composeApp/src/androidMain/kotlin/su/reya/coop/AndroidExternalSigner.kt

@@ -12,7 +12,6 @@ class AndroidExternalSigner(
     private val launcher: ExternalSignerLauncher,
 ) : ExternalSignerHandler {
     private var cachedPackageName: String? = null
-    private var cachedPublicKey: PublicKey? = null
 
     private data class ContentResolverResult(
         val result: String,
@@ -26,9 +25,15 @@ class AndroidExternalSigner(
         currentUser: PublicKey? = null,
     ): ContentResolverResult? {
         val uri = "content://$cachedPackageName.${type.uppercase()}".toUri()
+        val projection = mutableListOf<String?>().apply {
+            add(payload)
+            add(pubkey?.toHex() ?: "")
+            add(currentUser?.toHex() ?: "")
+        }
+
         val cursor = context.contentResolver.query(
             uri,
-            listOf(payload, pubkey, currentUser) as Array<out String?>?,
+            projection.toTypedArray(),
             null, null, null,
         ) ?: return null
 
@@ -79,6 +84,10 @@ class AndroidExternalSigner(
         return context.packageManager.queryIntentActivities(intent, 0).isNotEmpty()
     }
 
+    override fun setPackageName(packageName: String) {
+        cachedPackageName = packageName
+    }
+
     override suspend fun getPublicKey(permissions: String?): ExternalSignerResult? {
         val intent = Intent(Intent.ACTION_VIEW, "nostrsigner:".toUri()).apply {
             putExtra("type", "get_public_key")
@@ -93,8 +102,9 @@ class AndroidExternalSigner(
 
         val pubkey = data.getStringExtra("result") ?: return null
         val packageName = data.getStringExtra("package") ?: return null
+        cachedPackageName = packageName
 
-        return ExternalSignerResult(pubkey, packageName)
+        return ExternalSignerResult(PublicKey.parse(pubkey), packageName)
     }
 
     override suspend fun signEvent(event: UnsignedEvent, currentUser: PublicKey): String? {

composeApp/src/androidMain/kotlin/su/reya/coop/ExternalSigner.kt

@@ -1,166 +0,0 @@
-package su.reya.coop
-
-import android.app.Activity
-import android.content.Context
-import android.content.Intent
-import androidx.core.net.toUri
-import rust.nostr.sdk.AsyncNostrSigner
-import rust.nostr.sdk.Event
-import rust.nostr.sdk.PublicKey
-import rust.nostr.sdk.UnsignedEvent
-
-data class SignerResult(
-    val result: String,
-    val event: Event? = null,
-)
-
-class ExternalSigner(
-    private val context: Context,
-    private val packageName: String,
-    private val currentUser: PublicKey,
-    private val launcher: ExternalSignerLauncher,
-) : AsyncNostrSigner {
-    private fun queryContentResolver(
-        type: String,
-        payload: String,
-        pubkey: PublicKey? = null
-    ): SignerResult? {
-        val uri = "content://$packageName.${type.uppercase()}".toUri()
-        val projection = mutableListOf<String>()
-        projection.add(payload)
-        if (pubkey != null) projection.add(pubkey.toHex())
-        projection.add(currentUser.toHex())
-
-        val cursor = context.contentResolver.query(
-            uri,
-            projection.toList() as Array<out String?>?,
-            null, null, null,
-        ) ?: return null
-
-        return cursor.use {
-            if (it.getColumnIndex("rejected") > -1) return null
-
-            if (it.moveToFirst()) {
-                val resultIndex = it.getColumnIndex(payload)
-                val result = if (resultIndex > -1) it.getString(resultIndex) else null
-
-                val eventIndex = it.getColumnIndex("event")
-                val event = if (eventIndex > -1) it.getString(eventIndex) else null
-
-                SignerResult(result = result!!, event = Event.fromJson(event!!))
-            } else {
-                null
-            }
-        }
-    }
-
-    private suspend fun requestViaIntent(
-        type: String,
-        payload: String,
-        extras: Map<String, String> = emptyMap()
-    ): String {
-        val intent = Intent(Intent.ACTION_VIEW, "nostrsigner:$payload".toUri()).apply {
-            `package` = packageName
-            putExtra("type", type)
-            putExtra("current_user", currentUser.toHex())
-            extras.forEach { (k, v) -> putExtra(k, v) }
-        }
-
-        val result = launcher.launch(intent)
-
-        if (result.resultCode != Activity.RESULT_OK) {
-            throw Exception("Signer returned error (resultCode=${result.resultCode})")
-        }
-
-        val data = result.data ?: throw Exception("Signer returned no data")
-
-        if (data.getBooleanExtra("rejected", false)) {
-            throw Exception("User rejected the request")
-        }
-
-        return data.getStringExtra("result") ?: throw Exception("Signer returned no result")
-    }
-
-    private suspend fun request(
-        type: String,
-        payload: String,
-        pubkey: PublicKey? = null,
-        currentUser: PublicKey? = null,
-        extras: Map<String, String> = emptyMap()
-    ): String {
-        // Try silent Content Resolver first
-        queryContentResolver(type, payload, pubkey)?.let { return it.result }
-
-        // Fall back to Intent
-        val allExtras = extras.toMutableMap().apply {
-            if (pubkey != null) put("pubkey", pubkey.toHex())
-            if (currentUser != null) put("current_user", currentUser.toHex())
-        }
-
-        return requestViaIntent(type, payload, allExtras)
-    }
-
-    override suspend fun getPublicKeyAsync(): PublicKey {
-        return currentUser
-    }
-
-    override suspend fun signEventAsync(unsignedEvent: UnsignedEvent): Event? {
-        val eventJson = unsignedEvent.asJson()
-
-        // Try Content Resolver first
-        val contentResult = queryContentResolver("sign_event", eventJson)
-        contentResult?.event?.let { return it }
-
-        // Fall back to Intent
-        val intent = Intent(Intent.ACTION_VIEW, "nostrsigner:$eventJson".toUri()).apply {
-            `package` = packageName
-            putExtra("type", "sign_event")
-            putExtra("current_user", currentUser.toHex())
-            putExtra("id", unsignedEvent.id()?.toHex() ?: "")
-        }
-
-        val result = launcher.launch(intent)
-        if (result.resultCode != Activity.RESULT_OK) return null
-
-        val data = result.data ?: return null
-        if (data.getBooleanExtra("rejected", false)) return null
-
-        val signedEventJson = data.getStringExtra("event")
-
-        return signedEventJson?.let { Event.fromJson(it) }
-    }
-
-    override suspend fun nip04EncryptAsync(publicKey: PublicKey, content: String): String {
-        return request(
-            "nip04_encrypt",
-            payload = content,
-            pubkey = publicKey
-        )
-    }
-
-    override suspend fun nip04DecryptAsync(publicKey: PublicKey, encryptedContent: String): String {
-        return request(
-            "nip04_decrypt",
-            payload = encryptedContent,
-            pubkey = publicKey
-        )
-    }
-
-    override suspend fun nip44EncryptAsync(publicKey: PublicKey, content: String): String {
-        return request(
-            "nip44_encrypt",
-            payload = content,
-            pubkey = publicKey,
-            currentUser = currentUser
-        )
-    }
-
-    override suspend fun nip44DecryptAsync(publicKey: PublicKey, payload: String): String {
-        return request(
-            "nip44_decrypt",
-            payload = payload,
-            pubkey = publicKey,
-            currentUser = currentUser
-        )
-    }
-}

composeApp/src/androidMain/kotlin/su/reya/coop/MainActivity.kt

@@ -81,4 +81,9 @@ class MainActivity : ComponentActivity() {
         super.onNewIntent(intent)
         setIntent(intent)
     }
+
+    override fun onDestroy() {
+        externalSignerLauncher.unregister()
+        super.onDestroy()
+    }
 }

composeApp/src/androidMain/kotlin/su/reya/coop/screens/OnboardingScreen.kt

@@ -1,5 +1,6 @@
 package su.reya.coop.screens
 
+import android.content.Intent
 import androidx.compose.foundation.Canvas
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
@@ -13,13 +14,17 @@ import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.Button
 import androidx.compose.material3.ButtonDefaults
 import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
+import androidx.compose.material3.FilledTonalButton
 import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.OutlinedButton
 import androidx.compose.material3.Scaffold
+import androidx.compose.material3.SnackbarDuration
 import androidx.compose.material3.SnackbarHost
+import androidx.compose.material3.SnackbarResult
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.geometry.Size
@@ -27,6 +32,7 @@ import androidx.compose.ui.graphics.ColorFilter
 import androidx.compose.ui.graphics.drawscope.rotate
 import androidx.compose.ui.graphics.drawscope.translate
 import androidx.compose.ui.graphics.painter.Painter
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.text.LinkAnnotation
 import androidx.compose.ui.text.SpanStyle
 import androidx.compose.ui.text.TextLinkStyles
@@ -34,10 +40,13 @@ import androidx.compose.ui.text.buildAnnotatedString
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
+import androidx.core.net.toUri
 import coop.composeapp.generated.resources.Res
 import coop.composeapp.generated.resources.coop
+import kotlinx.coroutines.launch
 import org.jetbrains.compose.resources.painterResource
 import su.reya.coop.LocalNavigator
+import su.reya.coop.LocalNostrViewModel
 import su.reya.coop.LocalSnackbarHostState
 import su.reya.coop.Screen
 import su.reya.coop.shared.getExpressiveFontFamily
@@ -45,8 +54,11 @@ import su.reya.coop.shared.getExpressiveFontFamily
 @OptIn(ExperimentalMaterial3ExpressiveApi::class)
 @Composable
 fun OnboardingScreen() {
+    val context = LocalContext.current
     val snackbarHostState = LocalSnackbarHostState.current
     val navigator = LocalNavigator.current
+    val viewModel = LocalNostrViewModel.current
+    val scope = rememberCoroutineScope()
 
     val logoPainter = painterResource(Res.drawable.coop)
     val expressiveFont = getExpressiveFontFamily()
@@ -142,7 +154,44 @@ fun OnboardingScreen() {
                                 )
                             }
                             Spacer(modifier = Modifier.size(8.dp))
-                            OutlinedButton(
+                            FilledTonalButton(
+                                onClick = {
+                                    scope.launch {
+                                        if (viewModel.isExternalSignerAvailable()) {
+                                            try {
+                                                viewModel.connectExternalSigner()
+                                                navigator.navigate(Screen.Home)
+                                            } catch (e: Exception) {
+                                                e.message?.let { snackbarHostState.showSnackbar(it) }
+                                            }
+                                        } else {
+                                            val result = snackbarHostState.showSnackbar(
+                                                message = "External signer not installed. Please install Amber or alternatives.",
+                                                actionLabel = "Install",
+                                                withDismissAction = true,
+                                                duration = SnackbarDuration.Long
+                                            )
+                                            if (result == SnackbarResult.ActionPerformed) {
+                                                val intent = Intent(
+                                                    Intent.ACTION_VIEW,
+                                                    "https://zapstore.dev/apps/com.greenart7c3.nostrsigner".toUri()
+                                                )
+                                                context.startActivity(intent)
+                                            }
+                                        }
+                                    }
+                                },
+                                modifier = Modifier
+                                    .fillMaxWidth()
+                                    .height(ButtonDefaults.MediumContainerHeight),
+                            ) {
+                                Text(
+                                    text = "Connect with Amber",
+                                    style = MaterialTheme.typography.titleMedium,
+                                )
+                            }
+                            Spacer(modifier = Modifier.size(8.dp))
+                            TextButton(
                                 onClick = { navigator.navigate(Screen.Import) },
                                 modifier = Modifier
                                     .fillMaxWidth()

shared/src/commonMain/kotlin/su/reya/coop/ExternalSignerHandler.kt

@@ -1,5 +1,7 @@
 package su.reya.coop
 
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.json.Json
 import rust.nostr.sdk.PublicKey
 import rust.nostr.sdk.UnsignedEvent
 
@@ -9,7 +11,7 @@ import rust.nostr.sdk.UnsignedEvent
  */
 interface ExternalSignerHandler {
     fun isAvailable(): Boolean
-
+    fun setPackageName(packageName: String)
     suspend fun getPublicKey(permissions: String? = null): ExternalSignerResult?
     suspend fun signEvent(event: UnsignedEvent, currentUser: PublicKey): String?
     suspend fun nip04Encrypt(plaintext: String, pubkey: PublicKey): String?
@@ -18,7 +20,25 @@ interface ExternalSignerHandler {
     suspend fun nip44Decrypt(ciphertext: String, pubkey: PublicKey, currentUser: PublicKey): String?
 }
 
+@Serializable
+data class SignerPermission(
+    val type: String,
+    val kind: Int? = null,
+)
+
+object SignerPermissions {
+    fun signEvent(kind: Int? = null) = SignerPermission(type = "sign_event", kind = kind)
+    fun nip04Encrypt() = SignerPermission(type = "nip04_encrypt")
+    fun nip04Decrypt() = SignerPermission(type = "nip04_decrypt")
+    fun nip44Encrypt() = SignerPermission(type = "nip44_encrypt")
+    fun nip44Decrypt() = SignerPermission(type = "nip44_decrypt")
+
+    fun toJson(permissions: List<SignerPermission>): String {
+        return Json.encodeToString(permissions)
+    }
+}
+
 data class ExternalSignerResult(
-    val pubkey: String,
+    val pubkey: PublicKey,
     val packageName: String,
 )

shared/src/commonMain/kotlin/su/reya/coop/ExternalSignerProxy.kt

@@ -7,7 +7,6 @@ import rust.nostr.sdk.UnsignedEvent
 
 class ExternalSignerProxy(
     private val handler: ExternalSignerHandler,
-    private val packageName: String,
     private val currentUser: PublicKey,
 ) : AsyncNostrSigner {
     override suspend fun getPublicKeyAsync(): PublicKey {

shared/src/commonMain/kotlin/su/reya/coop/NostrViewModel.kt

@@ -372,33 +372,6 @@ class NostrViewModel(
         return keys
     }
 
-    private suspend fun createSigner(secret: String): AsyncNostrSigner {
-        return when {
-            secret.startsWith("nsec1") -> Keys.parse(secret)
-
-            secret.startsWith("bunker://") -> {
-                val appKeys = getOrInitAppKeys()
-                val bunker = NostrConnectUri.parse(secret)
-                val timeout = 50.seconds // or Duration.parse("50s")
-                NostrConnect(uri = bunker, appKeys, timeout, null)
-            }
-
-            secret.startsWith("nip55://") -> {
-                val handler = externalSignerHandler
-                    ?: throw IllegalStateException("External signer not available on this platform")
-
-                // Format: nip55://packageName/hexPubkey
-                val parts = secret.removePrefix("nip55://").split("/", limit = 2)
-                val packageName = parts[0]
-                val pubkey = PublicKey.parse(parts[1])
-
-                ExternalSignerProxy(handler, packageName, pubkey)
-            }
-
-            else -> throw IllegalArgumentException("Invalid secret format")
-        }
-    }
-
     private suspend fun blossomUpload(file: ByteArray, contentType: String): String? {
         try {
             // Upload picture to Blossom
@@ -471,6 +444,34 @@ class NostrViewModel(
         }
     }
 
+    private suspend fun createSigner(secret: String): AsyncNostrSigner {
+        return when {
+            secret.startsWith("nsec1") -> Keys.parse(secret)
+
+            secret.startsWith("bunker://") -> {
+                val appKeys = getOrInitAppKeys()
+                val bunker = NostrConnectUri.parse(secret)
+                val timeout = 50.seconds // or Duration.parse("50s")
+                NostrConnect(uri = bunker, appKeys, timeout, null)
+            }
+
+            secret.startsWith("nip55://") -> {
+                val handler = externalSignerHandler
+                    ?: throw IllegalStateException("External signer not available on this platform")
+
+                // Format: nip55://packageName/hexPubkey
+                val parts = secret.removePrefix("nip55://").split("/", limit = 2)
+                val packageName = parts[0]
+                val pubkey = PublicKey.parse(parts[1])
+
+                handler.setPackageName(packageName)
+                ExternalSignerProxy(handler, pubkey)
+            }
+
+            else -> throw IllegalArgumentException("Invalid secret format")
+        }
+    }
+
     suspend fun verifyIdentity(secret: String): PublicKey? {
         try {
             val signer = createSigner(secret)
@@ -498,6 +499,39 @@ class NostrViewModel(
         }
     }
 
+    suspend fun connectExternalSigner() {
+        val handler = externalSignerHandler ?: throw IllegalStateException("Signer not available")
+        _isLoggedIn.value = true
+        try {
+            val permissions = SignerPermissions.toJson(
+                listOf(
+                    SignerPermissions.signEvent(),
+                    SignerPermissions.nip04Encrypt(),
+                    SignerPermissions.nip04Decrypt(),
+                    SignerPermissions.nip44Encrypt(),
+                    SignerPermissions.nip44Decrypt(),
+                )
+            )
+            val result = handler.getPublicKey(permissions) ?: throw Exception("Rejected")
+            val signer = ExternalSignerProxy(handler, result.pubkey)
+
+            // Update signer
+            nostr.setSigner(signer)
+
+            // Store the signer in the secret storage
+            secretStore.set("user_signer", "nip55://${result.packageName}/${result.pubkey.toHex()}")
+        } catch (e: Exception) {
+            showError("Error: ${e.message}")
+        } finally {
+            _signerRequired.value = false
+            _isLoggedIn.value = false
+        }
+    }
+
+    fun isExternalSignerAvailable(): Boolean {
+        return externalSignerHandler?.isAvailable() == true
+    }
+
     suspend fun useDefaultMsgRelayList() {
         try {
             val defaultRelays = nostr.getDefaultMsgRelayList()