add connect with amber button

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()