Feature/mentions (#197)

* mention initial implementation

* Message conservation

app/src/main/java/com/bitchat/android/ui/ChatScreen.kt

@@ -64,6 +64,8 @@ fun ChatScreen(viewModel: ChatViewModel) {
     val showSidebar by viewModel.showSidebar.observeAsState(false)
     val showCommandSuggestions by viewModel.showCommandSuggestions.observeAsState(false)
     val commandSuggestions by viewModel.commandSuggestions.observeAsState(emptyList())
+    val showMentionSuggestions by viewModel.showMentionSuggestions.observeAsState(false)
+    val mentionSuggestions by viewModel.mentionSuggestions.observeAsState(emptyList())
     val showAppInfo by viewModel.showAppInfo.observeAsState(false)
     
     var messageText by remember { mutableStateOf(TextFieldValue("")) }
@@ -114,6 +116,7 @@ fun ChatScreen(viewModel: ChatViewModel) {
                 onMessageTextChange = { newText: TextFieldValue ->
                     messageText = newText
                     viewModel.updateCommandSuggestions(newText.text)
+                    viewModel.updateMentionSuggestions(newText.text)
                 },
                 onSend = {
                     if (messageText.text.trim().isNotEmpty()) {
@@ -123,13 +126,22 @@ fun ChatScreen(viewModel: ChatViewModel) {
                 },
                 showCommandSuggestions = showCommandSuggestions,
                 commandSuggestions = commandSuggestions,
-                onSuggestionClick = { suggestion: CommandSuggestion ->
+                showMentionSuggestions = showMentionSuggestions,
+                mentionSuggestions = mentionSuggestions,
+                onCommandSuggestionClick = { suggestion: CommandSuggestion ->
                     val commandText = viewModel.selectCommandSuggestion(suggestion)
                     messageText = TextFieldValue(
                         text = commandText,
                         selection = TextRange(commandText.length)
                     )
                 },
+                onMentionSuggestionClick = { mention: String ->
+                    val mentionText = viewModel.selectMentionSuggestion(mention, messageText.text)
+                    messageText = TextFieldValue(
+                        text = mentionText,
+                        selection = TextRange(mentionText.length)
+                    )
+                },
                 selectedPrivatePeer = selectedPrivatePeer,
                 currentChannel = currentChannel,
                 nickname = nickname,
@@ -202,7 +214,10 @@ private fun ChatInputSection(
     onSend: () -> Unit,
     showCommandSuggestions: Boolean,
     commandSuggestions: List<CommandSuggestion>,
-    onSuggestionClick: (CommandSuggestion) -> Unit,
+    showMentionSuggestions: Boolean,
+    mentionSuggestions: List<String>,
+    onCommandSuggestionClick: (CommandSuggestion) -> Unit,
+    onMentionSuggestionClick: (String) -> Unit,
     selectedPrivatePeer: String?,
     currentChannel: String?,
     nickname: String,
@@ -220,7 +235,18 @@ private fun ChatInputSection(
             if (showCommandSuggestions && commandSuggestions.isNotEmpty()) {
                 CommandSuggestionsBox(
                     suggestions = commandSuggestions,
-                    onSuggestionClick = onSuggestionClick,
+                    onSuggestionClick = onCommandSuggestionClick,
+                    modifier = Modifier.fillMaxWidth()
+                )
+
+                HorizontalDivider(color = colorScheme.outline.copy(alpha = 0.2f))
+            }
+            
+            // Mention suggestions box
+            if (showMentionSuggestions && mentionSuggestions.isNotEmpty()) {
+                MentionSuggestionsBox(
+                    suggestions = mentionSuggestions,
+                    onSuggestionClick = onMentionSuggestionClick,
                     modifier = Modifier.fillMaxWidth()
                 )
 

app/src/main/java/com/bitchat/android/ui/ChatState.kt

@@ -79,6 +79,13 @@ class ChatState {
     private val _commandSuggestions = MutableLiveData<List<CommandSuggestion>>(emptyList())
     val commandSuggestions: LiveData<List<CommandSuggestion>> = _commandSuggestions
     
+    // Mention autocomplete
+    private val _showMentionSuggestions = MutableLiveData(false)
+    val showMentionSuggestions: LiveData<Boolean> = _showMentionSuggestions
+    
+    private val _mentionSuggestions = MutableLiveData<List<String>>(emptyList())
+    val mentionSuggestions: LiveData<List<String>> = _mentionSuggestions
+    
     // Favorites
     private val _favoritePeers = MutableLiveData<Set<String>>(emptySet())
     val favoritePeers: LiveData<Set<String>> = _favoritePeers
@@ -129,6 +136,8 @@ class ChatState {
     fun getShowSidebarValue() = _showSidebar.value ?: false
     fun getShowCommandSuggestionsValue() = _showCommandSuggestions.value ?: false
     fun getCommandSuggestionsValue() = _commandSuggestions.value ?: emptyList()
+    fun getShowMentionSuggestionsValue() = _showMentionSuggestions.value ?: false
+    fun getMentionSuggestionsValue() = _mentionSuggestions.value ?: emptyList()
     fun getFavoritePeersValue() = _favoritePeers.value ?: emptySet()
     fun getPeerSessionStatesValue() = _peerSessionStates.value ?: emptyMap()
     fun getPeerFingerprintsValue() = _peerFingerprints.value ?: emptyMap()
@@ -202,6 +211,14 @@ class ChatState {
     fun setCommandSuggestions(suggestions: List<CommandSuggestion>) {
         _commandSuggestions.value = suggestions
     }
+    
+    fun setShowMentionSuggestions(show: Boolean) {
+        _showMentionSuggestions.value = show
+    }
+    
+    fun setMentionSuggestions(suggestions: List<String>) {
+        _mentionSuggestions.value = suggestions
+    }
 
     fun setFavoritePeers(favorites: Set<String>) {
         val currentValue = _favoritePeers.value ?: emptySet()

app/src/main/java/com/bitchat/android/ui/ChatViewModel.kt

@@ -83,6 +83,8 @@ class ChatViewModel(
     val hasUnreadPrivateMessages = state.hasUnreadPrivateMessages
     val showCommandSuggestions: LiveData<Boolean> = state.showCommandSuggestions
     val commandSuggestions: LiveData<List<CommandSuggestion>> = state.commandSuggestions
+    val showMentionSuggestions: LiveData<Boolean> = state.showMentionSuggestions
+    val mentionSuggestions: LiveData<List<String>> = state.mentionSuggestions
     val favoritePeers: LiveData<Set<String>> = state.favoritePeers
     val peerSessionStates: LiveData<Map<String, String>> = state.peerSessionStates
     val peerFingerprints: LiveData<Map<String, String>> = state.peerFingerprints
@@ -351,6 +353,16 @@ class ChatViewModel(
         return commandProcessor.selectCommandSuggestion(suggestion)
     }
     
+    // MARK: - Mention Autocomplete
+    
+    fun updateMentionSuggestions(input: String) {
+        commandProcessor.updateMentionSuggestions(input, meshService)
+    }
+    
+    fun selectMentionSuggestion(nickname: String, currentText: String): String {
+        return commandProcessor.selectMentionSuggestion(nickname, currentText)
+    }
+    
     // MARK: - BluetoothMeshDelegate Implementation (delegated)
     
     override fun didReceiveMessage(message: BitchatMessage) {

app/src/main/java/com/bitchat/android/ui/CommandProcessor.kt

@@ -380,6 +380,65 @@ class CommandProcessor(
         return "${suggestion.command} "
     }
     
+    // MARK: - Mention Autocomplete
+    
+    fun updateMentionSuggestions(input: String, meshService: Any) {
+        // Check if input contains @ and we're at the end of a word or at the end of input
+        val atIndex = input.lastIndexOf('@')
+        if (atIndex == -1) {
+            state.setShowMentionSuggestions(false)
+            state.setMentionSuggestions(emptyList())
+            return
+        }
+        
+        // Get the text after the @ symbol
+        val textAfterAt = input.substring(atIndex + 1)
+        
+        // If there's a space after @, don't show suggestions
+        if (textAfterAt.contains(' ')) {
+            state.setShowMentionSuggestions(false)
+            state.setMentionSuggestions(emptyList())
+            return
+        }
+        
+        // Get all connected peer nicknames
+        val peerNicknames = try {
+            val method = meshService::class.java.getDeclaredMethod("getPeerNicknames")
+            val peerNicknamesMap = method.invoke(meshService) as? Map<String, String>
+            peerNicknamesMap?.values?.toList() ?: emptyList()
+        } catch (e: Exception) {
+            emptyList()
+        }
+        
+        // Filter nicknames based on the text after @
+        val filteredNicknames = peerNicknames.filter { nickname ->
+            nickname.startsWith(textAfterAt, ignoreCase = true)
+        }.sorted()
+        
+        if (filteredNicknames.isNotEmpty()) {
+            state.setMentionSuggestions(filteredNicknames)
+            state.setShowMentionSuggestions(true)
+        } else {
+            state.setShowMentionSuggestions(false)
+            state.setMentionSuggestions(emptyList())
+        }
+    }
+    
+    fun selectMentionSuggestion(nickname: String, currentText: String): String {
+        state.setShowMentionSuggestions(false)
+        state.setMentionSuggestions(emptyList())
+        
+        // Find the last @ symbol position
+        val atIndex = currentText.lastIndexOf('@')
+        if (atIndex == -1) {
+            return "$currentText@$nickname "
+        }
+        
+        // Replace the text from the @ symbol to the end with the mention
+        val textBeforeAt = currentText.substring(0, atIndex)
+        return "$textBeforeAt@$nickname "
+    }
+    
     // MARK: - Utility Functions (would access mesh service)
     
     private fun getPeerIDForNickname(nickname: String, meshService: Any): String? {

app/src/main/java/com/bitchat/android/ui/InputComponents.kt

@@ -80,6 +80,68 @@ class SlashCommandVisualTransformation : VisualTransformation {
     }
 }
 
+/**
+ * VisualTransformation that styles mentions with background and color
+ * while preserving cursor positioning and click handling
+ */
+class MentionVisualTransformation : VisualTransformation {
+    override fun filter(text: AnnotatedString): TransformedText {
+        val mentionRegex = Regex("@([a-zA-Z0-9_]+)")
+        val annotatedString = buildAnnotatedString {
+            var lastIndex = 0
+            
+            mentionRegex.findAll(text.text).forEach { match ->
+                // Add text before the match
+                if (match.range.first > lastIndex) {
+                    append(text.text.substring(lastIndex, match.range.first))
+                }
+                
+                // Add the styled mention
+                withStyle(
+                    style = SpanStyle(
+                        color = Color(0xFFFF9500), // Orange
+                        fontFamily = FontFamily.Monospace,
+                        fontWeight = FontWeight.SemiBold
+                    )
+                ) {
+                    append(match.value)
+                }
+                
+                lastIndex = match.range.last + 1
+            }
+            
+            // Add remaining text
+            if (lastIndex < text.text.length) {
+                append(text.text.substring(lastIndex))
+            }
+        }
+        
+        return TransformedText(
+            text = annotatedString,
+            offsetMapping = OffsetMapping.Identity
+        )
+    }
+}
+
+/**
+ * VisualTransformation that combines multiple visual transformations
+ */
+class CombinedVisualTransformation(private val transformations: List<VisualTransformation>) : VisualTransformation {
+    override fun filter(text: AnnotatedString): TransformedText {
+        var resultText = text
+        
+        // Apply each transformation in order
+        transformations.forEach { transformation ->
+            resultText = transformation.filter(resultText).text
+        }
+        
+        return TransformedText(
+            text = resultText,
+            offsetMapping = OffsetMapping.Identity
+        )
+    }
+}
+
 
 
 
@@ -118,7 +180,9 @@ fun MessageInput(
                 keyboardActions = KeyboardActions(onSend = { 
                     if (hasText) onSend() // Only send if there's text
                 }),
-                visualTransformation = SlashCommandVisualTransformation(),
+                visualTransformation = CombinedVisualTransformation(
+                    listOf(SlashCommandVisualTransformation(), MentionVisualTransformation())
+                ),
                 modifier = Modifier
                     .fillMaxWidth()
                     .onFocusChanged { focusState ->
@@ -270,3 +334,64 @@ fun CommandSuggestionItem(
         )
     }
 }
+
+@Composable
+fun MentionSuggestionsBox(
+    suggestions: List<String>,
+    onSuggestionClick: (String) -> Unit,
+    modifier: Modifier = Modifier
+) {
+    val colorScheme = MaterialTheme.colorScheme
+    
+    Column(
+        modifier = modifier
+            .background(colorScheme.surface)
+            .border(1.dp, colorScheme.outline.copy(alpha = 0.3f), RoundedCornerShape(4.dp))
+            .padding(vertical = 8.dp)
+    ) {
+        suggestions.forEach { suggestion: String ->
+            MentionSuggestionItem(
+                suggestion = suggestion,
+                onClick = { onSuggestionClick(suggestion) }
+            )
+        }
+    }
+}
+
+@Composable
+fun MentionSuggestionItem(
+    suggestion: String,
+    onClick: () -> Unit
+) {
+    val colorScheme = MaterialTheme.colorScheme
+    
+    Row(
+        modifier = Modifier
+            .fillMaxWidth()
+            .clickable { onClick() }
+            .padding(horizontal = 12.dp, vertical = 3.dp)
+            .background(Color.Gray.copy(alpha = 0.1f)),
+        verticalAlignment = Alignment.CenterVertically
+    ) {
+        Text(
+            text = "@$suggestion",
+            style = MaterialTheme.typography.bodySmall.copy(
+                fontFamily = FontFamily.Monospace,
+                fontWeight = FontWeight.SemiBold
+            ),
+            color = Color(0xFFFF9500), // Orange like mentions
+            fontSize = 11.sp
+        )
+        
+        Spacer(modifier = Modifier.weight(1f))
+        
+        Text(
+            text = "mention",
+            style = MaterialTheme.typography.bodySmall.copy(
+                fontFamily = FontFamily.Monospace
+            ),
+            color = colorScheme.onSurface.copy(alpha = 0.7f),
+            fontSize = 10.sp
+        )
+    }
+}