Merge pull request #389 from greenart7c3/claude/mnemonic-account-path-option-fnVSY

Add mnemonic account index support for BIP-39 key derivation

app/src/main/java/com/greenart7c3/nostrsigner/ui/AccountStateViewModel.kt

@@ -74,7 +74,7 @@ class AccountStateViewModel(npub: String?) : ViewModel() {
         tryLoginExistingAccount(route, npub)
     }
 
-    fun isValidKey(key: String, password: String): Pair<KeyPair?, String> {
+    fun isValidKey(key: String, password: String, accountIndex: Long = 0): Pair<KeyPair?, String> {
         try {
             val signer =
                 if (key.startsWith("ncryptsec")) {
@@ -83,7 +83,7 @@ class AccountStateViewModel(npub: String?) : ViewModel() {
                 } else if (key.startsWith("nsec")) {
                     NostrSignerInternal(KeyPair(privKey = key.bechToBytes()))
                 } else if (key.contains(" ") && Nip06().isValidMnemonic(key)) {
-                    val keyPair = KeyPair(privKey = Nip06().privateKeyFromMnemonic(key))
+                    val keyPair = KeyPair(privKey = Nip06().privateKeyFromMnemonic(key, accountIndex))
                     NostrSignerInternal(keyPair)
                 } else {
                     NostrSignerInternal(KeyPair(Hex.decode(key)))

app/src/main/java/com/greenart7c3/nostrsigner/ui/LoginScreen.kt

@@ -833,6 +833,7 @@ fun LoginPage(
     var isMnemonicMode by rememberSaveable { mutableStateOf(false) }
     var mnemonicWordCount by rememberSaveable { mutableIntStateOf(12) }
     var mnemonicWords by remember { mutableStateOf(List(12) { "" }) }
+    var mnemonicAccountIndex by rememberSaveable { mutableIntStateOf(0) }
     val clipboardManager = LocalClipboard.current
 
     Scaffold(
@@ -957,6 +958,28 @@ fun LoginPage(
                                         }
                                     },
                                 )
+
+                                Spacer(modifier = Modifier.height(16.dp))
+
+                                OutlinedTextField(
+                                    modifier = Modifier.fillMaxWidth(),
+                                    shape = RoundedCornerShape(18.dp),
+                                    value = if (mnemonicAccountIndex == 0) "" else mnemonicAccountIndex.toString(),
+                                    onValueChange = { value ->
+                                        mnemonicAccountIndex = value.filter { it.isDigit() }.toIntOrNull() ?: 0
+                                        if (errorMessage.isNotEmpty()) errorMessage = ""
+                                    },
+                                    label = { Text(stringResource(R.string.mnemonic_account_index)) },
+                                    placeholder = { Text("0") },
+                                    supportingText = {
+                                        Text(stringResource(R.string.mnemonic_account_index_description, mnemonicAccountIndex))
+                                    },
+                                    keyboardOptions = KeyboardOptions(
+                                        keyboardType = KeyboardType.Number,
+                                        imeAction = ImeAction.Done,
+                                    ),
+                                    singleLine = true,
+                                )
                             } else {
                                 Text(
                                     stringResource(R.string.setup_amber_with_your_nostr_private_key_you_can_enter_different_versions_nsec_ncryptsec_or_hex_you_can_also_scan_it_from_a_qr_code),
@@ -1161,7 +1184,7 @@ fun LoginPage(
                                         Amber.instance.applicationIOScope.launch {
                                             isLoading = true
                                             try {
-                                                val isValid = accountViewModel.isValidKey(mnemonicStr, "")
+                                                val isValid = accountViewModel.isValidKey(mnemonicStr, "", mnemonicAccountIndex.toLong())
                                                 isLoading = false
                                                 if (isValid.first != null) {
                                                     keyPair = isValid.first!!

app/src/main/java/com/greenart7c3/nostrsigner/ui/components/MnemonicLoginInput.kt

@@ -149,10 +149,12 @@ private fun WordField(
     nextFocusRequester: FocusRequester?,
     imeAction: ImeAction,
 ) {
-    // Tracks the last word that was chosen from the dropdown so we can suppress
-    // the menu after selection (selecting changes `word`, which would otherwise
-    // re-open the menu immediately).
-    var selectedWord by remember { mutableStateOf("") }
+    // `remember(word)` resets this state synchronously whenever `word` changes.
+    // Initialising to `word` when it is already a complete BIP-39 entry
+    // suppresses the dropdown immediately — no async gap — covering both the
+    // paste case (word set externally, onValueChange never called) and the
+    // case where the user finishes typing a valid word.
+    var selectedWord by remember(word) { mutableStateOf(if (word in wordList) word else "") }
 
     val suggestions = remember(word) {
         if (word.length >= 2) {

app/src/main/res/values/strings.xml

@@ -385,6 +385,8 @@
     <string name="mnemonic_12_words">12 words</string>
     <string name="mnemonic_24_words">24 words</string>
     <string name="mnemonic_words_entered">%1$d of %2$d words entered</string>
+    <string name="mnemonic_account_index">Account index</string>
+    <string name="mnemonic_account_index_description">Use a different index if this mnemonic was used to create multiple accounts (m/44\'/1237\'/%1$d\'/0/0)</string>
     <string name="sign_policy">Sign policy</string>
     <string name="handle_application_permissions">How to handle this application permissions?</string>
     <string name="sign_policy_manual_new_app">Manually approve each permission</string>