Use CustomTabs instead of WebView for login

app/build.gradle.kts

@@ -118,6 +118,7 @@ android {
 
 dependencies {
     implementation(project(":common"))
+    implementation(libs.androidx.browser)
 
     coreLibraryDesugaring(libs.tools.desugar.jdk)
 

app/src/main/AndroidManifest.xml

@@ -306,7 +306,19 @@
         <activity
             android:name=".onboarding.OnboardingActivity"
             android:configChanges="orientation|screenSize|keyboard|keyboardHidden|navigation"
-            android:theme="@style/Theme.HomeAssistant.Config" />
+            android:theme="@style/Theme.HomeAssistant.Config"
+            android:exported="true">
+
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+
+                <data
+                    android:scheme="homeassistant"
+                    android:host="auth-callback" />
+            </intent-filter>
+        </activity>
 
         <activity
             android:name=".settings.wear.SettingsWearActivity"

app/src/main/java/io/homeassistant/companion/android/onboarding/OnboardingActivity.kt

@@ -1,26 +1,62 @@
 package io.homeassistant.companion.android.onboarding
 
+import android.content.Context
+import android.content.Intent
+import android.net.Uri
 import android.os.Build
 import android.os.Bundle
+import android.util.Log
 import android.view.KeyEvent
+import android.widget.Toast
 import androidx.activity.OnBackPressedCallback
 import androidx.activity.viewModels
+import androidx.browser.customtabs.CustomTabsIntent
 import androidx.core.app.NotificationManagerCompat
 import androidx.fragment.app.commit
 import dagger.hilt.android.AndroidEntryPoint
 import io.homeassistant.companion.android.BaseActivity
 import io.homeassistant.companion.android.BuildConfig
 import io.homeassistant.companion.android.R
-import io.homeassistant.companion.android.onboarding.authentication.AuthenticationFragment
+import io.homeassistant.companion.android.common.data.authentication.impl.AuthenticationService
 import io.homeassistant.companion.android.onboarding.discovery.DiscoveryFragment
+import io.homeassistant.companion.android.onboarding.integration.MobileAppIntegrationFragment
 import io.homeassistant.companion.android.onboarding.manual.ManualSetupFragment
 import io.homeassistant.companion.android.onboarding.welcome.WelcomeFragment
+import okhttp3.HttpUrl
+import okhttp3.HttpUrl.Companion.toHttpUrl
 
 @AndroidEntryPoint
 class OnboardingActivity : BaseActivity() {
 
     companion object {
         private const val AUTHENTICATION_FRAGMENT = "authentication_fragment"
+        const val AUTH_CALLBACK = "homeassistant://auth-callback"
+        private const val TAG = "OnboardingActivity"
+
+        fun buildAuthUrl(context: Context, base: String): String {
+            return try {
+                val url = base.toHttpUrl()
+                val builder = if (url.host.endsWith("ui.nabu.casa", true)) {
+                    HttpUrl.Builder()
+                        .scheme(url.scheme)
+                        .host(url.host)
+                        .port(url.port)
+                } else {
+                    url.newBuilder()
+                }
+                builder
+                    .addPathSegments("auth/authorize")
+                    .addEncodedQueryParameter("response_type", "code")
+                    .addEncodedQueryParameter("client_id", AuthenticationService.CLIENT_ID)
+                    .addEncodedQueryParameter("redirect_uri", AUTH_CALLBACK)
+                    .build()
+                    .toString()
+            } catch (e: Exception) {
+                Log.e(TAG, "Unable to build authentication URL", e)
+                Toast.makeText(context, io.homeassistant.companion.android.common.R.string.error_connection_failed, Toast.LENGTH_LONG).show()
+                ""
+            }
+        }
     }
 
     private val viewModel by viewModels<OnboardingViewModel>()
@@ -66,15 +102,22 @@ class OnboardingActivity : BaseActivity() {
                         }
                     }
                     if (viewModel.manualContinueEnabled) {
-                        supportFragmentManager.commit {
-                            replace(R.id.content, AuthenticationFragment::class.java, null)
-                            addToBackStack(null)
-                        }
+                        val uri = buildAuthUrl(baseContext, input.url)
+                        val builder = CustomTabsIntent.Builder()
+                        val customTabsIntent = builder.build()
+                        customTabsIntent.launchUrl(baseContext, Uri.parse(uri))
                     }
                 }
             }
         }
 
+        if (intent?.action == Intent.ACTION_VIEW && intent.data != null) {
+            val uri = intent.data
+            if (uri != null && uri.scheme == "homeassistant") {
+                handleAuthCallback(uri.toString())
+            }
+        }
+
         val onBackPressed = object : OnBackPressedCallback(supportFragmentManager.backStackEntryCount > 0) {
             override fun handleOnBackPressed() {
                 supportFragmentManager.popBackStack()
@@ -86,6 +129,18 @@ class OnboardingActivity : BaseActivity() {
         }
     }
 
+    private fun handleAuthCallback(url: String) {
+        val code = Uri.parse(url).getQueryParameter("code")
+        if (url.startsWith(AUTH_CALLBACK) && !code.isNullOrBlank()) {
+            viewModel.registerAuthCode(code)
+            supportFragmentManager
+                .beginTransaction()
+                .replace(R.id.content, MobileAppIntegrationFragment::class.java, null)
+                .addToBackStack(null)
+                .commit()
+        }
+    }
+
     override fun dispatchKeyEvent(event: KeyEvent): Boolean {
         // Workaround to sideload on Android TV and use a remote for basic navigation in WebView
         val fragmentManager = supportFragmentManager.findFragmentByTag(AUTHENTICATION_FRAGMENT)