Implement OpenStreetMap data source

app/src/main/java/net/vonforst/evmap/adapter/DetailsAdapter.kt

@@ -14,6 +14,7 @@ import net.vonforst.evmap.joinToSpannedString
 import net.vonforst.evmap.model.ChargeCard
 import net.vonforst.evmap.model.ChargeCardId
 import net.vonforst.evmap.model.ChargeLocation
+import net.vonforst.evmap.model.Coordinate
 import net.vonforst.evmap.model.OpeningHoursDays
 import net.vonforst.evmap.plus
 import net.vonforst.evmap.ui.currency

app/src/main/java/net/vonforst/evmap/api/ChargepointApi.kt

@@ -6,6 +6,7 @@ import com.car2go.maps.model.LatLngBounds
 import net.vonforst.evmap.R
 import net.vonforst.evmap.api.goingelectric.GoingElectricApiWrapper
 import net.vonforst.evmap.api.openchargemap.OpenChargeMapApiWrapper
+import net.vonforst.evmap.api.openstreetmap.OpenStreetMapApiWrapper
 import net.vonforst.evmap.model.*
 import net.vonforst.evmap.viewmodel.Resource
 import java.time.Duration
@@ -58,6 +59,27 @@ interface ChargepointApi<out T : ReferenceData> {
      * Duration we are limited to if there is a required API local cache time limit.
      */
     val cacheLimit: Duration
+
+    /**
+     * Whether this API supports querying for chargers at the backend
+     *
+     * This determines whether the getChargepoints, getChargepointsRadius and getChargepointDetail functions are supported.
+     */
+    val supportsOnlineQueries: Boolean
+
+    /**
+     * Whether this API supports downloading the whole dataset into local storage
+     *
+     * This determines whether the getAllChargepoints function is supported.
+     */
+    val supportsFullDownload: Boolean
+
+    /**
+     * Fetches all available chargers from this API.
+     *
+     * This may take a long time and should only be used when the user explicitly wants to download all chargers.
+     */
+    suspend fun fullDownload(): FullDownloadResult<T>
 }
 
 interface StringProvider {
@@ -79,13 +101,19 @@ fun createApi(type: String, ctx: Context): ChargepointApi<ReferenceData> {
                 )
             )
         }
+
         "goingelectric" -> {
             GoingElectricApiWrapper(
                 ctx.getString(
                     R.string.goingelectric_key
                 )
             )
         }
+
+        "openstreetmap" -> {
+            OpenStreetMapApiWrapper()
+        }
+
         else -> throw IllegalArgumentException()
     }
 }
@@ -100,4 +128,20 @@ data class ChargepointList(val items: List<ChargepointListItem>, val isComplete:
     companion object {
         fun empty() = ChargepointList(emptyList(), true)
     }
+}
+
+/**
+ * Result returned from fullDownload() function.
+ *
+ * Note that [chargers] is implemented as a [Sequence] so that downloaded chargers can be saved
+ * while they are being parsed instead of having to keep all of them in RAM at once.
+ *
+ * [progress] is updated regularly to indicate the current download progress.
+ * [referenceData] will typically only be available once the download is completed, i.e. you have
+ * iterated over the whole sequence of [chargers].
+ */
+interface FullDownloadResult<out T : ReferenceData> {
+    val chargers: Sequence<ChargeLocation>
+    val progress: Float
+    val referenceData: T
 }

app/src/main/java/net/vonforst/evmap/api/Utils.kt

@@ -11,6 +11,7 @@ import okhttp3.Response
 import org.json.JSONArray
 import java.io.IOException
 import kotlin.coroutines.resumeWithException
+import kotlin.experimental.ExperimentalTypeInference
 import kotlin.math.abs
 
 operator fun <T> JSONArray.iterator(): Iterator<T> =

app/src/main/java/net/vonforst/evmap/api/availability/EnBwAvailabilityDetector.kt

@@ -242,8 +242,8 @@ class EnBwAvailabilityDetector(client: OkHttpClient, baseUrl: String? = null) :
     }
 
     override fun isChargerSupported(charger: ChargeLocation): Boolean {
-        val country = charger.chargepriceData?.country
-            ?: charger.address?.country ?: return false
+        val country = charger.chargepriceData?.country ?: charger.address?.country
+
         return when (charger.dataSource) {
             // list of countries as of 2023/04/14, according to
             // https://www.enbw.com/elektromobilitaet/produkte/ladetarife
@@ -285,6 +285,12 @@ class EnBwAvailabilityDetector(client: OkHttpClient, baseUrl: String? = null) :
                 "ES",
                 "CZ"
             ) && charger.chargepriceData?.network !in listOf("23", "3534")
+            /* TODO: OSM usually does not have the country tagged. Therefore we currently just use
+               a bounding box to determine whether the charger is roughly in Europe */
+            "openstreetmap" -> charger.coordinates.lat in 35.0..72.0
+                    && charger.coordinates.lng in 25.0..65.0
+                    && charger.operator !in listOf("Tesla, Inc.", "Tesla")
+
             else -> false
         }
     }

app/src/main/java/net/vonforst/evmap/api/availability/NewMotionAvailabilityDetector.kt

@@ -221,6 +221,7 @@ class NewMotionAvailabilityDetector(client: OkHttpClient, baseUrl: String? = nul
         return when (charger.dataSource) {
             "goingelectric" -> charger.network != "Tesla Supercharger"
             "openchargemap" -> charger.chargepriceData?.network !in listOf("23", "3534")
+            "openstreetmap" -> charger.operator !in listOf("Tesla, Inc.", "Tesla")
             else -> false
         }
     }

app/src/main/java/net/vonforst/evmap/api/availability/TeslaGuestAvailabilityDetector.kt

@@ -23,6 +23,10 @@ class TeslaGuestAvailabilityDetector(
     private var api = TeslaChargingGuestGraphQlApi.create(client, baseUrl)
 
     override suspend fun getAvailability(location: ChargeLocation): ChargeLocationStatus {
+        if (location.chargepoints.isEmpty() || location.chargepoints.any { !it.hasKnownPower() }) {
+            throw AvailabilityDetectorException("no candidates found.")
+        }
+
         val results = cuaApi.getTeslaLocations()
 
         val result =
@@ -163,6 +167,7 @@ class TeslaGuestAvailabilityDetector(
         return when (charger.dataSource) {
             "goingelectric" -> charger.network == "Tesla Supercharger"
             "openchargemap" -> charger.chargepriceData?.network in listOf("23", "3534")
+            "openstreetmap" -> charger.operator in listOf("Tesla, Inc.", "Tesla")
             else -> false
         }
     }

app/src/main/java/net/vonforst/evmap/api/availability/TeslaOwnerAvailabilityDetector.kt

@@ -29,6 +29,10 @@ class TeslaOwnerAvailabilityDetector(
     }
 
     override suspend fun getAvailability(location: ChargeLocation): ChargeLocationStatus {
+        if (location.chargepoints.isEmpty() || location.chargepoints.any { !it.hasKnownPower() }) {
+            throw AvailabilityDetectorException("no candidates found.")
+        }
+
         val api = initApi()
         val req = TeslaChargingOwnershipGraphQlApi.GetNearbyChargingSitesRequest(
             TeslaChargingOwnershipGraphQlApi.GetNearbyChargingSitesVariables(
@@ -162,6 +166,7 @@ class TeslaOwnerAvailabilityDetector(
         return when (charger.dataSource) {
             "goingelectric" -> charger.network == "Tesla Supercharger"
             "openchargemap" -> charger.chargepriceData?.network in listOf("23", "3534")
+            "openstreetmap" -> charger.operator in listOf("Tesla, Inc.", "Tesla")
             else -> false
         }
     }

app/src/main/java/net/vonforst/evmap/api/goingelectric/GoingElectricApi.kt

@@ -15,6 +15,7 @@ import net.vonforst.evmap.addDebugInterceptors
 import net.vonforst.evmap.api.ChargepointApi
 import net.vonforst.evmap.api.ChargepointList
 import net.vonforst.evmap.api.FiltersSQLQuery
+import net.vonforst.evmap.api.FullDownloadResult
 import net.vonforst.evmap.api.StringProvider
 import net.vonforst.evmap.api.mapPower
 import net.vonforst.evmap.api.mapPowerInverse
@@ -159,6 +160,12 @@ class GoingElectricApiWrapper(
     override val name = "GoingElectric.de"
     override val id = "goingelectric"
     override val cacheLimit = Duration.ofDays(1)
+    override val supportsOnlineQueries = true
+    override val supportsFullDownload = false
+
+    override suspend fun fullDownload(): FullDownloadResult<GEReferenceData> {
+        throw NotImplementedError()
+    }
 
     override suspend fun getChargepoints(
         referenceData: ReferenceData,

app/src/main/java/net/vonforst/evmap/api/openchargemap/OpenChargeMapApi.kt

@@ -11,6 +11,7 @@ import net.vonforst.evmap.addDebugInterceptors
 import net.vonforst.evmap.api.ChargepointApi
 import net.vonforst.evmap.api.ChargepointList
 import net.vonforst.evmap.api.FiltersSQLQuery
+import net.vonforst.evmap.api.FullDownloadResult
 import net.vonforst.evmap.api.StringProvider
 import net.vonforst.evmap.api.mapPower
 import net.vonforst.evmap.api.mapPowerInverse
@@ -130,6 +131,12 @@ class OpenChargeMapApiWrapper(
 
     override val name = "OpenChargeMap.org"
     override val id = "openchargemap"
+    override val supportsOnlineQueries = true
+    override val supportsFullDownload = false
+
+    override suspend fun fullDownload(): FullDownloadResult<OCMReferenceData> {
+        throw NotImplementedError()
+    }
 
     private fun formatMultipleChoice(value: MultipleChoiceFilterValue?) =
         if (value == null || value.all) null else value.values.joinToString(",")

app/src/main/java/net/vonforst/evmap/api/openstreetmap/OpenStreetMapAdapters.kt

@@ -0,0 +1,67 @@
+package net.vonforst.evmap.api.openstreetmap
+
+import com.squareup.moshi.FromJson
+import com.squareup.moshi.JsonReader
+import com.squareup.moshi.Moshi
+import com.squareup.moshi.ToJson
+import com.squareup.moshi.rawType
+import okhttp3.ResponseBody
+import retrofit2.Converter
+import retrofit2.Retrofit
+import java.lang.reflect.Type
+import java.time.Instant
+import kotlin.math.floor
+
+internal class InstantAdapter {
+    @FromJson
+    fun fromJson(value: Double?): Instant? = value?.let {
+        val seconds = floor(it).toLong()
+        val nanos = ((value - seconds) * 1e9).toLong()
+        Instant.ofEpochSecond(seconds, nanos)
+    }
+
+    @ToJson
+    fun toJson(value: Instant?): Double? = value?.let {
+        it.epochSecond.toDouble() + it.nano / 1e9
+    }
+}
+
+internal class OSMConverterFactory(val moshi: Moshi) : Converter.Factory() {
+    override fun responseBodyConverter(
+        type: Type,
+        annotations: Array<out Annotation>,
+        retrofit: Retrofit
+    ): Converter<ResponseBody, *>? {
+        if (type.rawType != OSMDocument::class.java) return null
+
+        val instantAdapter = moshi.adapter(Instant::class.java)
+        val osmChargingStationAdapter = moshi.adapter(OSMChargingStation::class.java)
+        val longAdapter = moshi.adapter(Long::class.java)
+        return Converter<ResponseBody, OSMDocument> { body ->
+            val reader = JsonReader.of(body.source())
+            reader.beginObject()
+
+            var timestamp: Instant? = null
+            var doc: Sequence<OSMChargingStation>? = null
+            var count: Long? = null
+            while (reader.hasNext()) {
+                when (reader.nextName()) {
+                    "timestamp" -> timestamp = instantAdapter.fromJson(reader)!!
+                    "count" -> count = longAdapter.fromJson(reader)!!
+                    "elements" -> {
+                        doc = sequence {
+                            reader.beginArray()
+                            while (reader.hasNext()) {
+                                yield(osmChargingStationAdapter.fromJson(reader)!!)
+                            }
+                            reader.endArray()
+                            reader.close()
+                        }
+                        break
+                    }
+                }
+            }
+            OSMDocument(timestamp!!, count!!, doc!!)
+        }
+    }
+}