
-    fun itsForMe(uri: URI): Boolean {
-        val uri2 = URI(redirectUri)
-        return uri.scheme == uri2.scheme && uri.authority == uri2.authority && uri.path == uri2.path
-            && uri.getQueryParameters()["state"] == state
-    }
-
-    /**
-     * Extracts the authorization code from a parameter of the callback uri
-     *
-     * @throws OAuthException if the URI does not contain the authorization code, e.g.
-     *                        the user did not accept the requested permissions
-     * @throws OAuthConnectionException if the server reply is malformed
-     */
-    fun extractAuthorizationCode(uri: URI): String {
-        val parameters = uri.getQueryParameters()
-        val authorizationCode = parameters["code"]
-        if (authorizationCode != null) return authorizationCode
-
-        val error = parameters["error"]
-            ?: throw OAuthConnectionException("OAuth 2 authorization endpoint did not return a valid error response: $uri")
-
-        throw OAuthException(error, parameters["error_description"], parameters["error_uri"])
-    }
-
-    /**
-     * Retrieves the access token, using the previously retrieved [authorizationCode]
-     *
-     * @throws OAuthException if there has been an OAuth authorization error
-     * @throws OAuthConnectionException if the server reply is malformed or there is an issue with
-     *                                   the connection
-     */
-    fun retrieveAccessToken(authorizationCode: String): AccessTokenResponse {
-        val url = accessTokenUrl + "?" + listOfNotNull(
-            "grant_type" to "authorization_code",
-            "client_id" to clientId,
-            "code" to authorizationCode,
-            "redirect_uri" to redirectUri,
-            "code_verifier" to codeVerifier,
-        ).toUrlParameters()
-
-        try {
-            val connection = URL(url).openConnection() as HttpURLConnection
-            connection.setRequestProperty("User-Agent", ApplicationConstants.USER_AGENT)
-            connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded")
-            connection.requestMethod = "POST"
-
-            if (connection.responseCode != HttpURLConnection.HTTP_OK) {
-                val body = connection.errorStream.bufferedReader().use { it.readText() }
-                val response = json.decodeFromString<ErrorResponseJson>(body)
-                throw OAuthException(response.error, response.error_description, response.error_uri)
-            } else {
-                val body = connection.inputStream.bufferedReader().use { it.readText() }
-                val response = json.decodeFromString<AccessTokenResponseJson>(body)
-                if (response.token_type.lowercase() != "bearer") {
-                    // hey! that's not what we asked for! (according to the RFC, the client MUST check this)
-                    throw OAuthConnectionException("OAuth 2 token endpoint returned an unknown token type (${response.token_type})")
-                }
-                return AccessTokenResponse(response.access_token, response.scope?.split(" "))
-            }
-        // if OSM server does not return valid JSON, it is the server's fault, hence
-        } catch (e: SerializationException) {
-            throw OAuthConnectionException("OAuth 2 token endpoint did not return a valid response", e)
-        } catch (e: IllegalArgumentException) {
-            throw OAuthConnectionException("OAuth 2 token endpoint did not return a valid response", e)
-        } catch (e: IOException) {
-            throw OAuthConnectionException(cause = e)
-        }
-    }
-}
-
-data class AccessTokenResponse(
-    val accessToken: String,
-    /** Granted scopes may be null if all requested scopes were granted */
-    val grantedScopes: List<String>? = null
-)
-
-@Serializable
-private data class AccessTokenResponseJson(
-    val access_token: String,
-    val token_type: String,
-    val scope: String? = null,
-    // OSM does currently not issue refresh tokens and the access token has no expiry date, so
-    // we can ignore the below
-    val expires_in: Long? = null,
-    val refresh_token: String? = null,
-)
-
-@Serializable
-private data class ErrorResponseJson(
-    val error: String,
-    val error_description: String? = null,
-    val error_uri: String? = null,
-)
-
-/**
- * Create the RFC 7636 Proof Key for Code Exchange from a random string.
- *
- * See https://www.rfc-editor.org/rfc/rfc7636
- */
-@OptIn(ExperimentalEncodingApi::class)
-private fun createPKCE_S256CodeChallenge(codeVerifier: String): String {
-    // S256: code_challenge = BASE64URL-ENCODE(SHA256(ASCII(code_verifier)))
-    val encodedBytes = codeVerifier.toByteArray(StandardCharsets.US_ASCII)
-    val sha256 = MessageDigest.getInstance("SHA-256").digest(encodedBytes)
-    return Base64.UrlSafe.encode(sha256).split("=")[0]
-}
-
-private fun Iterable<Pair<String, String>>.toUrlParameters(): String =
-    joinToString("&") { (k, v) -> k + "=" + URLEncoder.encode(v, "US-ASCII") }
-
-private fun createRandomAlphanumericString(length: Int): String {
-    val allowedChars = ('A'..'Z') + ('a'..'z') + ('0'..'9')
-    return (0 until length).map { allowedChars.random() }.joinToString("")
-}
-
-private fun URI.getQueryParameters(): Map<String, String> =
-    query?.split('&')?.associate {
-        val parts = it.split('=')
-        parts[0] to URLDecoder.decode(parts[1], "US-ASCII")
-    }.orEmpty()
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/user/oauth/OAuthService.kt b/app/src/main/java/de/westnordost/streetcomplete/data/user/oauth/OAuthService.kt
new file mode 100644
index 00000000000..66c80f6d675
--- /dev/null
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/user/oauth/OAuthService.kt
@@ -0,0 +1,202 @@
+package de.westnordost.streetcomplete.data.user.oauth
+
+import io.ktor.client.HttpClient
+import io.ktor.client.call.body
+import io.ktor.client.request.post
+import io.ktor.http.ContentType
+import io.ktor.http.HttpStatusCode
+import io.ktor.http.URLBuilder
+import io.ktor.http.URLParserException
+import io.ktor.http.Url
+import io.ktor.http.contentType
+import io.ktor.http.decodeURLQueryComponent
+import io.ktor.http.takeFrom
+import io.ktor.utils.io.errors.IOException
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.SerializationException
+import kotlinx.serialization.json.Json
+import java.nio.charset.StandardCharsets
+import java.security.MessageDigest
+import kotlin.io.encoding.Base64
+import kotlin.io.encoding.ExperimentalEncodingApi
+
+/**
+ * Authorization flow:
+ *
+ * 1. Generate and store a OAuthAuthorizationParams instance and open the authorizationRequestUrl
+ *    in a browser (or web view)
+ * 2. Let user accept or deny the permission request in the browser (or web view). Authorization
+ *    endpoint will call the redirect URI (aka callback URI) with parameters in either case.
+ * 3. Check if the URI received is matches the OAuthAuthorizationParams instance with itsForMe(uri)
+ *    and then extractAuthorizationCode(uri) from that URI
+ * 4. OAuthService.retrieveAccessToken(authorizationCode) with the retrieved authorizationCode
+ */
+class OAuthService(private val httpClient: HttpClient) {
+    private val json = Json { ignoreUnknownKeys = true }
+
+    /**
+     * Retrieves the access token, using the previously retrieved [authorizationCode]
+     *
+     * @throws OAuthException if there has been an OAuth authorization error
+     * @throws OAuthConnectionException if the server reply is malformed or there is an issue with
+     *                                   the connection
+     */
+    suspend fun retrieveAccessToken(request: OAuthAuthorizationParams, authorizationCode: String): AccessTokenResponse {
+        try {
+            val response = httpClient.post(request.accessTokenUrl) {
+                url {
+                    parameters.append("grant_type", "authorization_code")
+                    parameters.append("client_id", request.clientId)
+                    parameters.append("code", authorizationCode)
+                    parameters.append("redirect_uri", request.redirectUri)
+                    parameters.append("code_verifier", request.codeVerifier)
+                }
+                contentType(ContentType.Application.FormUrlEncoded)
+            }
+
+            if (response.status != HttpStatusCode.OK) {
+                val errorResponse = json.decodeFromString<ErrorResponseJson>(response.body())
+                throw OAuthException(errorResponse.error, errorResponse.error_description, errorResponse.error_uri)
+            } else {
+                val accessTokenResponse = json.decodeFromString<AccessTokenResponseJson>(response.body())
+                if (accessTokenResponse.token_type.lowercase() != "bearer") {
+                    throw OAuthConnectionException("OAuth 2 token endpoint returned an unknown token type (${accessTokenResponse.token_type})")
+                }
+                return AccessTokenResponse(accessTokenResponse.access_token, accessTokenResponse.scope?.split(" "))
+            }
+            // if OSM server does not return valid JSON, it is the server's fault, hence
+        } catch (e: SerializationException) {
+            throw OAuthConnectionException("OAuth 2 token endpoint did not return a valid response", e)
+        } catch (e: IllegalArgumentException) {
+            throw OAuthConnectionException("OAuth 2 token endpoint did not return a valid response", e)
+        } catch (e: IOException) {
+            throw OAuthConnectionException(cause = e)
+        }
+    }
+}
+
+/**
+ * One authorization with OAuth. For each authorization request, a new instance must be created
+ *
+ * @param authorizationUrl the OAuth2 server authorization endpoint
+ * @param accessTokenUrl the OAuth2 server token endpoint
+ * @param clientId the OAuth2 client id
+ * @param scopes the scopes (aka permissions) to request
+ * @param redirectUri the redirect URI (aka callback URI) that the authorization endpoint should
+ *                    call when the user allowed the authorization.
+ * @param state optional string to identify this oauth authorization flow, in case there are
+ *              several at once (using the same redirect URI)
+ */
+@Serializable data class OAuthAuthorizationParams(
+    val authorizationUrl: String,
+    val accessTokenUrl: String,
+    val clientId: String,
+    val scopes: List<String>,
+    val redirectUri: String,
+    val state: String? = null
+) {
+    /**
+     * For the code challenge as specified in RFC 7636
+     * https://www.rfc-editor.org/rfc/rfc7636
+     *
+     * and required in the OAuth 2.1 draft
+     * https://datatracker.ietf.org/doc/html/draft-ietf-oauth-v2-1-09
+     */
+    public val codeVerifier: String = createRandomAlphanumericString(128)
+
+    /**
+     * Creates the URL to be opened in the browser or a web view in which the user agrees to
+     * authorize the requested permissions.
+     */
+    val authorizationRequestUrl get() =
+        URLBuilder().takeFrom(authorizationUrl).apply {
+            parameters.append("response_type", "code")
+            parameters.append("client_id", clientId)
+            parameters.append("scope", scopes.joinToString(" "))
+            parameters.append("redirect_uri", redirectUri)
+            parameters.append("code_challenge_method", "S256")
+            parameters.append("code_challenge", createPKCE_S256CodeChallenge(codeVerifier))
+            state?.let { parameters.append("state", it) }
+        }.build().toString()
+
+    /**
+     * Checks whether the given callback uri is meant for this instance
+     */
+    fun itsForMe(callBackUri: String): Boolean = try {
+        itsForMe(Url(callBackUri))
+    } catch (e: URLParserException) {
+        false
+    }
+
+    private fun itsForMe(callbackUri: Url): Boolean {
+        val uri2 = Url(redirectUri)
+        return callbackUri.protocol == uri2.protocol
+            && callbackUri.host == uri2.host
+            && callbackUri.pathSegments == uri2.pathSegments
+            && callbackUri.parameters["state"] == state
+    }
+}
+
+/**
+ * Extracts the authorization code from a parameter of the callback uri
+ *
+ * @throws OAuthException if the URI does not contain the authorization code, e.g.
+ *                        the user did not accept the requested permissions
+ * @throws OAuthConnectionException if the server reply is malformed
+ */
+public fun extractAuthorizationCode(uri: String): String {
+    val parameters = Url(uri).parameters
+    val authorizationCode = parameters["code"]
+    if (authorizationCode != null) return authorizationCode
+
+    val error = parameters["error"]
+        ?: throw OAuthConnectionException("OAuth 2 authorization endpoint did not return a valid error response: $uri")
+
+    throw OAuthException(
+        error.decodeURLQueryComponent(plusIsSpace = true),
+        parameters["error_description"],
+        parameters["error_uri"]
+    )
+}
+
+data class AccessTokenResponse(
+    val accessToken: String,
+    /** Granted scopes may be null if all requested scopes were granted */
+    val grantedScopes: List<String>? = null
+)
+
+@Serializable
+private data class AccessTokenResponseJson(
+    val access_token: String,
+    val token_type: String,
+    val scope: String? = null,
+    // OSM does currently not issue refresh tokens and the access token has no expiry date, so
+    // we can ignore the below
+    val expires_in: Long? = null,
+    val refresh_token: String? = null,
+)
+
+@Serializable
+private data class ErrorResponseJson(
+    val error: String,
+    val error_description: String? = null,
+    val error_uri: String? = null,
+)
+
+/**
+ * Create the RFC 7636 Proof Key for Code Exchange from a random string.
+ *
+ * See https://www.rfc-editor.org/rfc/rfc7636
+ */
+@OptIn(ExperimentalEncodingApi::class)
+private fun createPKCE_S256CodeChallenge(codeVerifier: String): String {
+    // S256: code_challenge = BASE64URL-ENCODE(SHA256(ASCII(code_verifier)))
+    val encodedBytes = codeVerifier.toByteArray(StandardCharsets.US_ASCII)
+    val sha256 = MessageDigest.getInstance("SHA-256").digest(encodedBytes)
+    return Base64.UrlSafe.encode(sha256).split("=")[0]
+}
+
+private fun createRandomAlphanumericString(length: Int): String {
+    val allowedChars = ('A'..'Z') + ('a'..'z') + ('0'..'9')
+    return (0 until length).map { allowedChars.random() }.joinToString("")
+}
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/user/statistics/StatisticsDownloader.kt b/app/src/main/java/de/westnordost/streetcomplete/data/user/statistics/StatisticsDownloader.kt
index 5378fe9991a..8bf39e54035 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/data/user/statistics/StatisticsDownloader.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/user/statistics/StatisticsDownloader.kt
@@ -1,32 +1,20 @@
 package de.westnordost.streetcomplete.data.user.statistics
 
-import de.westnordost.streetcomplete.ApplicationConstants
-import java.io.IOException
-import java.net.HttpURLConnection
-import java.net.URL
+import io.ktor.client.HttpClient
+import io.ktor.client.call.body
+import io.ktor.client.plugins.expectSuccess
+import io.ktor.client.request.get
 
 /** Downloads statistics from the backend */
 class StatisticsDownloader(
+    private val httpClient: HttpClient,
     private val baseUrl: String,
     private val statisticsParser: StatisticsParser
 ) {
-    fun download(osmUserId: Long): Statistics {
-        (URL("$baseUrl?user_id=$osmUserId").openConnection() as HttpURLConnection).run {
-            useCaches = false
-            doOutput = true
-            doInput = true
-            setRequestProperty("User-Agent", ApplicationConstants.USER_AGENT)
-            requestMethod = "GET"
-            when (responseCode) {
-                HttpURLConnection.HTTP_OK -> {
-                    return statisticsParser.parse(inputStream.bufferedReader().use { it.readText() })
-                }
-                else -> {
-                    val errorMessage = responseMessage
-                    val errorDescription = errorStream?.bufferedReader()?.use { it.readText() }
-                    throw IOException("$responseCode $errorMessage: $errorDescription")
-                }
-            }
+    suspend fun download(osmUserId: Long): Statistics {
+        val response = httpClient.get("$baseUrl?user_id=$osmUserId") {
+            expectSuccess = true
         }
+        return statisticsParser.parse(response.body())
     }
 }
diff --git a/app/src/main/java/de/westnordost/streetcomplete/data/user/statistics/StatisticsModule.kt b/app/src/main/java/de/westnordost/streetcomplete/data/user/statistics/StatisticsModule.kt
index a48815219ed..daee508eb4f 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/data/user/statistics/StatisticsModule.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/data/user/statistics/StatisticsModule.kt
@@ -14,7 +14,7 @@ val statisticsModule = module {
 
     factory { ActiveDatesDao(get()) }
 
-    factory { StatisticsDownloader(STATISTICS_BACKEND_URL, get()) }
+    factory { StatisticsDownloader(get(), STATISTICS_BACKEND_URL, get()) }
     factory { StatisticsParser(get(named("TypeAliases"))) }
 
     single<StatisticsSource> { get<StatisticsController>() }
diff --git a/app/src/main/java/de/westnordost/streetcomplete/osm/Area.kt b/app/src/main/java/de/westnordost/streetcomplete/osm/Area.kt
index e4d70c8a876..3c88daf3a36 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/osm/Area.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/osm/Area.kt
@@ -14,7 +14,7 @@ val IS_AREA_EXPRESSION = """
 
 private fun isAreaExpressionFragment(prefix: String? = null): String {
     val p = if (prefix != null) "$prefix:" else ""
-    /* roughly sorted by occurrence count */
+    // roughly sorted by occurrence count
     return """
         ${p}building
         or ${p}landuse
diff --git a/app/src/main/java/de/westnordost/streetcomplete/osm/Place.kt b/app/src/main/java/de/westnordost/streetcomplete/osm/Place.kt
index f9c4e83337a..c0d4fe2e0ff 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/osm/Place.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/osm/Place.kt
@@ -34,9 +34,9 @@ fun Element.isPlace(): Boolean =
 private val IS_PLACE_EXPRESSION by lazy {
     val tags = mapOf(
         "amenity" to listOf(
-            /* grouped by subcategory, sorted by alphabet */
+            // grouped by subcategory, sorted by alphabet
 
-            /* sustenance */
+            // sustenance
             "bar",
             "biergarten",
             "cafe",
@@ -46,7 +46,7 @@ private val IS_PLACE_EXPRESSION by lazy {
             "pub",
             "restaurant",
 
-            /* education */
+            // education
             "childcare",
             "college",
             "dancing_school",
@@ -64,7 +64,7 @@ private val IS_PLACE_EXPRESSION by lazy {
             "training",
             "university",
 
-            /* transportation */
+            // transportation
             "boat_rental", // usually there is some kind of office, even if it is just a small stall
             "car_rental", // usually there is some kind of office
             "car_wash",
@@ -72,14 +72,14 @@ private val IS_PLACE_EXPRESSION by lazy {
             "motorcycle_rental",
             "vehicle_inspection",
 
-            /* financial */
+            // financial
             "bank",
             "bureau_de_change",
             "mobile_money_agent",
             "money_transfer",
             "payment_centre",
 
-            /* healthcare */
+            // healthcare
             "clinic",
             "dentist",
             "doctors",
@@ -90,7 +90,7 @@ private val IS_PLACE_EXPRESSION by lazy {
             "social_facility",
             "veterinary",
 
-            /* entertainment, arts & culture */
+            // entertainment, arts & culture
             "archive",
             "arts_centre",
             "brothel",
@@ -113,7 +113,7 @@ private val IS_PLACE_EXPRESSION by lazy {
             "swingerclub",
             "theatre",
 
-            /* public service */
+            // public service
             "courthouse",
             "embassy", // deprecated now
             "fire_station",
@@ -125,11 +125,11 @@ private val IS_PLACE_EXPRESSION by lazy {
             "ranger_station",
             "townhall",
 
-            /* facilities */
+            // facilities
             "lavoir",
             "left_luggage",
 
-            /* others */
+            // others
             "animal_boarding",
             "animal_shelter",
             "animal_training",
diff --git a/app/src/main/java/de/westnordost/streetcomplete/osm/Things.kt b/app/src/main/java/de/westnordost/streetcomplete/osm/Things.kt
index c8195b04ab9..333c9ab2468 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/osm/Things.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/osm/Things.kt
@@ -38,9 +38,9 @@ private val IS_THING_EXPRESSION by lazy {
             "windsock",
         ),
         "amenity" to listOf(
-            /* grouped by subcategory, sorted by alphabet */
+            // grouped by subcategory, sorted by alphabet
 
-            /* transportation */
+            // transportation
             "bicycle_parking",
             "bicycle_rental",
             "bicycle_repair_station",
@@ -56,23 +56,23 @@ private val IS_THING_EXPRESSION by lazy {
             "ticket_validator",
             "vacuum_cleaner",
 
-            /* financial */
+            // financial
             "atm",
             "payment_terminal",
 
-            /* healthcare */
+            // healthcare
             "baby_hatch",
             "kneipp_water_cure",
 
-            /* entertainment, arts & culture */
+            // entertainment, arts & culture
             "fountain",
             "public_bookcase",
             "whirlpool",
 
-            /* public service */
+            // public service
             // "post_box", - blocked by https://github.com/streetcomplete/StreetComplete/issues/4916
 
-            /* facilities & others */
+            // facilities & others
             "baking_oven",
             "bbq",
             "bench",
@@ -106,13 +106,13 @@ private val IS_THING_EXPRESSION by lazy {
             "water_point",
             "watering_place",
 
-            /* waste management */
+            // waste management
             // "recycling" only for containers, see bottom
             "sanitary_dump_station",
             "waste_basket",
             "waste_disposal",
 
-            /* animals */
+            // animals
             "feeding_place",
             "game_feeding",
             "hunting_stand",
diff --git a/app/src/main/java/de/westnordost/streetcomplete/osm/WaysCrossing.kt b/app/src/main/java/de/westnordost/streetcomplete/osm/WaysCrossing.kt
index 26b2e6624f5..b2e4fac3101 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/osm/WaysCrossing.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/osm/WaysCrossing.kt
@@ -20,7 +20,7 @@ data class WaysCrossing(val node: Node, var barrierWays: List<Way>, var movingWa
  */
 fun findNodesAtCrossingsOf(barrierWays: Sequence<Way>, movingWays: Sequence<Way>, mapData: MapData): Iterable<WaysCrossing> {
     val barriersByNodeId = barrierWays.groupByNodeIds()
-    /* filter out nodes of roads that are the end of a barrier not continuing further */
+    // filter out nodes of roads that are the end of a barrier not continuing further
     barriersByNodeId.removeEndNodes()
 
     val waysByNodeId = movingWays.groupByNodeIds()
@@ -32,7 +32,7 @@ fun findNodesAtCrossingsOf(barrierWays: Sequence<Way>, movingWays: Sequence<Way>
      * https://www.openstreetmap.org/node/56606744 (with roads) */
     waysByNodeId.removeEndNodes()
 
-    /* filter out all nodes that are not shared nodes of both a road and a footway */
+    // filter out all nodes that are not shared nodes of both a road and a footway
     barriersByNodeId.keys.retainAll(waysByNodeId.keys)
     waysByNodeId.keys.retainAll(barriersByNodeId.keys)
 
diff --git a/app/src/main/java/de/westnordost/streetcomplete/osm/address/StreetOrPlaceNameViewController.kt b/app/src/main/java/de/westnordost/streetcomplete/osm/address/StreetOrPlaceNameViewController.kt
index 051b23cb10a..eb59439fcb5 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/osm/address/StreetOrPlaceNameViewController.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/osm/address/StreetOrPlaceNameViewController.kt
@@ -57,7 +57,7 @@ class StreetOrPlaceNameViewController(
         }
         get() = when (spinnerSelection) {
             STREET -> streetNameInputCtrl.streetName?.let { StreetName(it) }
-            PLACE ->  placeNameInput.nonBlankTextOrNull?.let { PlaceName(it) }
+            PLACE -> placeNameInput.nonBlankTextOrNull?.let { PlaceName(it) }
         }
 
     private var spinnerSelection: StreetOrPlace
diff --git a/app/src/main/java/de/westnordost/streetcomplete/osm/building/BuildingType.kt b/app/src/main/java/de/westnordost/streetcomplete/osm/building/BuildingType.kt
index 4b72e35b352..04164507f24 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/osm/building/BuildingType.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/osm/building/BuildingType.kt
@@ -109,7 +109,7 @@ enum class BuildingType(val osmKey: String?, val osmValue: String?) {
             ("building" to "cottage") to BUNGALOW, // not documented
             ("building" to "ger") to TENT, // a Mongolian tent
             ("building" to "stilt_house") to HOUSE,
-            ("building" to "terrace_house") to HOUSE,  // not documented, auto-changing to house would be a loss of information
+            ("building" to "terrace_house") to HOUSE, // not documented, auto-changing to house would be a loss of information
             ("building" to "trullo") to HUT,
             ("building" to "pajaru") to HUT, // not documented, but similar to trullo https://it.wikipedia.org/wiki/Pajaru
 
diff --git a/app/src/main/java/de/westnordost/streetcomplete/osm/cycleway/Cycleway.kt b/app/src/main/java/de/westnordost/streetcomplete/osm/cycleway/Cycleway.kt
index f8e03549b49..9d5b7b8c2dc 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/osm/cycleway/Cycleway.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/osm/cycleway/Cycleway.kt
@@ -34,7 +34,7 @@ fun LeftAndRightCycleway.wasNoOnewayForCyclistsButNowItIs(tags: Map<String, Stri
  *  is null because it is possible that the undefined side has a track in the contra-flow direction
  *  (e.g. either a normal track on the left side or a dual-track on the right side) */
 fun LeftAndRightCycleway.isNotOnewayForCyclistsNow(tags: Map<String, String>): Boolean? {
-    val onewayDir = when  {
+    val onewayDir = when {
         isForwardOneway(tags) -> FORWARD
         isReversedOneway(tags) -> BACKWARD
         else -> return true
diff --git a/app/src/main/java/de/westnordost/streetcomplete/osm/cycleway/CyclewayCreator.kt b/app/src/main/java/de/westnordost/streetcomplete/osm/cycleway/CyclewayCreator.kt
index 45b640ad917..a6415b3a889 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/osm/cycleway/CyclewayCreator.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/osm/cycleway/CyclewayCreator.kt
@@ -53,7 +53,7 @@ fun LeftAndRightCycleway.applyTo(tags: Tags, isLeftHandTraffic: Boolean) {
     ).applyTo(tags)
 }
 
-/* bare cycleway tags are interpreted differently for oneways */
+// bare cycleway tags are interpreted differently for oneways
 private fun expandBareTags(tags: Tags, isLeftHandTraffic: Boolean) {
     val cycleway = tags["cycleway"] ?: return
     // i.e. they are only expanded into one side. Which side depends on country, direction of oneway
diff --git a/app/src/main/java/de/westnordost/streetcomplete/osm/lane_narrowing_traffic_calming/LaneNarrowingTrafficCalmingParser.kt b/app/src/main/java/de/westnordost/streetcomplete/osm/lane_narrowing_traffic_calming/LaneNarrowingTrafficCalmingParser.kt
index 74a4a5d9347..4e104b888bc 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/osm/lane_narrowing_traffic_calming/LaneNarrowingTrafficCalmingParser.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/osm/lane_narrowing_traffic_calming/LaneNarrowingTrafficCalmingParser.kt
@@ -33,7 +33,7 @@ internal fun expandTrafficCalmingValue(values: String): List<String> =
     values
         .split(';') // split e.g. choker;table;island
         .flatMap {
-            when  {
+            when {
                 // e.g. choked_table, choked_island... anything chocked_* is also a choker
                 it.startsWith("choked_") ->
                     listOf("choker", it.substringAfter('_'))
diff --git a/app/src/main/java/de/westnordost/streetcomplete/osm/sidewalk/SidewalkCreator.kt b/app/src/main/java/de/westnordost/streetcomplete/osm/sidewalk/SidewalkCreator.kt
index af291eee431..50e9b2d6f30 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/osm/sidewalk/SidewalkCreator.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/osm/sidewalk/SidewalkCreator.kt
@@ -27,7 +27,7 @@ fun LeftAndRightSidewalk.applyTo(tags: Tags) {
     tags.expandSides("sidewalk", includeBareTag = false)
     tags.separateConflatedSidewalk()
 
-    if (left != null)  tags["sidewalk:left"] = left.osmValue
+    if (left != null) tags["sidewalk:left"] = left.osmValue
     if (right != null) tags["sidewalk:right"] = right.osmValue
 
     // use shortcut syntax if possible, preferred by community according to usage numbers on taginfo
diff --git a/app/src/main/java/de/westnordost/streetcomplete/overlays/buildings/BuildingsOverlay.kt b/app/src/main/java/de/westnordost/streetcomplete/overlays/buildings/BuildingsOverlay.kt
index eca1665f201..29d1265d901 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/overlays/buildings/BuildingsOverlay.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/overlays/buildings/BuildingsOverlay.kt
@@ -23,7 +23,7 @@ class BuildingsOverlay : Overlay {
     override val achievements = listOf(BUILDING)
     override val hidesQuestTypes = setOf(AddBuildingType::class.simpleName!!)
 
-    /* building:use not supported, so don't offer to change it -> exclude from the overlay */
+    // building:use not supported, so don't offer to change it -> exclude from the overlay
     override fun getStyledElements(mapData: MapDataWithGeometry) = mapData.filter(
         """
             ways, relations with
diff --git a/app/src/main/java/de/westnordost/streetcomplete/overlays/cycleway/StreetCyclewayOverlayForm.kt b/app/src/main/java/de/westnordost/streetcomplete/overlays/cycleway/StreetCyclewayOverlayForm.kt
index f9b8c555937..b15cd0a22f0 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/overlays/cycleway/StreetCyclewayOverlayForm.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/overlays/cycleway/StreetCyclewayOverlayForm.kt
@@ -233,7 +233,7 @@ class StreetCyclewayOverlayForm : AStreetSideSelectOverlayForm<CyclewayAndDirect
         bicycleBoulevard == BicycleBoulevard.YES
 
     override fun hasChanges(): Boolean =
-        streetSideSelect.left?.value != originalCycleway?.left  ||
+        streetSideSelect.left?.value != originalCycleway?.left ||
         streetSideSelect.right?.value != originalCycleway?.right ||
         originalBicycleBoulevard != bicycleBoulevard
 
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/QuestsModule.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/QuestsModule.kt
index 41eedfee76d..76b4e2c1ff0 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/quests/QuestsModule.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/QuestsModule.kt
@@ -115,6 +115,7 @@ import de.westnordost.streetcomplete.quests.internet_access.AddInternetAccess
 import de.westnordost.streetcomplete.quests.kerb_height.AddKerbHeight
 import de.westnordost.streetcomplete.quests.lanes.AddLanes
 import de.westnordost.streetcomplete.quests.leaf_detail.AddForestLeafType
+import de.westnordost.streetcomplete.quests.leaf_detail.AddTreeLeafType
 import de.westnordost.streetcomplete.quests.level.AddLevel
 import de.westnordost.streetcomplete.quests.map.AddMapSize
 import de.westnordost.streetcomplete.quests.map.AddMapType
@@ -508,6 +509,7 @@ fun getQuestTypeList(
     105 to AddSummitCross(), // summit markings are not necessarily directly at the peak, need to look around
     106 to AddSummitRegister(), // register is harder to find than cross
 
+    165 to AddTreeLeafType(), // may need to get close in trickier cases
     107 to AddForestLeafType(), // need to walk around in the highlighted section
 
     108 to AddOrchardProduce(), // difficult to find out if the orchard does not carry fruits right now
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/address/AddAddressStreet.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/address/AddAddressStreet.kt
index b11087c8c4f..d03406f07c6 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/quests/address/AddAddressStreet.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/address/AddAddressStreet.kt
@@ -57,7 +57,7 @@ class AddAddressStreet : OsmElementQuestType<StreetOrPlaceName> {
         return addressesWithoutStreet
     }
 
-    /* cannot be determined because of the associated street relations */
+    // cannot be determined because of the associated street relations
     override fun isApplicableTo(element: Element): Boolean? =
         if (!filter.matches(element)) false else null
 
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/amenity_indoor/AddIsAmenityIndoor.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/amenity_indoor/AddIsAmenityIndoor.kt
index a6e72e1c00e..93ac7eafdf4 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/quests/amenity_indoor/AddIsAmenityIndoor.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/amenity_indoor/AddIsAmenityIndoor.kt
@@ -77,7 +77,7 @@ class AddIsAmenityIndoor(private val getFeature: (Element) -> Feature?) :
             buildings.any { building ->
                 val buildingGeometry = buildingGeometriesById[building.id]
 
-                if (buildingGeometry != null  && buildingGeometry.getBounds().contains(it.position)) {
+                if (buildingGeometry != null && buildingGeometry.getBounds().contains(it.position)) {
                     it.position.isInMultipolygon(buildingGeometry.polygons)
                 } else {
                     false
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/building_entrance_reference/AddEntranceReference.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/building_entrance_reference/AddEntranceReference.kt
index 4b17b94dc42..2762738a6ca 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/quests/building_entrance_reference/AddEntranceReference.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/building_entrance_reference/AddEntranceReference.kt
@@ -91,7 +91,7 @@ class AddEntranceReference : OsmElementQuestType<EntranceAnswer> {
                 is Relation -> building.getMultipolygonNodeIds(mapData).toHashSet()
                 else -> emptyList()
             }
-            val buildingEntrances =  buildingsWayNodeIds.mapNotNull { mapData.getNode(it) }
+            val buildingEntrances = buildingsWayNodeIds.mapNotNull { mapData.getNode(it) }
                 .filter { entrancesFilter.matches(it) }
             if (buildingEntrances.count() < 2) continue
             result.addAll(buildingEntrances.filter { noEntranceRefFilter.matches(it) && it.id !in excludedWayNodeIds })
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/existence/CheckExistence.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/existence/CheckExistence.kt
index 4592ab817a1..d22198e9ae9 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/quests/existence/CheckExistence.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/existence/CheckExistence.kt
@@ -61,6 +61,7 @@ class CheckExistence(
             or amenity = recycling and recycling_type = container
             or amenity = toilets
             or amenity = drinking_water
+            or man_made = planter
           )
           and (${lastChecked(6.0)})
         ) or (
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/leaf_detail/AddTreeLeafType.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/leaf_detail/AddTreeLeafType.kt
new file mode 100644
index 00000000000..22eb10df030
--- /dev/null
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/leaf_detail/AddTreeLeafType.kt
@@ -0,0 +1,37 @@
+package de.westnordost.streetcomplete.quests.leaf_detail
+
+import de.westnordost.streetcomplete.R
+import de.westnordost.streetcomplete.data.elementfilter.toElementFilterExpression
+import de.westnordost.streetcomplete.data.osm.geometry.ElementGeometry
+import de.westnordost.streetcomplete.data.osm.mapdata.Element
+import de.westnordost.streetcomplete.data.osm.mapdata.MapDataWithGeometry
+import de.westnordost.streetcomplete.data.osm.mapdata.filter
+import de.westnordost.streetcomplete.data.osm.osmquests.OsmFilterQuestType
+import de.westnordost.streetcomplete.data.user.achievements.EditTypeAchievement.OUTDOORS
+import de.westnordost.streetcomplete.osm.Tags
+
+class AddTreeLeafType : OsmFilterQuestType<TreeLeafType>() {
+    override val elementFilter = """
+        nodes with
+          natural = tree
+          and !leaf_type
+          and !~"(taxon|genus|species).*"
+    """
+    override val changesetComment = "Specify leaf types"
+    override val wikiLink = "Key:leaf_type"
+    override val icon = R.drawable.ic_quest_leaf
+    override val isDeleteElementEnabled = true
+    override val achievements = listOf(OUTDOORS)
+    override val defaultDisabledMessage = R.string.default_disabled_msg_difficult_and_time_consuming
+
+    override fun getTitle(tags: Map<String, String>) = R.string.quest_leafType_tree_title
+
+    override fun getHighlightedElements(element: Element, getMapData: () -> MapDataWithGeometry) =
+        getMapData().filter("nodes with natural = tree".toElementFilterExpression())
+
+    override fun createForm() = AddTreeLeafTypeForm()
+
+    override fun applyAnswerTo(answer: TreeLeafType, tags: Tags, geometry: ElementGeometry, timestampEdited: Long) {
+        tags["leaf_type"] = answer.osmValue
+    }
+}
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/leaf_detail/AddTreeLeafTypeForm.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/leaf_detail/AddTreeLeafTypeForm.kt
new file mode 100644
index 00000000000..454f26c6d81
--- /dev/null
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/leaf_detail/AddTreeLeafTypeForm.kt
@@ -0,0 +1,13 @@
+package de.westnordost.streetcomplete.quests.leaf_detail
+
+import de.westnordost.streetcomplete.quests.AImageListQuestForm
+
+class AddTreeLeafTypeForm : AImageListQuestForm<TreeLeafType, TreeLeafType>() {
+
+    override val items = TreeLeafType.entries.map { it.asItem() }
+    override val itemsPerRow = 2
+
+    override fun onClickOk(selectedItems: List<TreeLeafType>) {
+        applyAnswer(selectedItems.single())
+    }
+}
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/leaf_detail/ForestLeafTimeItem.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/leaf_detail/ForestLeafTypeItem.kt
similarity index 100%
rename from app/src/main/java/de/westnordost/streetcomplete/quests/leaf_detail/ForestLeafTimeItem.kt
rename to app/src/main/java/de/westnordost/streetcomplete/quests/leaf_detail/ForestLeafTypeItem.kt
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/leaf_detail/TreeLeafType.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/leaf_detail/TreeLeafType.kt
new file mode 100644
index 00000000000..48843c475dc
--- /dev/null
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/leaf_detail/TreeLeafType.kt
@@ -0,0 +1,6 @@
+package de.westnordost.streetcomplete.quests.leaf_detail
+
+enum class TreeLeafType(val osmValue: String) {
+    NEEDLELEAVED("needleleaved"),
+    BROADLEAVED("broadleaved"),
+}
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/leaf_detail/TreeLeafTypeItem.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/leaf_detail/TreeLeafTypeItem.kt
new file mode 100644
index 00000000000..a3ad87c0d6b
--- /dev/null
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/leaf_detail/TreeLeafTypeItem.kt
@@ -0,0 +1,18 @@
+package de.westnordost.streetcomplete.quests.leaf_detail
+
+import de.westnordost.streetcomplete.R
+import de.westnordost.streetcomplete.quests.leaf_detail.TreeLeafType.BROADLEAVED
+import de.westnordost.streetcomplete.quests.leaf_detail.TreeLeafType.NEEDLELEAVED
+import de.westnordost.streetcomplete.view.image_select.Item
+
+fun TreeLeafType.asItem() = Item(this, iconResId, titleResId)
+
+private val TreeLeafType.titleResId: Int get() = when (this) {
+    NEEDLELEAVED -> R.string.quest_leaf_type_needles
+    BROADLEAVED ->  R.string.quest_leaf_type_broadleaved
+}
+
+private val TreeLeafType.iconResId: Int get() = when (this) {
+    NEEDLELEAVED -> R.drawable.leaf_type_needleleaved
+    BROADLEAVED ->  R.drawable.leaf_type_broadleaved
+}
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/max_speed/AddMaxSpeedForm.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/max_speed/AddMaxSpeedForm.kt
index c30c4fc6f39..ed219c82091 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/quests/max_speed/AddMaxSpeedForm.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/max_speed/AddMaxSpeedForm.kt
@@ -383,7 +383,11 @@ class AddMaxSpeedForm : AbstractOsmQuestForm<Pair<MaxSpeedAnswer, Pair<String, S
     }
 
     companion object {
-        private val POSSIBLY_SLOWZONE_ROADS = listOf("residential", "unclassified", "tertiary" /*#1133*/)
+        private val POSSIBLY_SLOWZONE_ROADS = listOf(
+            "residential",
+            "unclassified",
+            "tertiary", // #1133
+        )
         private val MAYBE_LIVING_STREET = listOf("residential", "unclassified")
         private val ROADS_WITH_DEFINITE_SPEED_LIMIT = listOf("motorway", "living_street")
 
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/oneway_suspects/AddSuspectedOneway.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/oneway_suspects/AddSuspectedOneway.kt
index 30b4a45b33c..f603ed2d5b0 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/quests/oneway_suspects/AddSuspectedOneway.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/oneway_suspects/AddSuspectedOneway.kt
@@ -15,6 +15,7 @@ import de.westnordost.streetcomplete.quests.oneway_suspects.data.TrafficFlowSegm
 import de.westnordost.streetcomplete.quests.oneway_suspects.data.TrafficFlowSegmentsApi
 import de.westnordost.streetcomplete.quests.oneway_suspects.data.WayTrafficFlowDao
 import de.westnordost.streetcomplete.util.logs.Log
+import kotlinx.coroutines.runBlocking
 import kotlin.math.hypot
 
 class AddSuspectedOneway(
@@ -53,7 +54,7 @@ class AddSuspectedOneway(
 
         val trafficDirectionMap: Map<Long, List<TrafficFlowSegment>>
         try {
-            trafficDirectionMap = trafficFlowSegmentsApi.get(bbox)
+            runBlocking { trafficDirectionMap = trafficFlowSegmentsApi.get(bbox) }
         } catch (e: Exception) {
             Log.e("AddSuspectedOneway", "Unable to download traffic metadata", e)
             return emptyList()
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/oneway_suspects/data/TrafficFlowSegmentsApi.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/oneway_suspects/data/TrafficFlowSegmentsApi.kt
index ac2c95d0f3d..0af7d5ccd07 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/quests/oneway_suspects/data/TrafficFlowSegmentsApi.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/oneway_suspects/data/TrafficFlowSegmentsApi.kt
@@ -2,14 +2,20 @@ package de.westnordost.streetcomplete.quests.oneway_suspects.data
 
 import de.westnordost.streetcomplete.data.osm.mapdata.BoundingBox
 import de.westnordost.streetcomplete.util.ktx.format
+import io.ktor.client.HttpClient
+import io.ktor.client.call.body
+import io.ktor.client.plugins.expectSuccess
+import io.ktor.client.request.get
 import kotlinx.serialization.Serializable
 import kotlinx.serialization.json.Json
-import java.net.URL
 
-/** Dao for using this API: https://github.com/ENT8R/oneway-data-api  */
-class TrafficFlowSegmentsApi(private val apiUrl: String) {
+/** Dao for using this API: https://github.com/streetcomplete/oneway-data-api  */
+class TrafficFlowSegmentsApi(
+    private val httpClient: HttpClient,
+    private val apiUrl: String
+) {
 
-    fun get(bbox: BoundingBox): Map<Long, List<TrafficFlowSegment>> {
+    suspend fun get(bbox: BoundingBox): Map<Long, List<TrafficFlowSegment>> {
         val leftBottomRightTopString = listOf(
             bbox.min.longitude,
             bbox.min.latitude,
@@ -17,9 +23,10 @@ class TrafficFlowSegmentsApi(private val apiUrl: String) {
             bbox.max.latitude
         ).joinToString(",") { it.format(7) }
 
-        val url = URL("$apiUrl?bbox=$leftBottomRightTopString")
-        val json = url.openConnection().getInputStream().bufferedReader().use { it.readText() }
-        return parse(json)
+        val response = httpClient.get("$apiUrl?bbox=$leftBottomRightTopString") {
+            expectSuccess = true
+        }
+        return parse(response.body())
     }
 
     companion object {
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/oneway_suspects/data/TrafficFlowSegmentsModule.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/oneway_suspects/data/TrafficFlowSegmentsModule.kt
index 9c95113d3ad..c94536acdb5 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/quests/oneway_suspects/data/TrafficFlowSegmentsModule.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/oneway_suspects/data/TrafficFlowSegmentsModule.kt
@@ -4,5 +4,5 @@ import org.koin.dsl.module
 
 const val ONEWAY_API_URL = "https://www.westnordost.de/streetcomplete/oneway-data-api/"
 val trafficFlowSegmentsModule = module {
-    factory { TrafficFlowSegmentsApi(ONEWAY_API_URL) }
+    factory { TrafficFlowSegmentsApi(get(), ONEWAY_API_URL) }
 }
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/opening_hours_signed/CheckOpeningHoursSigned.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/opening_hours_signed/CheckOpeningHoursSigned.kt
index d7f7ec1a99f..6c6a17ec040 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/quests/opening_hours_signed/CheckOpeningHoursSigned.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/opening_hours_signed/CheckOpeningHoursSigned.kt
@@ -79,7 +79,7 @@ class CheckOpeningHoursSigned(
             }
         } else {
             tags["opening_hours:signed"] = "no"
-            /* still unsigned: just set the check date to now, user was on-site */
+            // still unsigned: just set the check date to now, user was on-site
             tags.updateCheckDateForKey("opening_hours")
         }
     }
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/religion/ReligionItem.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/religion/ReligionItem.kt
index ddd3ca367e4..d8ab3163c08 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/quests/religion/ReligionItem.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/religion/ReligionItem.kt
@@ -20,7 +20,7 @@ import de.westnordost.streetcomplete.view.image_select.Item
 
 fun Religion.asItem(): DisplayItem<Religion>? {
     val iconResId = iconResId ?: return null
-    val titleResId = titleResId  ?: return null
+    val titleResId = titleResId ?: return null
     return Item(this, iconResId, titleResId)
 }
 
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/smoking/SmokingAllowedForm.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/smoking/SmokingAllowedForm.kt
index 0d1bf436f9d..1157f96f7dc 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/quests/smoking/SmokingAllowedForm.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/smoking/SmokingAllowedForm.kt
@@ -18,7 +18,7 @@ class SmokingAllowedForm : AListQuestForm<SmokingAllowed>() {
         val noOutdoorSmoking =
             tags["outdoor_seating"] == "no" &&
             tags["amenity"] != "nightclub" && tags["amenity"] != "stripclub" && tags["amenity"] != "pub"
-            /* nightclubs etc. might have outside smoking areas even when there is no seating outside */
+            // nightclubs etc. might have outside smoking areas even when there is no seating outside
 
         return listOfNotNull(
             TextItem(NO, R.string.quest_smoking_no),
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/sport/AddSport.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/sport/AddSport.kt
index 832c4f85450..661a58b9e98 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/quests/sport/AddSport.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/sport/AddSport.kt
@@ -14,7 +14,7 @@ class AddSport : OsmFilterQuestType<List<Sport>>() {
           and (!sport or sport ~ football|skating|hockey|team_handball)
           and access !~ private|no
     """
-    /* treat ambiguous values as if it is not set */
+    // treat ambiguous values as if it is not set
     override val changesetComment = "Specify sport played on pitches"
     override val wikiLink = "Key:sport"
     override val icon = R.drawable.ic_quest_sport
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/surface/AddPathSurface.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/surface/AddPathSurface.kt
index 139c38967d9..e8058283aa8 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/quests/surface/AddPathSurface.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/surface/AddPathSurface.kt
@@ -36,7 +36,7 @@ class AddPathSurface : OsmFilterQuestType<SurfaceOrIsStepsAnswer>() {
         )
         and ~path|footway|cycleway|bridleway !~ link
     """
-    /* ~paved ways are less likely to change the surface type */
+    // ~paved ways are less likely to change the surface type
 
     override val changesetComment = "Specify path surfaces"
     override val wikiLink = "Key:surface"
diff --git a/app/src/main/java/de/westnordost/streetcomplete/quests/tracktype/AddTracktype.kt b/app/src/main/java/de/westnordost/streetcomplete/quests/tracktype/AddTracktype.kt
index 8db098d74d8..71f20db0507 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/quests/tracktype/AddTracktype.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/quests/tracktype/AddTracktype.kt
@@ -21,7 +21,7 @@ class AddTracktype : OsmFilterQuestType<Tracktype>() {
         )
         and (access !~ private|no or (foot and foot !~ private|no))
     """
-    /* ~paved tracks are less likely to change the surface type */
+    // ~paved tracks are less likely to change the surface type
     override val changesetComment = "Specify tracktypes"
     override val wikiLink = "Key:tracktype"
     override val icon = R.drawable.ic_quest_tractor
diff --git a/app/src/main/java/de/westnordost/streetcomplete/screens/about/LogsFiltersDialog.kt b/app/src/main/java/de/westnordost/streetcomplete/screens/about/LogsFiltersDialog.kt
index 81522a43c36..17519115767 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/screens/about/LogsFiltersDialog.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/screens/about/LogsFiltersDialog.kt
@@ -113,7 +113,7 @@ class LogsFiltersDialog(
 
     private fun updateNewerThanInput() {
         binding.newerThanEditTextLayout.isEndIconVisible = timestampNewerThan != null
-        binding.newerThanEditText.setText(timestampNewerThan?.let {  dateTimeToString(locale, it) } ?: "")
+        binding.newerThanEditText.setText(timestampNewerThan?.let { dateTimeToString(locale, it) } ?: "")
     }
 
     private fun updateOlderThanInput() {
diff --git a/app/src/main/java/de/westnordost/streetcomplete/screens/main/MainFragment.kt b/app/src/main/java/de/westnordost/streetcomplete/screens/main/MainFragment.kt
index ce22871037d..8bd9d6bf41d 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/screens/main/MainFragment.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/screens/main/MainFragment.kt
@@ -998,7 +998,7 @@ class MainFragment :
     }
 
     private fun onClickCompassButton() {
-        /* Clicking the compass button will always rotate the map back to north and remove tilt */
+        // Clicking the compass button will always rotate the map back to north and remove tilt
         val mapFragment = mapFragment ?: return
         val camera = mapFragment.cameraPosition ?: return
 
diff --git a/app/src/main/java/de/westnordost/streetcomplete/screens/main/bottom_sheet/CreateNoteFragment.kt b/app/src/main/java/de/westnordost/streetcomplete/screens/main/bottom_sheet/CreateNoteFragment.kt
index 744c035c2be..771d2347a94 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/screens/main/bottom_sheet/CreateNoteFragment.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/screens/main/bottom_sheet/CreateNoteFragment.kt
@@ -30,6 +30,7 @@ import de.westnordost.streetcomplete.quests.note_discussion.AttachPhotoFragment
 import de.westnordost.streetcomplete.util.ktx.childFragmentManagerOrNull
 import de.westnordost.streetcomplete.util.ktx.getLocationInWindow
 import de.westnordost.streetcomplete.util.ktx.hideKeyboard
+import de.westnordost.streetcomplete.util.ktx.isKeyboardOpen
 import de.westnordost.streetcomplete.util.ktx.viewLifecycleScope
 import de.westnordost.streetcomplete.util.dialogs.showOutsideDownloadedAreaDialog
 import de.westnordost.streetcomplete.util.viewBinding
@@ -159,7 +160,10 @@ class CreateNoteFragment : AbstractCreateNoteFragment() {
     override fun onComposedNote(text: String, imagePaths: List<String>, isGpxNote: Boolean) {
         /* pressing once on "OK" should first only close the keyboard, so that the user can review
            the position of the note he placed (this is now optional) */
-        if (prefs.getBoolean(Prefs.HIDE_KEYBOARD_FOR_NOTE, true) && contentBinding.noteInput.hideKeyboard() == true) return
+        if (prefs.getBoolean(Prefs.HIDE_KEYBOARD_FOR_NOTE, true) && contentBinding.noteInput.isKeyboardOpen) {
+            contentBinding.noteInput.hideKeyboard()
+            return
+        }
 
         val createNoteMarker = binding.markerCreateLayout.createNoteMarker
         val screenPos = createNoteMarker.getLocationInWindow()
diff --git a/app/src/main/java/de/westnordost/streetcomplete/screens/main/controls/UndoButtonFragment.kt b/app/src/main/java/de/westnordost/streetcomplete/screens/main/controls/UndoButtonFragment.kt
index ca28b30c657..ea28ecaa1d2 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/screens/main/controls/UndoButtonFragment.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/screens/main/controls/UndoButtonFragment.kt
@@ -31,7 +31,7 @@ class UndoButtonFragment : Fragment(R.layout.fragment_undo_button) {
     }
     private val listener: Listener? get() = parentFragment as? Listener ?: activity as? Listener
 
-    /* undo button is not shown when there is nothing to undo */
+    // undo button is not shown when there is nothing to undo
     private val editHistoryListener = object : EditHistorySource.Listener {
         override fun onAdded(edit: Edit) { viewLifecycleScope.launch { animateInIfAnythingToUndo() } }
         override fun onSynced(edit: Edit) { viewLifecycleScope.launch { animateOutIfNothingLeftToUndo() } }
diff --git a/app/src/main/java/de/westnordost/streetcomplete/screens/settings/DataManagementSettingsFragment.kt b/app/src/main/java/de/westnordost/streetcomplete/screens/settings/DataManagementSettingsFragment.kt
index 51d906b5c7d..24f4b3b2d31 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/screens/settings/DataManagementSettingsFragment.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/screens/settings/DataManagementSettingsFragment.kt
@@ -813,7 +813,7 @@ private const val REQUEST_CODE_TREES_EXPORT = 5332
 private const val REQUEST_CODE_CUSTOM_QUEST_IMPORT = 5333
 private const val REQUEST_CODE_CUSTOM_QUEST_EXPORT = 5334
 
-const val LAST_KNOWN_DB_VERSION = 15L
+const val LAST_KNOWN_DB_VERSION = 16L
 
 private const val BACKUP_HIDDEN_OSM_QUESTS = "quests"
 private const val BACKUP_HIDDEN_NOTES = "notes"
diff --git a/app/src/main/java/de/westnordost/streetcomplete/screens/settings/SettingsFragment.kt b/app/src/main/java/de/westnordost/streetcomplete/screens/settings/SettingsFragment.kt
index 0264feeec54..f52d571fb1f 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/screens/settings/SettingsFragment.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/screens/settings/SettingsFragment.kt
@@ -108,7 +108,7 @@ class SettingsFragment : TwoPaneListFragment(), HasTitle {
         override fun onUnhidAll() { setHiddenQuestsSummary() }
     }
 
-    private val onAutosyncChanged =  {
+    private val onAutosyncChanged = {
         if (Prefs.Autosync.valueOf(prefs.getStringOrNull(Prefs.AUTOSYNC) ?: "ON") != Prefs.Autosync.ON) {
             AlertDialog.Builder(requireContext())
                 .setView(layoutInflater.inflate(R.layout.dialog_tutorial_upload, null))
diff --git a/app/src/main/java/de/westnordost/streetcomplete/screens/user/login/OAuthFragment.kt b/app/src/main/java/de/westnordost/streetcomplete/screens/user/login/OAuthFragment.kt
index 8a85c6626ea..94524984c3a 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/screens/user/login/OAuthFragment.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/screens/user/login/OAuthFragment.kt
@@ -18,8 +18,10 @@ import de.westnordost.streetcomplete.data.user.OAUTH2_REDIRECT_URI
 import de.westnordost.streetcomplete.data.user.OAUTH2_REQUESTED_SCOPES
 import de.westnordost.streetcomplete.data.user.OAUTH2_REQUIRED_SCOPES
 import de.westnordost.streetcomplete.data.user.OAUTH2_TOKEN_URL
-import de.westnordost.streetcomplete.data.user.oauth.OAuthAuthorization
+import de.westnordost.streetcomplete.data.user.oauth.OAuthAuthorizationParams
 import de.westnordost.streetcomplete.data.user.oauth.OAuthException
+import de.westnordost.streetcomplete.data.user.oauth.OAuthService
+import de.westnordost.streetcomplete.data.user.oauth.extractAuthorizationCode
 import de.westnordost.streetcomplete.databinding.FragmentOauthBinding
 import de.westnordost.streetcomplete.screens.HasTitle
 import de.westnordost.streetcomplete.util.ktx.toast
@@ -31,8 +33,7 @@ import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import kotlinx.serialization.encodeToString
 import kotlinx.serialization.json.Json
-import java.net.URI
-import java.net.URISyntaxException
+import org.koin.android.ext.android.inject
 import java.util.Locale
 import kotlin.coroutines.Continuation
 import kotlin.coroutines.resumeWithException
@@ -49,8 +50,8 @@ class OAuthFragment : Fragment(R.layout.fragment_oauth), HasTitle {
     }
     private val listener: Listener? get() = parentFragment as? Listener ?: activity as? Listener
     private val webViewClient: OAuthWebViewClient = OAuthWebViewClient()
-
-    private lateinit var oAuth: OAuthAuthorization
+    private val oAuthService: OAuthService by inject()
+    private lateinit var oAuth: OAuthAuthorizationParams
 
     override val title: String get() = getString(R.string.user_login)
 
@@ -78,7 +79,7 @@ class OAuthFragment : Fragment(R.layout.fragment_oauth), HasTitle {
     override fun onCreate(inState: Bundle?) {
         super.onCreate(inState)
         oAuth = inState?.getString(OAUTH)?.let { Json.decodeFromString(it) }
-            ?: OAuthAuthorization(
+            ?: OAuthAuthorizationParams(
                 OAUTH2_AUTHORIZATION_URL,
                 OAUTH2_TOKEN_URL,
                 OAUTH2_CLIENT_ID,
@@ -113,7 +114,7 @@ class OAuthFragment : Fragment(R.layout.fragment_oauth), HasTitle {
         try {
             binding.webView.visibility = View.VISIBLE
             binding.webView.loadUrl(
-                oAuth.createAuthorizationUrl(),
+                oAuth.authorizationRequestUrl,
                 mutableMapOf("Accept-Language" to Locale.getDefault().toLanguageTag())
             )
             val authorizationCode = webViewClient.awaitOAuthCallback()
@@ -121,7 +122,7 @@ class OAuthFragment : Fragment(R.layout.fragment_oauth), HasTitle {
 
             binding.progressView.visibility = View.VISIBLE
             val accessTokenResponse = withContext(Dispatchers.IO) {
-                oAuth.retrieveAccessToken(authorizationCode)
+                oAuthService.retrieveAccessToken(oAuth, authorizationCode)
             }
             // not all requires scopes granted
             if (accessTokenResponse.grantedScopes?.containsAll(OAUTH2_REQUIRED_SCOPES) == false) {
@@ -159,13 +160,8 @@ class OAuthFragment : Fragment(R.layout.fragment_oauth), HasTitle {
 
         @Deprecated("Deprecated in Java")
         override fun shouldOverrideUrlLoading(view: WebView?, url: String): Boolean {
-            val uri = try {
-                URI(url)
-            } catch (e: URISyntaxException) {
-                return false
-            }
-            if (!oAuth.itsForMe(uri)) return false
-            continuation?.resumeWith(runCatching { oAuth.extractAuthorizationCode(uri) })
+            if (!oAuth.itsForMe(url)) return false
+            continuation?.resumeWith(runCatching { extractAuthorizationCode(url) })
             return true
         }
 
diff --git a/app/src/main/java/de/westnordost/streetcomplete/screens/user/profile/ProfileFragment.kt b/app/src/main/java/de/westnordost/streetcomplete/screens/user/profile/ProfileFragment.kt
index 299ffe0ead3..deecea3e433 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/screens/user/profile/ProfileFragment.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/screens/user/profile/ProfileFragment.kt
@@ -71,7 +71,7 @@ class ProfileFragment : Fragment(R.layout.fragment_profile) {
             viewLifecycleScope.launch { updateEditCountTexts() }
         }
         override fun onSubtractedOne(type: String) {
-            viewLifecycleScope.launch { updateEditCountTexts()  }
+            viewLifecycleScope.launch { updateEditCountTexts() }
         }
         override fun onUpdatedAll() {
             viewLifecycleScope.launch { updateStatisticsTexts() }
diff --git a/app/src/main/java/de/westnordost/streetcomplete/screens/user/statistics/CircularFlagView.kt b/app/src/main/java/de/westnordost/streetcomplete/screens/user/statistics/CircularFlagView.kt
index 844e526fd57..3a2242f2422 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/screens/user/statistics/CircularFlagView.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/screens/user/statistics/CircularFlagView.kt
@@ -63,7 +63,7 @@ class CircularFlagView @JvmOverloads constructor(
     }
 
     override fun setRotation(rotation: Float) {
-        /* this view can't handle rotation properly */
+        // this view can't handle rotation properly
     }
 
     override fun onDraw(canvas: Canvas) {
@@ -137,7 +137,7 @@ class CircularFlagView @JvmOverloads constructor(
     }
 
     companion object {
-        /* make sure the YAML is only read once and kept once for all instances of SquareFlagView*/
+        // make sure the YAML is only read once and kept once for all instances of SquareFlagView
         private var map: Map<String, FlagAlignment>? = null
 
         private fun get(resources: Resources, countryCode: String): FlagAlignment? {
diff --git a/app/src/main/java/de/westnordost/streetcomplete/util/ktx/Context.kt b/app/src/main/java/de/westnordost/streetcomplete/util/ktx/Context.kt
index de592c67086..a65b44e6539 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/util/ktx/Context.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/util/ktx/Context.kt
@@ -8,9 +8,6 @@ import android.content.Intent
 import android.content.IntentFilter
 import android.content.pm.PackageManager
 import android.location.LocationManager
-import android.view.View
-import android.view.inputmethod.InputMethodManager
-import android.view.inputmethod.InputMethodManager.SHOW_IMPLICIT
 import android.widget.Toast
 import androidx.annotation.StringRes
 import androidx.core.content.ContextCompat
@@ -51,16 +48,9 @@ fun Context.toast(@StringRes resId: Int, duration: Int = Toast.LENGTH_SHORT) {
 fun Context.hasPermission(permission: String): Boolean =
     ContextCompat.checkSelfPermission(this, permission) == PackageManager.PERMISSION_GRANTED
 
-fun View.showKeyboard(): Boolean? =
-    context?.inputMethodManager?.showSoftInput(this, SHOW_IMPLICIT)
-
-fun View.hideKeyboard(): Boolean? =
-    context?.inputMethodManager?.hideSoftInputFromWindow(windowToken, 0)
-
 val Context.isLocationEnabled: Boolean get() = LocationManagerCompat.isLocationEnabled(locationManager)
 val Context.hasLocationPermission: Boolean get() = hasPermission(ACCESS_FINE_LOCATION)
 
-private val Context.inputMethodManager get() = getSystemService<InputMethodManager>()!!
 private val Context.locationManager get() = getSystemService<LocationManager>()!!
 
 /** Await a call from a broadcast once and return it */
diff --git a/app/src/main/java/de/westnordost/streetcomplete/util/ktx/Location.kt b/app/src/main/java/de/westnordost/streetcomplete/util/ktx/Location.kt
index 573d9882026..ea91c4ed771 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/util/ktx/Location.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/util/ktx/Location.kt
@@ -2,5 +2,9 @@ package de.westnordost.streetcomplete.util.ktx
 
 import android.location.Location
 import de.westnordost.streetcomplete.data.osm.mapdata.LatLon
+import kotlin.time.Duration
+import kotlin.time.Duration.Companion.nanoseconds
 
 fun Location.toLatLon() = LatLon(latitude, longitude)
+
+val Location.elapsedDuration: Duration get() = elapsedRealtimeNanos.nanoseconds
diff --git a/app/src/main/java/de/westnordost/streetcomplete/util/ktx/URL.kt b/app/src/main/java/de/westnordost/streetcomplete/util/ktx/URL.kt
deleted file mode 100644
index 40750ce39ab..00000000000
--- a/app/src/main/java/de/westnordost/streetcomplete/util/ktx/URL.kt
+++ /dev/null
@@ -1,12 +0,0 @@
-package de.westnordost.streetcomplete.util.ktx
-
-import java.io.File
-import java.net.URL
-
-fun URL.saveToFile(file: File) {
-    openStream().use { input ->
-        file.outputStream().use { output ->
-            input.copyTo(output)
-        }
-    }
-}
diff --git a/app/src/main/java/de/westnordost/streetcomplete/util/ktx/View.kt b/app/src/main/java/de/westnordost/streetcomplete/util/ktx/View.kt
index 2c3cb5c9417..1aa60ca45e9 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/util/ktx/View.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/util/ktx/View.kt
@@ -9,6 +9,9 @@ import android.view.animation.AccelerateInterpolator
 import android.view.animation.DecelerateInterpolator
 import androidx.core.graphics.Insets
 import androidx.core.os.postDelayed
+import androidx.core.view.SoftwareKeyboardControllerCompat
+import androidx.core.view.ViewCompat
+import androidx.core.view.WindowInsetsCompat
 import androidx.core.view.doOnPreDraw
 import androidx.core.view.updateLayoutParams
 import kotlinx.coroutines.suspendCancellableCoroutine
@@ -95,3 +98,10 @@ fun View.updateMargins(left: Int? = null, top: Int? = null, right: Int? = null,
         )
     }
 }
+
+fun View.showKeyboard(): Unit = SoftwareKeyboardControllerCompat(this).show()
+
+fun View.hideKeyboard(): Unit = SoftwareKeyboardControllerCompat(this).hide()
+
+val View.isKeyboardOpen: Boolean
+    get() = ViewCompat.getRootWindowInsets(this)?.isVisible(WindowInsetsCompat.Type.ime()) == true
diff --git a/app/src/main/java/de/westnordost/streetcomplete/util/location/FineLocationManager.kt b/app/src/main/java/de/westnordost/streetcomplete/util/location/FineLocationManager.kt
index e1314ccdd3b..c6d2a208f8e 100644
--- a/app/src/main/java/de/westnordost/streetcomplete/util/location/FineLocationManager.kt
+++ b/app/src/main/java/de/westnordost/streetcomplete/util/location/FineLocationManager.kt
@@ -15,6 +15,8 @@ import androidx.core.location.LocationListenerCompat
 import androidx.core.location.LocationManagerCompat
 import androidx.core.os.CancellationSignal
 import androidx.core.util.Consumer
+import de.westnordost.streetcomplete.util.ktx.elapsedDuration
+import kotlin.time.Duration.Companion.nanoseconds
 
 /** Convenience wrapper around the location manager with easier API, making use of both the GPS
  *  and Network provider */
@@ -69,13 +71,13 @@ class FineLocationManager(context: Context, locationUpdateCallback: (Location) -
     fun getLastLocation() : Location? {
         if (deviceHasGPS) {
             locationManager.getLastKnownLocation(GPS_PROVIDER)?.let {
-                if (it.elapsedRealtimeNanos > SystemClock.elapsedRealtimeNanos() - TWO_MINUTES_IN_NANOSECONDS)
+                if ((SystemClock.elapsedRealtimeNanos().nanoseconds - it.elapsedDuration).inWholeMinutes < 2)
                     return it
             }
         }
         if (deviceHasNetworkLocationProvider) {
             locationManager.getLastKnownLocation(NETWORK_PROVIDER)?.let {
-                if (it.elapsedRealtimeNanos > SystemClock.elapsedRealtimeNanos() - TWO_MINUTES_IN_NANOSECONDS)
+                if ((SystemClock.elapsedRealtimeNanos().nanoseconds - it.elapsedDuration).inWholeMinutes < 2)
                     return it
             }
         }
@@ -106,13 +108,11 @@ class FineLocationManager(context: Context, locationUpdateCallback: (Location) -
 
 // Based on https://web.archive.org/web/20180424190538/https://developer.android.com/guide/topics/location/strategies.html#BestEstimate
 
-private const val TWO_MINUTES_IN_NANOSECONDS = 1000L * 1000 * 1000 * 60 * 2
-
 /** Determines whether this Location reading is better than the previous Location fix */
 private fun Location.isBetterThan(previous: Location?): Boolean {
     // Check whether this is a valid location at all.
     // Happened once that lat/lon is NaN, maybe issue of that particular device
-    if (this.longitude.isNaN() || this.latitude.isNaN()) return false
+    if (longitude.isNaN() || latitude.isNaN()) return false
 
     // A new location is always better than no location
     if (previous == null) return true
@@ -120,20 +120,18 @@ private fun Location.isBetterThan(previous: Location?): Boolean {
     // Check whether the new location fix is newer or older
     // we use elapsedRealtimeNanos instead of epoch time because some devices have issues
     // that may lead to incorrect GPS location.time (e.g. GPS week rollover, but also others)
-    // the use of nanoseconds is necessary because it is the only way to get
-    // elapsedRealtime of a location before API level 33
-    val timeDelta = this.elapsedRealtimeNanos - previous.elapsedRealtimeNanos
-    val isMuchNewer = timeDelta > TWO_MINUTES_IN_NANOSECONDS
-    val isMuchOlder = timeDelta < -TWO_MINUTES_IN_NANOSECONDS
-    val isNewer = timeDelta > 0L
+    val diffMinutes = (elapsedDuration - previous.elapsedDuration).inWholeMinutes
+    val isMuchNewer = diffMinutes > 2
+    val isMuchOlder = diffMinutes < -2
+    val isNewer = diffMinutes > 0
 
     // Check whether the new location fix is more or less accurate
-    val accuracyDelta = this.accuracy - previous.accuracy
+    val accuracyDelta = accuracy - previous.accuracy
     val isLessAccurate = accuracyDelta > 0f
     val isMoreAccurate = accuracyDelta < 0f
     val isMuchLessAccurate = accuracyDelta > 200f
 
-    val isFromSameProvider = this.provider == previous.provider
+    val isFromSameProvider = provider == previous.provider
 
     // Determine location quality using a combination of timeliness and accuracy
     return when {
diff --git a/app/src/main/res/layout/fragment_overlay.xml b/app/src/main/res/layout/fragment_overlay.xml
index 3508afe7086..497a65bc360 100644
--- a/app/src/main/res/layout/fragment_overlay.xml
+++ b/app/src/main/res/layout/fragment_overlay.xml
@@ -149,6 +149,7 @@
             android:id="@+id/glassPane"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
+            android:elevation="@dimen/speech_bubble_elevation"
             android:clickable="true"
             android:focusable="true"
             android:visibility="gone"
diff --git a/app/src/main/res/layout/fragment_quest_answer.xml b/app/src/main/res/layout/fragment_quest_answer.xml
index 19253393b45..12da540dd53 100644
--- a/app/src/main/res/layout/fragment_quest_answer.xml
+++ b/app/src/main/res/layout/fragment_quest_answer.xml
@@ -200,6 +200,7 @@
         android:id="@+id/glassPane"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
+        android:elevation="@dimen/speech_bubble_elevation"
         android:clickable="true"
         android:focusable="true"
         android:visibility="gone"
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index ce5da194c43..6e09741e606 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -1102,6 +1102,7 @@ If any lanes are reserved for buses, please leave a note instead."</string>
     <string name="quest_leaf_type_needles">Needles</string>
     <string name="quest_leaf_type_broadleaved">Leaves</string>
     <string name="quest_leaf_type_mixed">Both are present</string>
+    <string name="quest_leafType_tree_title">Does this tree have needles or leaves?</string>
 
     <string name="quest_level_title2">On which level number is this place located?</string>
 
diff --git a/app/src/test/java/de/westnordost/streetcomplete/OpeningHoursParsingTest.kt b/app/src/test/java/de/westnordost/streetcomplete/OpeningHoursParsingTest.kt
index 7b4829e8bbb..0cb715224eb 100644
--- a/app/src/test/java/de/westnordost/streetcomplete/OpeningHoursParsingTest.kt
+++ b/app/src/test/java/de/westnordost/streetcomplete/OpeningHoursParsingTest.kt
@@ -186,7 +186,7 @@ private fun TimesSelector.hasVariableTime(): Boolean = when (this) {
 
 private fun MonthsOrDateSelector.hasYear(): Boolean = when (this) {
     is Date -> hasYear()
-    is DateRange -> start.hasYear()  || end.hasYear()
+    is DateRange -> start.hasYear() || end.hasYear()
     is DatesInMonth -> year != null
     is MonthRange -> year != null
     is SingleMonth -> year != null
diff --git a/app/src/test/java/de/westnordost/streetcomplete/data/osmnotes/AvatarsDownloaderTest.kt b/app/src/test/java/de/westnordost/streetcomplete/data/osmnotes/AvatarsDownloaderTest.kt
new file mode 100644
index 00000000000..6e142befafe
--- /dev/null
+++ b/app/src/test/java/de/westnordost/streetcomplete/data/osmnotes/AvatarsDownloaderTest.kt
@@ -0,0 +1,78 @@
+package de.westnordost.streetcomplete.data.osmnotes
+
+import de.westnordost.osmapi.user.UserApi
+import de.westnordost.osmapi.user.UserInfo
+import de.westnordost.streetcomplete.testutils.mock
+import de.westnordost.streetcomplete.testutils.on
+import io.ktor.client.HttpClient
+import io.ktor.client.engine.mock.MockEngine
+import io.ktor.client.engine.mock.respondError
+import io.ktor.client.engine.mock.respondOk
+import io.ktor.http.HttpMethod
+import io.ktor.http.HttpStatusCode
+import io.ktor.utils.io.errors.IOException
+import kotlinx.coroutines.runBlocking
+import java.nio.file.Files
+import kotlin.test.BeforeTest
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class AvatarsDownloaderTest {
+    private val mockEngine = MockEngine { request -> when (request.url.encodedPath) {
+        "/NotFound" -> respondError(HttpStatusCode.NotFound)
+        "/ConnectionError" -> throw IOException("Cannot connect")
+        else -> respondOk("Image Content")
+    } }
+    private val tempFolder = Files.createTempDirectory("images").toFile()
+    private val userApi: UserApi = mock()
+    private val downloader = AvatarsDownloader(HttpClient(mockEngine), userApi, tempFolder)
+    private val userInfo = UserInfo(100, "Map Enthusiast 530")
+
+    @BeforeTest fun setUp() {
+        userInfo.profileImageUrl = "http://example.com/BigImage.png"
+        on(userApi.get(userInfo.id)).thenReturn(userInfo)
+    }
+
+    @Test
+    fun `download makes GET request to profileImageUrl`() = runBlocking {
+        downloader.download(listOf(userInfo.id))
+
+        assertEquals(1, mockEngine.requestHistory.size)
+        assertEquals(userInfo.profileImageUrl, mockEngine.requestHistory[0].url.toString())
+        assertEquals(HttpMethod.Get, mockEngine.requestHistory[0].method)
+    }
+
+    @Test
+    fun `download copies HTTP response from profileImageUrl into tempFolder`() = runBlocking {
+        downloader.download(listOf(userInfo.id))
+
+        assertEquals("Image Content", tempFolder.resolve("100").readText())
+    }
+
+    @Test
+    fun `download does not throw exception on HTTP NotFound`() = runBlocking {
+        userInfo.profileImageUrl = "http://example.com/NotFound"
+
+        downloader.download(listOf(userInfo.id))
+
+        assertEquals(404, mockEngine.responseHistory[0].statusCode.value)
+    }
+
+    @Test
+    fun `download does not throw exception on networking error`() = runBlocking {
+        userInfo.profileImageUrl = "http://example.com/ConnectionError"
+
+        downloader.download(listOf(userInfo.id))
+
+        assertEquals(0, mockEngine.responseHistory.size)
+    }
+
+    @Test
+    fun `download does not make HTTP request if profileImageUrl is NULL`() = runBlocking {
+        userInfo.profileImageUrl = null
+
+        downloader.download(listOf(userInfo.id))
+
+        assertEquals(0, mockEngine.requestHistory.size)
+    }
+}
diff --git a/app/src/test/java/de/westnordost/streetcomplete/data/osmnotes/StreetCompleteImageUploaderTest.kt b/app/src/test/java/de/westnordost/streetcomplete/data/osmnotes/StreetCompleteImageUploaderTest.kt
new file mode 100644
index 00000000000..630ea8814de
--- /dev/null
+++ b/app/src/test/java/de/westnordost/streetcomplete/data/osmnotes/StreetCompleteImageUploaderTest.kt
@@ -0,0 +1,121 @@
+package de.westnordost.streetcomplete.data.osmnotes
+
+import de.westnordost.streetcomplete.data.download.ConnectionException
+import io.ktor.client.HttpClient
+import io.ktor.client.engine.mock.MockEngine
+import io.ktor.client.engine.mock.respondBadRequest
+import io.ktor.client.engine.mock.respondError
+import io.ktor.client.engine.mock.respondOk
+import io.ktor.client.engine.mock.toByteArray
+import io.ktor.http.ContentType
+import io.ktor.http.HttpMethod
+import io.ktor.http.HttpStatusCode
+import io.ktor.utils.io.errors.IOException
+import kotlinx.coroutines.runBlocking
+import kotlin.test.Test
+import kotlin.test.assertContentEquals
+import kotlin.test.assertEquals
+import kotlin.test.assertFailsWith
+
+class StreetCompleteImageUploaderTest {
+    private val mockEngine = MockEngine { request -> when (String(request.body.toByteArray())) {
+        // Upload requests
+        "valid\n" -> respondOk("{\"future_url\": \"market.jpg\"}")
+        "invalid\n" -> respondError(HttpStatusCode.InternalServerError)
+        "" -> respondBadRequest()
+        "ioexception\n" -> throw IOException("Unable to connect")
+
+        // Activate requests
+        "{\"osm_note_id\": 180}" -> respondOk()
+        "{\"osm_note_id\": 190}" -> respondError(HttpStatusCode.InternalServerError)
+        "{\"osm_note_id\": 200}" -> respondBadRequest()
+        "{\"osm_note_id\": 210}" -> throw IOException("Unable to connect")
+
+        else -> throw Exception("Invalid request body")
+    } }
+    private val uploader = StreetCompleteImageUploader(HttpClient(mockEngine), "http://example.com/" )
+
+    @Test
+    fun `upload makes POST request with file contents`() = runBlocking {
+        uploader.upload(listOf("src/test/resources/image_uploader/valid.jpg"))
+
+        assertEquals(1, mockEngine.requestHistory.size)
+        assertEquals(HttpMethod.Post, mockEngine.requestHistory[0].method)
+        assertEquals("http://example.com/upload.php", mockEngine.requestHistory[0].url.toString())
+        assertEquals(ContentType.Image.JPEG, mockEngine.requestHistory[0].body.contentType)
+        assertEquals("binary", mockEngine.requestHistory[0].headers["Content-Transfer-Encoding"])
+    }
+
+    @Test
+    fun `upload returns future_url value from response`() = runBlocking {
+        val uploads = uploader.upload(listOf("src/test/resources/image_uploader/valid.jpg"))
+
+        assertContentEquals(listOf("market.jpg"), uploads)
+    }
+
+    @Test
+    fun `upload throws ImageUploadServerException on 500 error`() = runBlocking {
+        val exception = assertFailsWith(ImageUploadServerException::class) {
+            uploader.upload(listOf("src/test/resources/image_uploader/invalid.jpg"))
+        }
+
+        assertEquals("Upload failed: Error code 500 Internal Server Error, Message: \"Internal Server Error\"", exception.message)
+    }
+
+    @Test
+    fun `upload throws ImageUploadClientException on 400 error`() = runBlocking {
+        val exception = assertFailsWith(ImageUploadClientException::class) {
+            uploader.upload(listOf("src/test/resources/image_uploader/empty.jpg"))
+        }
+
+        assertEquals("Upload failed: Error code 400 Bad Request, Message: \"Bad Request\"", exception.message)
+    }
+
+    @Test
+    fun `upload performs no requests with missing file`() = runBlocking {
+        assertContentEquals(listOf(), uploader.upload(listOf("no-such-file-at-this-path.jpg")))
+        assertEquals(0, mockEngine.requestHistory.size)
+    }
+
+    @Test
+    fun `upload throws ConnectionException on IOException`(): Unit = runBlocking {
+        assertFailsWith(ConnectionException::class) {
+            uploader.upload(listOf("src/test/resources/image_uploader/ioexception.jpg"))
+        }
+    }
+
+    @Test
+    fun `activate makes POST request with note ID`() = runBlocking {
+        uploader.activate(180)
+
+        assertEquals(1, mockEngine.requestHistory.size)
+        assertEquals("http://example.com/activate.php", mockEngine.requestHistory[0].url.toString())
+        assertEquals(ContentType.Application.Json, mockEngine.requestHistory[0].body.contentType)
+        assertEquals("{\"osm_note_id\": 180}", String(mockEngine.requestHistory[0].body.toByteArray()))
+    }
+
+    @Test
+    fun `activate throws ImageUploadServerException on 500 error`() = runBlocking {
+        val exception = assertFailsWith(ImageUploadServerException::class) {
+            uploader.activate(190)
+        }
+
+        assertEquals("Error code 500 Internal Server Error, Message: \"Internal Server Error\"", exception.message)
+    }
+
+    @Test
+    fun `activate throws ImageUploadClientException on 400 error`() = runBlocking {
+        val exception = assertFailsWith(ImageUploadClientException::class) {
+            uploader.activate(200)
+        }
+
+        assertEquals("Error code 400 Bad Request, Message: \"Bad Request\"", exception.message)
+    }
+
+    @Test
+    fun `activate throws ConnectionException on IOException`(): Unit = runBlocking {
+        assertFailsWith(ConnectionException::class) {
+            uploader.activate(210)
+        }
+    }
+}
diff --git a/app/src/test/java/de/westnordost/streetcomplete/data/osmnotes/edits/NoteEditsUploaderTest.kt b/app/src/test/java/de/westnordost/streetcomplete/data/osmnotes/edits/NoteEditsUploaderTest.kt
index a9bff060c72..6f0bb85ddcd 100644
--- a/app/src/test/java/de/westnordost/streetcomplete/data/osmnotes/edits/NoteEditsUploaderTest.kt
+++ b/app/src/test/java/de/westnordost/streetcomplete/data/osmnotes/edits/NoteEditsUploaderTest.kt
@@ -1,8 +1,10 @@
 package de.westnordost.streetcomplete.data.osmnotes.edits
 
+import de.westnordost.streetcomplete.data.osm.mapdata.LatLon
 import de.westnordost.streetcomplete.data.osmnotes.NoteController
 import de.westnordost.streetcomplete.data.osmnotes.NotesApi
 import de.westnordost.streetcomplete.data.osmnotes.StreetCompleteImageUploader
+import de.westnordost.streetcomplete.data.osmtracks.Trackpoint
 import de.westnordost.streetcomplete.data.osmtracks.TracksApi
 import de.westnordost.streetcomplete.data.upload.ConflictException
 import de.westnordost.streetcomplete.data.upload.OnUploadedChangeListener
@@ -143,7 +145,7 @@ class NoteEditsUploaderTest {
         verify(listener, times(2))!!.onUploaded(any(), any())
     }
 
-    @Test fun `upload note comment with attached images`() {
+    @Test fun `upload note comment with attached images`() = runBlocking {
         val pos = p(1.0, 13.0)
         val edit = noteEdit(
             noteId = 1L,
@@ -169,7 +171,7 @@ class NoteEditsUploaderTest {
         verify(listener)!!.onUploaded("NOTE", pos)
     }
 
-    @Test fun `upload create note with attached images`() {
+    @Test fun `upload create note with attached images`() = runBlocking {
         val pos = p(1.0, 13.0)
         val edit = noteEdit(
             noteId = 1L,
@@ -195,7 +197,31 @@ class NoteEditsUploaderTest {
         verify(listener)!!.onUploaded("NOTE", pos)
     }
 
-    @Test fun `upload missed image activations`() {
+    @Test fun `upload create note with attached GPS trace`() = runBlocking {
+        val pos = p(1.0, 13.0)
+        val edit = noteEdit(
+            noteId = 1L,
+            action = NoteEditAction.CREATE,
+            text = "test",
+            pos = pos,
+            track = listOf(Trackpoint(LatLon(0.0, 0.0), 180, 0.0f, 100.0f))
+        )
+        val note = note(1)
+
+        on(noteEditsController.getOldestUnsynced()).thenReturn(edit).thenReturn(null)
+        on(userDataSource.userName).thenReturn("blah mc/Blah")
+        on(notesApi.create(any(), any())).thenReturn(note)
+        on(tracksApi.create(edit.track, edit.text)).thenReturn(988)
+
+        upload()
+
+        verify(notesApi).create(pos, "test\n\nGPS Trace: https://www.openstreetmap.org/user/blah%20mc%2FBlah/traces/988\n")
+        verify(noteController).put(note)
+        verify(noteEditsController).markSynced(edit, note)
+        verify(listener)!!.onUploaded("NOTE", pos)
+    }
+
+    @Test fun `upload missed image activations`(): Unit = runBlocking {
         val edit = noteEdit(noteId = 3)
 
         on(noteEditsController.getOldestNeedingImagesActivation()).thenReturn(edit).thenReturn(null)
diff --git a/app/src/test/java/de/westnordost/streetcomplete/data/upload/VersionIsBannedCheckerTest.kt b/app/src/test/java/de/westnordost/streetcomplete/data/upload/VersionIsBannedCheckerTest.kt
index e5199732042..ab9ac07172c 100644
--- a/app/src/test/java/de/westnordost/streetcomplete/data/upload/VersionIsBannedCheckerTest.kt
+++ b/app/src/test/java/de/westnordost/streetcomplete/data/upload/VersionIsBannedCheckerTest.kt
@@ -1,21 +1,25 @@
 package de.westnordost.streetcomplete.data.upload
 
+import io.ktor.client.HttpClient
+import kotlinx.coroutines.runBlocking
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
 class VersionIsBannedCheckerTest {
-    @Test fun `banned version `() {
-        assertEquals(IsBanned(null), VersionIsBannedChecker(URL, "StreetComplete 0.1").get())
+    private val httpClient = HttpClient()
+
+    @Test fun `banned version `() = runBlocking {
+        assertEquals(IsBanned(null), VersionIsBannedChecker(httpClient, URL, "StreetComplete 0.1").get())
     }
 
-    @Test fun `not banned version `() {
-        assertEquals(IsNotBanned, VersionIsBannedChecker(URL, "StreetComplete 3.0").get())
+    @Test fun `not banned version `() = runBlocking {
+        assertEquals(IsNotBanned, VersionIsBannedChecker(httpClient, URL, "StreetComplete 3.0").get())
     }
 
-    @Test fun `banned version with reason`() {
+    @Test fun `banned version with reason`() = runBlocking {
         assertEquals(
             IsBanned("This version does not correctly determine in which country you are, necessary to tag certain answers correctly."),
-            VersionIsBannedChecker(URL, "StreetComplete 8.0").get()
+            VersionIsBannedChecker(httpClient, URL, "StreetComplete 8.0").get()
         )
     }
 }
diff --git a/app/src/test/java/de/westnordost/streetcomplete/data/user/oauth/OAuthAuthorizationTest.kt b/app/src/test/java/de/westnordost/streetcomplete/data/user/oauth/OAuthAuthorizationTest.kt
index b92ca703643..243ea1c5674 100644
--- a/app/src/test/java/de/westnordost/streetcomplete/data/user/oauth/OAuthAuthorizationTest.kt
+++ b/app/src/test/java/de/westnordost/streetcomplete/data/user/oauth/OAuthAuthorizationTest.kt
@@ -1,50 +1,55 @@
 package de.westnordost.streetcomplete.data.user.oauth
 
+import io.ktor.client.HttpClient
+import io.ktor.client.engine.mock.MockEngine
+import io.ktor.client.engine.mock.respondError
+import io.ktor.client.engine.mock.respondOk
+import io.ktor.http.HeadersBuilder
+import io.ktor.http.HttpStatusCode
+import io.ktor.http.ParametersBuilder
+import io.ktor.http.Url
+import kotlinx.coroutines.runBlocking
 import kotlinx.serialization.encodeToString
 import kotlinx.serialization.json.Json
-import java.net.URI
-import java.net.URL
-import java.net.URLDecoder
-import java.net.URLEncoder
 import kotlin.test.Test
 import kotlin.test.assertEquals
+import kotlin.test.assertFails
 import kotlin.test.assertFailsWith
 import kotlin.test.assertFalse
 import kotlin.test.assertTrue
 
 class OAuthAuthorizationTest {
     @Test fun createAuthorizationUrl() {
-        val url = URL(createOAuth().createAuthorizationUrl())
+        val url = Url(createOAuth().authorizationRequestUrl)
 
-        assertEquals("https", url.protocol)
+        assertEquals("https", url.protocol.name)
         assertEquals("test.me", url.host)
-        assertEquals("/auth", url.path)
-
-        val parameters = url.queryParameters
-        assertEquals("code", parameters["response_type"])
-        assertEquals("ClientId %#+!", parameters["client_id"])
-        assertEquals("localhost://oauth", parameters["redirect_uri"])
-        assertEquals("one! 2 THREE+(1/2)", parameters["scope"])
-        assertEquals("S256", parameters["code_challenge_method"])
-        assertTrue(parameters["code_challenge"]!!.length <= 128)
-        assertTrue(parameters["code_challenge"]!!.length >= 43)
+        assertEquals("/auth", url.encodedPath)
+
+        assertEquals("code", url.parameters["response_type"])
+        assertEquals("ClientId %#+!", url.parameters["client_id"])
+        assertEquals("localhost://oauth", url.parameters["redirect_uri"])
+        assertEquals("one! 2 THREE+(1/2)", url.parameters["scope"])
+        assertEquals("S256", url.parameters["code_challenge_method"])
+        assertTrue(url.parameters["code_challenge"]!!.length <= 128)
+        assertTrue(url.parameters["code_challenge"]!!.length >= 43)
     }
 
     @Test fun `createAuthorizationUrl with state`() {
-        val parameters = URL(createOAuth("123").createAuthorizationUrl()).queryParameters
+        val parameters = Url(createOAuth("123").authorizationRequestUrl).parameters
         assertEquals("123", parameters["state"])
     }
 
     @Test fun `generates different code challenge for each instance`() {
-        val url1 = URL(createOAuth().createAuthorizationUrl())
-        val url2 = URL(createOAuth().createAuthorizationUrl())
-        assertTrue(url1.queryParameters["code_challenge"] != url2.queryParameters["code_challenge"])
+        val url1 = Url(createOAuth().authorizationRequestUrl)
+        val url2 = Url(createOAuth().authorizationRequestUrl)
+        assertTrue(url1.parameters["code_challenge"] != url2.parameters["code_challenge"])
     }
 
     @Test fun `serializes correctly`() {
         val oauth1 = createOAuth()
         val oauth1String = Json.encodeToString(oauth1)
-        val oauth2 = Json.decodeFromString<OAuthAuthorization>(oauth1String)
+        val oauth2 = Json.decodeFromString<OAuthAuthorizationParams>(oauth1String)
         val oauth2String = Json.encodeToString(oauth2)
 
         assertEquals(oauth1String, oauth2String)
@@ -54,54 +59,53 @@ class OAuthAuthorizationTest {
         val state = "123"
         val oauth = createOAuth(state)
 
-        assertFalse(oauth.itsForMe(URI("localhost://oauth"))) // no state
-        assertFalse(oauth.itsForMe(URI("localhost://oauth?state=abc"))) // different state
-        assertTrue(oauth.itsForMe(URI("localhost://oauth?state=$state"))) // same state
+        assertFalse(oauth.itsForMe("This isn't::::a valid URL"))
+        assertFalse(oauth.itsForMe("localhost://oauth")) // no state
+        assertFalse(oauth.itsForMe("localhost://oauth?state=abc")) // different state
+        assertTrue(oauth.itsForMe("localhost://oauth?state=$state")) // same state
         // different uri
-        assertFalse(oauth.itsForMe(URI("localhost://oauth3?state=$state")))
-        assertFalse(oauth.itsForMe(URI("localhost://oauth/path?state=$state")))
-        assertFalse(oauth.itsForMe(URI("localboost://oauth?state=$state")))
+        assertFalse(oauth.itsForMe("localhost://oauth3?state=$state"))
+        assertFalse(oauth.itsForMe("localhost://oauth/path?state=$state"))
+        assertFalse(oauth.itsForMe("localboost://oauth?state=$state"))
     }
 
     @Test fun `itsForMe without state`() {
         val oauth = createOAuth()
 
-        assertTrue(oauth.itsForMe(URI("localhost://oauth"))) // no state
-        assertFalse(oauth.itsForMe(URI("localhost://oauth?state=abc"))) // different state
+        assertTrue(oauth.itsForMe("localhost://oauth")) // no state
+        assertFalse(oauth.itsForMe("localhost://oauth?state=abc")) // different state
         // different uri
-        assertFalse(oauth.itsForMe(URI("localhost://oauth3")))
-        assertFalse(oauth.itsForMe(URI("localhost://oauth/path")))
-        assertFalse(oauth.itsForMe(URI("localboost://oauth")))
+        assertFalse(oauth.itsForMe("localhost://oauth3"))
+        assertFalse(oauth.itsForMe("localhost://oauth/path"))
+        assertFalse(oauth.itsForMe("localboost://oauth"))
     }
 
     @Test fun `extractAuthorizationCode fails with useful error messages`() {
-        val oauth = createOAuth()
-
         // server did not respond correctly with "error"
         assertFailsWith<OAuthConnectionException> {
-            oauth.extractAuthorizationCode(URI("localhost://oauth?e=something"))
+            extractAuthorizationCode("localhost://oauth?e=something")
         }
 
         try {
-            oauth.extractAuthorizationCode(URI("localhost://oauth?error=hey%2Bwhat%27s%2Bup"))
+            extractAuthorizationCode("localhost://oauth?error=hey%2Bwhat%27s%2Bup")
         } catch (e: OAuthException) {
             assertEquals("hey what's up", e.message)
         }
 
         try {
-            oauth.extractAuthorizationCode(URI("localhost://oauth?error=A%21&error_description=B%21"))
+            extractAuthorizationCode("localhost://oauth?error=A%21&error_description=B%21")
         } catch (e: OAuthException) {
             assertEquals("A!: B!", e.message)
         }
 
         try {
-            oauth.extractAuthorizationCode(URI("localhost://oauth?error=A%21&error_uri=http%3A%2F%2Fabc.de"))
+            extractAuthorizationCode("localhost://oauth?error=A%21&error_uri=http%3A%2F%2Fabc.de")
         } catch (e: OAuthException) {
             assertEquals("A! (see http://abc.de)", e.message)
         }
 
         try {
-            oauth.extractAuthorizationCode(URI("localhost://oauth?error=A%21&error_description=B%21&error_uri=http%3A%2F%2Fabc.de"))
+            extractAuthorizationCode("localhost://oauth?error=A%21&error_description=B%21&error_uri=http%3A%2F%2Fabc.de")
         } catch (e: OAuthException) {
             assertEquals("A!: B! (see http://abc.de)", e.message)
         }
@@ -110,15 +114,99 @@ class OAuthAuthorizationTest {
     @Test fun extractAuthorizationCode() {
         assertEquals(
             "my code",
-            createOAuth().extractAuthorizationCode(URI("localhost://oauth?code=my%20code"))
+            extractAuthorizationCode("localhost://oauth?code=my%20code")
+        )
+    }
+
+    @Test fun `retrieveAccessToken generates valid access token`() = runBlocking {
+        val service = OAuthService(HttpClient(MockEngine { _ -> respondOk("""{
+            "access_token": "TOKEN",
+            "token_type": "bearer",
+            "scope": "A B C"
+        }""")
+        }))
+
+        val tokenResponse = service.retrieveAccessToken(dummyOAuthAuthorization(), "")
+
+        assertEquals(AccessTokenResponse("TOKEN", listOf("A", "B", "C")), tokenResponse)
+    }
+
+    @Test fun `retrieveAccessToken throws OAuthConnectionException with invalid response token_type`(): Unit = runBlocking {
+        val service = OAuthService(HttpClient(MockEngine { _ -> respondOk("""{
+            "access_token": "TOKEN",
+            "token_type": "an_unusual_token_type",
+            "scope": "A B C"
+        }""")
+        }))
+
+        val exception = assertFailsWith<OAuthConnectionException> { service.retrieveAccessToken(dummyOAuthAuthorization(), "") }
+
+        assertEquals("OAuth 2 token endpoint returned an unknown token type (an_unusual_token_type)", exception.message)
+    }
+
+    @Test fun `retrieveAccessToken throws OAuthException when error response`(): Unit = runBlocking {
+        val service = OAuthService(HttpClient(MockEngine { _ ->
+            respondError(
+                HttpStatusCode.BadRequest, """{
+                    "error": "Missing auth code",
+                    "error_description": "Please specify a code",
+                    "error_uri": "code"
+                }"""
+            )
+        }))
+
+        val exception = assertFailsWith<OAuthException> {
+            service.retrieveAccessToken(dummyOAuthAuthorization(), "")
+        }
+
+        assertEquals("Missing auth code", exception.error)
+        assertEquals("Please specify a code", exception.description)
+        assertEquals("code", exception.uri)
+        assertEquals("Missing auth code: Please specify a code (see code)", exception.message)
+    }
+
+    @Test fun `retrieveAccessToken generates correct request URL`(): Unit = runBlocking {
+        val mockEngine = MockEngine { _ -> respondOk() }
+        val auth = OAuthAuthorizationParams(
+            "",
+            "https://www.openstreetmap.org",
+            "OAuthClientId",
+            listOf(),
+            "scheme://there"
         )
+
+        assertFails { OAuthService(HttpClient(mockEngine)).retrieveAccessToken(auth, "C0D3") }
+
+        val expectedParams = ParametersBuilder()
+        expectedParams.append("grant_type", "authorization_code")
+        expectedParams.append("client_id", "OAuthClientId")
+        expectedParams.append("code", "C0D3")
+        expectedParams.append("redirect_uri", "scheme://there")
+        expectedParams.append("code_verifier", auth.codeVerifier)
+
+        assertEquals(1, mockEngine.requestHistory.size)
+        assertEquals(expectedParams.build(), mockEngine.requestHistory[0].url.parameters)
+        assertEquals("www.openstreetmap.org", mockEngine.requestHistory[0].url.host)
     }
 
-    // it's not properly possible to test retrieveAccessToken in isolation because the http client
-    // is not injected (passed in the constructor)
+    @Test fun `retrieveAccessToken generates request headers`(): Unit = runBlocking {
+        val mockEngine = MockEngine { _ -> respondOk() }
+
+        assertFails { OAuthService(HttpClient(mockEngine)).retrieveAccessToken(dummyOAuthAuthorization(), "") }
+
+        val expectedHeaders = HeadersBuilder()
+        expectedHeaders.append("Content-Type", "application/x-www-form-urlencoded")
+        expectedHeaders.append("Accept-Charset", "UTF-8")
+        expectedHeaders.append("Accept", "*/*")
+
+        assertEquals(1, mockEngine.requestHistory.size)
+        assertEquals(expectedHeaders.build(), mockEngine.requestHistory[0].headers)
+    }
 }
 
-private fun createOAuth(state: String? = null) = OAuthAuthorization(
+private fun dummyOAuthAuthorization() = OAuthAuthorizationParams("", "", "", listOf(), "")
+
+private fun createOAuth(state: String? = null) = OAuthAuthorizationParams(
     "https://test.me/auth",
     "https://test.me/token",
     "ClientId %#+!",
@@ -126,11 +214,3 @@ private fun createOAuth(state: String? = null) = OAuthAuthorization(
     "localhost://oauth",
     state
 )
-
-private fun urlEncode(s: String) = URLEncoder.encode(s, "US-ASCII")
-
-private val URL.queryParameters get(): Map<String, String> =
-    query.split('&').associate {
-        val parts = it.split('=')
-        parts[0] to URLDecoder.decode(parts[1], "US-ASCII")
-    }
diff --git a/app/src/test/java/de/westnordost/streetcomplete/data/user/statistics/StatisticsDownloaderTest.kt b/app/src/test/java/de/westnordost/streetcomplete/data/user/statistics/StatisticsDownloaderTest.kt
new file mode 100644
index 00000000000..03ec69519c8
--- /dev/null
+++ b/app/src/test/java/de/westnordost/streetcomplete/data/user/statistics/StatisticsDownloaderTest.kt
@@ -0,0 +1,44 @@
+package de.westnordost.streetcomplete.data.user.statistics
+
+import de.westnordost.streetcomplete.testutils.mock
+import de.westnordost.streetcomplete.testutils.on
+import io.ktor.client.HttpClient
+import io.ktor.client.engine.mock.MockEngine
+import io.ktor.client.engine.mock.respondBadRequest
+import io.ktor.client.engine.mock.respondOk
+import kotlinx.coroutines.runBlocking
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFails
+
+class StatisticsDownloaderTest {
+    private val statisticsParser: StatisticsParser = mock()
+
+    private val validResponseMockEngine = MockEngine { _ -> respondOk("simple response") }
+
+    @Test fun `download parses all statistics`() = runBlocking {
+        val stats = Statistics(types = listOf(), countries = listOf(), rank = 2, daysActive = 100, currentWeekRank = 50, currentWeekTypes = listOf(), currentWeekCountries = listOf(), activeDates = listOf(), activeDatesRange = 100, isAnalyzing = false, lastUpdate = 10)
+        on(statisticsParser.parse("simple response")).thenReturn(stats)
+        assertEquals(stats, StatisticsDownloader(HttpClient(validResponseMockEngine), "", statisticsParser).download(100))
+    }
+
+    @Test fun `download throws Exception for a 400 response`() = runBlocking {
+        val mockEngine = MockEngine { _ -> respondBadRequest() }
+        val exception = assertFails { StatisticsDownloader(HttpClient(mockEngine), "", statisticsParser).download(100) }
+
+        assertEquals(
+            "Client request(GET http://localhost/?user_id=100) invalid: 400 Bad Request. Text: \"Bad Request\"",
+            exception.message
+        )
+    }
+
+    @Test fun `download constructs request URL`() = runBlocking {
+        StatisticsDownloader(
+            HttpClient(validResponseMockEngine),
+            "https://example.com/stats/",
+            statisticsParser
+        ).download(100)
+
+        assertEquals("https://example.com/stats/?user_id=100", validResponseMockEngine.requestHistory[0].url.toString())
+    }
+}
diff --git a/app/src/test/java/de/westnordost/streetcomplete/quests/accepts_cards/AddAcceptsCardsTest.kt b/app/src/test/java/de/westnordost/streetcomplete/quests/accepts_cards/AddAcceptsCardsTest.kt
index ef9d69bb35c..ee2f09f59c0 100644
--- a/app/src/test/java/de/westnordost/streetcomplete/quests/accepts_cards/AddAcceptsCardsTest.kt
+++ b/app/src/test/java/de/westnordost/streetcomplete/quests/accepts_cards/AddAcceptsCardsTest.kt
@@ -44,4 +44,22 @@ class AddAcceptsCardsTest {
         )
         assertEquals(1, questType.getApplicableElements(mapData).toList().size)
     }
+
+    @Test fun `applicable to weird shop values`() {
+        val mapData = TestMapDataWithGeometry(
+            listOf(
+                node(1, tags = mapOf("shop" to "dgfygyug", "name" to "Foobar")),
+            ),
+        )
+        assertEquals(1, questType.getApplicableElements(mapData).toList().size)
+    }
+
+    @Test fun `not applicable to vacant shop`() {
+        val mapData = TestMapDataWithGeometry(
+            listOf(
+                node(1, tags = mapOf("shop" to "vacant", "name" to "Foobar")),
+            ),
+        )
+        assertEquals(0, questType.getApplicableElements(mapData).toList().size)
+    }
 }
diff --git a/app/src/test/java/de/westnordost/streetcomplete/quests/oneway_suspects/TrafficFlowSegmentsApiTest.kt b/app/src/test/java/de/westnordost/streetcomplete/quests/oneway_suspects/TrafficFlowSegmentsApiTest.kt
index 10416556d6d..980d647bc93 100644
--- a/app/src/test/java/de/westnordost/streetcomplete/quests/oneway_suspects/TrafficFlowSegmentsApiTest.kt
+++ b/app/src/test/java/de/westnordost/streetcomplete/quests/oneway_suspects/TrafficFlowSegmentsApiTest.kt
@@ -5,51 +5,85 @@ import de.westnordost.streetcomplete.data.osm.mapdata.LatLon
 import de.westnordost.streetcomplete.quests.oneway_suspects.data.ONEWAY_API_URL
 import de.westnordost.streetcomplete.quests.oneway_suspects.data.TrafficFlowSegment
 import de.westnordost.streetcomplete.quests.oneway_suspects.data.TrafficFlowSegmentsApi
+import io.ktor.client.HttpClient
+import io.ktor.client.engine.mock.MockEngine
+import io.ktor.client.engine.mock.respondBadRequest
+import io.ktor.client.engine.mock.respondError
+import io.ktor.client.engine.mock.respondOk
+import io.ktor.client.plugins.ClientRequestException
+import io.ktor.client.plugins.ServerResponseException
+import io.ktor.http.HttpStatusCode
+import kotlinx.coroutines.runBlocking
 import kotlin.test.Test
 import kotlin.test.assertEquals
-import kotlin.test.assertTrue
+import kotlin.test.assertFailsWith
 
 class TrafficFlowSegmentsApiTest {
+    private val boundingBox = BoundingBox(
+        -34.0,
+        18.0,
+        -33.0,
+        19.0
+    )
 
-    @Test fun parseEmptyDoesNotResultInError() {
-        val result = TrafficFlowSegmentsApi.parse("{\"segments\":[]}")
-        assertTrue(result.isEmpty())
+    @Test fun `get with empty response does not result in error`(): Unit = runBlocking {
+        val mockEngine = MockEngine { request -> respondOk("""{"segments": []}""") }
+
+        assertEquals(mapOf(), TrafficFlowSegmentsApi(HttpClient(mockEngine), ONEWAY_API_URL).get(boundingBox))
     }
 
-    @Test fun parseTwoOfDifferentWay() {
+    @Test fun `get with two different ways`() = runBlocking {
+        val mockEngine = MockEngine { request -> respondOk("""
+            {"segments":[
+                {"wayId":1,"fromPosition":{"lon":1, "lat":2},"toPosition":{"lon":5, "lat":6}},
+                {"wayId":2,"fromPosition":{"lon":3, "lat":4},"toPosition":{"lon":7, "lat":8}}
+            ]}
+        """) }
+
         assertEquals(
             mapOf(
                 1L to listOf(TrafficFlowSegment(1L, LatLon(2.0, 1.0), LatLon(6.0, 5.0))),
                 2L to listOf(TrafficFlowSegment(2L, LatLon(4.0, 3.0), LatLon(8.0, 7.0)))
             ),
-            TrafficFlowSegmentsApi.parse("""
-                {"segments":[
-                    {"wayId":1,"fromPosition":{"lon":1, "lat":2},"toPosition":{"lon":5, "lat":6}},
-                    {"wayId":2,"fromPosition":{"lon":3, "lat":4},"toPosition":{"lon":7, "lat":8}}
-                ]}
-                """.trimIndent()
-            )
+            TrafficFlowSegmentsApi(HttpClient(mockEngine), ONEWAY_API_URL).get(boundingBox)
         )
     }
 
-    @Test fun parseTwoOfSameWay() {
+    @Test fun `get with two of same way`() = runBlocking {
+        val mockEngine = MockEngine { request -> respondOk("""
+            {"segments":[
+                {"wayId":1,"fromPosition":{"lon":1, "lat":2},"toPosition":{"lon":5, "lat":6}},
+                {"wayId":1,"fromPosition":{"lon":3, "lat":4},"toPosition":{"lon":7, "lat":8}}
+            ]}
+        """) }
+
         assertEquals(
             mapOf(1L to listOf(
                 TrafficFlowSegment(1L, LatLon(2.0, 1.0), LatLon(6.0, 5.0)),
                 TrafficFlowSegment(1L, LatLon(4.0, 3.0), LatLon(8.0, 7.0))
             )),
-            TrafficFlowSegmentsApi.parse("""
-                {"segments":[
-                    {"wayId":1,"fromPosition":{"lon":1, "lat":2},"toPosition":{"lon":5, "lat":6}},
-                    {"wayId":1,"fromPosition":{"lon":3, "lat":4},"toPosition":{"lon":7, "lat":8}}
-                ]}
-                """.trimIndent()
-            )
+            TrafficFlowSegmentsApi(HttpClient(mockEngine), ONEWAY_API_URL).get(boundingBox)
         )
     }
 
-    @Test fun withSomeRealData() {
-        // should just not crash...
-        TrafficFlowSegmentsApi(ONEWAY_API_URL).get(BoundingBox(-34.0, 18.0, -33.0, 19.0))
+    @Test fun `get throws an ClientRequestException on a 400 response`(): Unit = runBlocking {
+        val mockEngine = MockEngine { request -> respondBadRequest() }
+        assertFailsWith<ClientRequestException> { TrafficFlowSegmentsApi(HttpClient(mockEngine), ONEWAY_API_URL).get(boundingBox) }
+    }
+
+    @Test fun `get throws an ServerResponseException on a 500 response`(): Unit = runBlocking {
+        val mockEngine = MockEngine { request -> respondError(HttpStatusCode.InternalServerError) }
+        assertFailsWith<ServerResponseException> { TrafficFlowSegmentsApi(HttpClient(mockEngine), ONEWAY_API_URL).get(boundingBox) }
+    }
+
+    @Test fun `get makes request to correct URL`(): Unit = runBlocking {
+        val mockEngine = MockEngine { request -> respondOk("""{"segments": []}""") }
+
+        TrafficFlowSegmentsApi(HttpClient(mockEngine), ONEWAY_API_URL).get(boundingBox)
+
+        assertEquals(
+            ONEWAY_API_URL + "?bbox=18.0000000,-34.0000000,19.0000000,-33.0000000",
+            mockEngine.requestHistory[0].url.toString()
+        )
     }
 }
diff --git a/app/src/test/java/de/westnordost/streetcomplete/quests/smoking/AddSmokingTest.kt b/app/src/test/java/de/westnordost/streetcomplete/quests/smoking/AddSmokingTest.kt
index aaf7ae06b7a..aa211aaf609 100644
--- a/app/src/test/java/de/westnordost/streetcomplete/quests/smoking/AddSmokingTest.kt
+++ b/app/src/test/java/de/westnordost/streetcomplete/quests/smoking/AddSmokingTest.kt
@@ -50,7 +50,7 @@ class AddSmokingTest {
         ))))
     }
 
-    /* we assume that seating is not present if not indicated for bakery and similar */
+    // we assume that seating is not present if not indicated for bakery and similar
     @Test fun `not applicable to bakery without indicated seating`() {
         assertFalse(questType.isApplicableTo(node(tags = mapOf(
             "shop" to "bakery",
@@ -105,7 +105,7 @@ class AddSmokingTest {
         ))))
     }
 
-    /* nighclubs etc. may have outdoor smoking areas even if no seating is present */
+    // nighclubs etc. may have outdoor smoking areas even if no seating is present
     @Test fun `applicable to nightclub without any seating`() {
         assertTrue(questType.isApplicableTo(node(tags = mapOf(
             "amenity" to "nightclub",
@@ -120,7 +120,7 @@ class AddSmokingTest {
         ))))
     }
 
-    /* we assume that seating is present if not indicated for cafe and similar */
+    // we assume that seating is present if not indicated for cafe and similar
     @Test fun `applicable to cafe without indicated seating`() {
         assertTrue(questType.isApplicableTo(node(tags = mapOf(
             "amenity" to "cafe",
diff --git a/app/src/test/resources/image_uploader/empty.jpg b/app/src/test/resources/image_uploader/empty.jpg
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/app/src/test/resources/image_uploader/invalid.jpg b/app/src/test/resources/image_uploader/invalid.jpg
new file mode 100644
index 00000000000..9977a2836c1
--- /dev/null
+++ b/app/src/test/resources/image_uploader/invalid.jpg
@@ -0,0 +1 @@
+invalid
diff --git a/app/src/test/resources/image_uploader/ioexception.jpg b/app/src/test/resources/image_uploader/ioexception.jpg
new file mode 100644
index 00000000000..abfff0458b5
--- /dev/null
+++ b/app/src/test/resources/image_uploader/ioexception.jpg
@@ -0,0 +1 @@
+ioexception
diff --git a/app/src/test/resources/image_uploader/valid.jpg b/app/src/test/resources/image_uploader/valid.jpg
new file mode 100644
index 00000000000..1e2466dfadd
--- /dev/null
+++ b/app/src/test/resources/image_uploader/valid.jpg
@@ -0,0 +1 @@
+valid
diff --git a/buildSrc/src/main/java/DownloadAndConvertPresetIconsTask.kt b/buildSrc/src/main/java/DownloadAndConvertPresetIconsTask.kt
index 170e2688d83..3f81275073b 100644
--- a/buildSrc/src/main/java/DownloadAndConvertPresetIconsTask.kt
+++ b/buildSrc/src/main/java/DownloadAndConvertPresetIconsTask.kt
@@ -109,7 +109,7 @@ open class DownloadAndConvertPresetIconsTask : DefaultTask() {
         }
 
         require(root != null) { "No root node found" }
-        require(root.tagName  == "svg") { "Root must be <svg>" }
+        require(root.tagName == "svg") { "Root must be <svg>" }
 
         var width = root.getAttribute("width")
         var height = root.getAttribute("height")