feat(#525): render reasoning.delta / reasoning.available stream (#543)

* feat(#525): add ReasoningDelta + ReasoningAvailable WsEvent types

* feat(#525): parse reasoning.delta + reasoning.available; route through reducer + StreamingState

* feat(#525): add reasoning streaming buffer to ChatStreamingController

* feat(#525): dispatch ReasoningDelta/ReasoningAvailable in ChatViewModel

* feat(#525): render collapsible ReasoningIndicator in chat list

* fix(#525): address review — icons+semantics, LocalHermesStatusColors, drop redundant ReasoningAvailable branch

* feat(#525): persist reasoningText on model, entity, mapper + Room migration 3->4

* feat(#525): reducer + streaming carry reasoningText onto message

* feat(#525): render persisted reasoning above each assistant bubble, drop global indicator

* nix: flake

* nix: flake

---------

Co-authored-by: M57 <m57@hermes-control.app>

app/src/main/java/com/m57/hermescontrol/data/local/ChatMessageEntity.kt

@@ -28,6 +28,8 @@ data class ChatMessageEntity(
     val role: String,
     @ColumnInfo(name = "content")
     val content: String,
+    @ColumnInfo(name = "reasoning_text")
+    val reasoningText: String = "",
     @ColumnInfo(name = "timestamp")
     val timestamp: Long,
     @ColumnInfo(name = "tool_name")

app/src/main/java/com/m57/hermescontrol/data/local/ChatMessageMapper.kt

@@ -22,6 +22,7 @@ fun ChatMessageEntity.toUiModel(): ChatMessage =
                 else -> MessageRole.ASSISTANT
             },
         content = content,
+        reasoningText = reasoningText,
         timestamp = timestamp,
         isStreaming = isStreaming,
         toolName = toolName,
@@ -40,6 +41,7 @@ fun ChatMessage.toEntity(sessionId: String): ChatMessageEntity =
         sessionId = sessionId,
         role = role.name,
         content = content,
+        reasoningText = reasoningText,
         timestamp = timestamp,
         toolName = toolName,
         toolStatus = toolStatus?.name,

app/src/main/java/com/m57/hermescontrol/data/local/HermesDatabase.kt

@@ -11,7 +11,7 @@ import java.io.File
 
 @Database(
     entities = [ChatMessageEntity::class],
-    version = 3,
+    version = 4,
     exportSchema = true,
 )
 abstract class HermesDatabase : RoomDatabase() {
@@ -45,13 +45,22 @@ abstract class HermesDatabase : RoomDatabase() {
                         }
                     }
 
+                val migration3to4 =
+                    object : Migration(3, 4) {
+                        override fun migrate(db: SupportSQLiteDatabase) {
+                            db.execSQL(
+                                "ALTER TABLE `chat_messages` ADD COLUMN `reasoning_text` TEXT NOT NULL DEFAULT ''",
+                            )
+                        }
+                    }
+
                 instance ?: Room
                     .databaseBuilder(
                         context.applicationContext,
                         HermesDatabase::class.java,
                         "hermes_control.db",
                     ).openHelperFactory(factory)
-                    .addMigrations(migration2to3)
+                    .addMigrations(migration2to3, migration3to4)
                     .fallbackToDestructiveMigration(false)
                     .build()
                     .also { instance = it }

app/src/main/java/com/m57/hermescontrol/data/ws/EventParser.kt

@@ -62,6 +62,15 @@ object EventParser {
                 WsEvent.ThinkingDelta(token, sessionId)
             }
 
+            "reasoning.delta" -> {
+                val token = payload?.get("text") as? String ?: ""
+                WsEvent.ReasoningDelta(token, sessionId)
+            }
+
+            "reasoning.available" -> {
+                WsEvent.ReasoningAvailable(sessionId)
+            }
+
             "message.complete" -> {
                 val text = payload?.get("text") as? String ?: ""
                 WsEvent.MessageComplete(text, sessionId)

app/src/main/java/com/m57/hermescontrol/data/ws/WsEvent.kt

@@ -30,6 +30,15 @@ sealed class WsEvent {
         val sessionId: String?,
     ) : WsEvent()
 
+    data class ReasoningDelta(
+        val token: String,
+        val sessionId: String?,
+    ) : WsEvent()
+
+    data class ReasoningAvailable(
+        val sessionId: String?,
+    ) : WsEvent()
+
     data class MessageComplete(
         val text: String,
         val sessionId: String?,

app/src/main/java/com/m57/hermescontrol/ui/chat/ChatMessage.kt

@@ -18,6 +18,7 @@ data class ChatMessage(
     val id: String = UUID.randomUUID().toString(),
     val role: MessageRole,
     val content: String,
+    val reasoningText: String = "",
     val timestamp: Long = System.currentTimeMillis(),
     val isStreaming: Boolean = false,
     val toolName: String? = null,

app/src/main/java/com/m57/hermescontrol/ui/chat/ChatScreen.kt

@@ -18,6 +18,7 @@ import androidx.compose.foundation.BorderStroke
 import androidx.compose.foundation.ExperimentalFoundationApi
 import androidx.compose.foundation.background
 import androidx.compose.foundation.border
+import androidx.compose.foundation.clickable
 import androidx.compose.foundation.combinedClickable
 import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.foundation.layout.Arrangement
@@ -51,11 +52,14 @@ import androidx.compose.material.icons.automirrored.filled.Send
 import androidx.compose.material.icons.filled.Add
 import androidx.compose.material.icons.filled.AttachFile
 import androidx.compose.material.icons.filled.Close
+import androidx.compose.material.icons.filled.ExpandLess
+import androidx.compose.material.icons.filled.ExpandMore
 import androidx.compose.material.icons.filled.KeyboardArrowDown
 import androidx.compose.material.icons.filled.KeyboardArrowUp
 import androidx.compose.material.icons.filled.Mic
 import androidx.compose.material.icons.filled.Search
 import androidx.compose.material.icons.filled.Stop
+import androidx.compose.material.icons.outlined.Psychology
 import androidx.compose.material3.AlertDialog
 import androidx.compose.material3.ButtonDefaults
 import androidx.compose.material3.Card
@@ -520,7 +524,7 @@ private fun ThinkingIndicator(thinkingText: String) {
         Card(
             colors =
                 CardDefaults.cardColors(
-                    containerColor = MaterialTheme.colorScheme.surfaceVariant.copy(alpha = 0.5f),
+                    containerColor = LocalHermesStatusColors.current.infoContainer.copy(alpha = 0.5f),
                 ),
             shape = RoundedCornerShape(12.dp),
         ) {
@@ -544,7 +548,7 @@ private fun ThinkingIndicator(thinkingText: String) {
                         },
                     style =
                         MaterialTheme.typography.bodySmall.copy(
-                            color = MaterialTheme.colorScheme.onSurfaceVariant,
+                            color = LocalHermesStatusColors.current.info,
                         ),
                     maxLines = 2,
                     modifier = Modifier.animateContentSize(),
@@ -554,6 +558,62 @@ private fun ThinkingIndicator(thinkingText: String) {
     }
 }
 
+@Composable
+private fun ReasoningIndicator(reasoningText: String) {
+    var expanded by remember { mutableStateOf(false) }
+    val statusColors = LocalHermesStatusColors.current
+    Card(
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .padding(horizontal = 12.dp, vertical = 4.dp)
+                .clickable(
+                    role = Role.Button,
+                    onClick = { expanded = !expanded },
+                ),
+        colors =
+            CardDefaults.cardColors(
+                containerColor = statusColors.infoContainer.copy(alpha = 0.5f),
+            ),
+        shape = RoundedCornerShape(12.dp),
+    ) {
+        Column(modifier = Modifier.padding(horizontal = 12.dp, vertical = 8.dp)) {
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                Icon(
+                    imageVector = Icons.Outlined.Psychology,
+                    contentDescription = stringResource(R.string.chat_reasoning),
+                    tint = statusColors.info,
+                    modifier = Modifier.size(18.dp),
+                )
+                Spacer(Modifier.width(8.dp))
+                Text(
+                    text = stringResource(R.string.chat_reasoning),
+                    style = MaterialTheme.typography.labelMedium,
+                    color = statusColors.info,
+                )
+                Spacer(Modifier.weight(1f))
+                Icon(
+                    imageVector = if (expanded) Icons.Filled.ExpandLess else Icons.Filled.ExpandMore,
+                    contentDescription =
+                        stringResource(
+                            if (expanded) R.string.chat_reasoning_collapse else R.string.chat_reasoning_expand,
+                        ),
+                    tint = statusColors.info,
+                    modifier = Modifier.size(18.dp),
+                )
+            }
+            AnimatedVisibility(visible = expanded) {
+                Text(
+                    text = reasoningText,
+                    style = MaterialTheme.typography.bodySmall,
+                    color = statusColors.info,
+                    modifier = Modifier.padding(top = 4.dp),
+                )
+            }
+        }
+    }
+}
+
 @Composable
 private fun ChatInputBar(
     inputText: String,
@@ -1649,6 +1709,10 @@ private fun ChatMessageList(
                 val isLastMessage = index == messages.lastIndex
                 val isAssistant = message.role == MessageRole.ASSISTANT
 
+                if (isAssistant && message.reasoningText.isNotBlank()) {
+                    ReasoningIndicator(message.reasoningText)
+                }
+
                 if (typingEffectEnabled && isLastMessage && isAssistant && message.isStreaming &&
                     lastAnimatedMessageId != message.id
                 ) {
@@ -1674,6 +1738,9 @@ private fun ChatMessageList(
             // Streaming message
             streamingMessage?.let { streaming ->
                 item(key = "streaming-${streaming.id}") {
+                    if (streaming.reasoningText.isNotBlank()) {
+                        ReasoningIndicator(streaming.reasoningText)
+                    }
                     if (typingEffectEnabled && streaming.isStreaming) {
                         StreamingBubbleWithTypingEffect(
                             streaming = streaming,

app/src/main/java/com/m57/hermescontrol/ui/chat/ChatStreamingController.kt

@@ -33,6 +33,9 @@ class ChatStreamingController(
     private val thinkingBuffer = java.lang.StringBuilder()
     private var lastThinkingFlushMs = 0L
 
+    private val reasoningBuffer = java.lang.StringBuilder()
+    private var lastReasoningFlushMs = 0L
+
     /**
      * Resets all streaming buffers. Centralizes the clear logic that was
      * previously scattered across MessageStart, MessageComplete, MessageDone,
@@ -41,8 +44,10 @@ class ChatStreamingController(
     fun resetStreaming() {
         streamingBuffer.clear()
         thinkingBuffer.clear()
+        reasoningBuffer.clear()
         lastFlushMs = 0L
         lastThinkingFlushMs = 0L
+        lastReasoningFlushMs = 0L
     }
 
     /** Resets buffers and starts a fresh streaming message (called on MessageStart). */
@@ -109,4 +114,26 @@ class ChatStreamingController(
             }
         }
     }
+
+    fun handleReasoningDelta(event: WsEvent.ReasoningDelta) {
+        if (!isCurrentSession(event.sessionId)) return
+
+        reasoningBuffer.append(event.token)
+        val now = System.currentTimeMillis()
+
+        // Always flush in tests, or if enough time has passed
+        val shouldFlush =
+            (now - lastReasoningFlushMs >= 33L) || lastReasoningFlushMs == 0L || isTestEnvironment()
+        if (shouldFlush) {
+            val currentContent = reasoningBuffer.toString()
+            lastReasoningFlushMs = now
+            streamingState.update { state ->
+                state.copy(
+                    isReasoning = true,
+                    reasoningText = currentContent,
+                    streamingMessage = state.streamingMessage?.copy(reasoningText = currentContent),
+                )
+            }
+        }
+    }
 }

app/src/main/java/com/m57/hermescontrol/ui/chat/ChatViewModel.kt

@@ -311,6 +311,10 @@ class ChatViewModel(
                 streamingController.handleThinkingDelta(event)
             }
 
+            is WsEvent.ReasoningDelta -> {
+                streamingController.handleReasoningDelta(event)
+            }
+
             is WsEvent.MessageStart -> {
                 streamingController.beginStreamingMessage()
             }

app/src/main/java/com/m57/hermescontrol/ui/chat/ChatWsEventReducer.kt

@@ -27,6 +27,7 @@ object ChatWsEventReducer {
                 is WsEvent.MessageStart -> event.sessionId
                 is WsEvent.MessageToken -> event.sessionId
                 is WsEvent.ThinkingDelta -> event.sessionId
+                is WsEvent.ReasoningDelta -> event.sessionId
                 is WsEvent.MessageComplete -> event.sessionId
                 is WsEvent.MessageDone -> event.sessionId
                 is WsEvent.ToolStart -> event.sessionId
@@ -53,6 +54,8 @@ object ChatWsEventReducer {
             is WsEvent.MessageToken -> onMessageToken(state, streamingState, event)
 
             is WsEvent.ThinkingDelta -> onThinkingDelta(state, streamingState, event)
+            is WsEvent.ReasoningDelta -> onReasoningDelta(state, streamingState, event)
+            is WsEvent.ReasoningAvailable -> onReasoningAvailable(state, streamingState, event)
 
             is WsEvent.MessageComplete -> onMessageComplete(state, streamingState, event)
 
@@ -163,6 +166,34 @@ object ChatWsEventReducer {
         )
     }
 
+    // ── ReasoningDelta ────────────────────────────────────────────────
+    private fun onReasoningDelta(
+        state: ChatUiState,
+        streamingState: StreamingState,
+        event: WsEvent.ReasoningDelta,
+    ): ReducerResult {
+        val currentContent = streamingState.reasoningText + event.token
+        return ReducerResult(
+            state = state,
+            streamingState =
+                streamingState.copy(
+                    isReasoning = true,
+                    reasoningText = currentContent,
+                ),
+        )
+    }
+
+    // ── ReasoningAvailable ────────────────────────────────────────────
+    private fun onReasoningAvailable(
+        state: ChatUiState,
+        streamingState: StreamingState,
+        event: WsEvent.ReasoningAvailable,
+    ): ReducerResult =
+        ReducerResult(
+            state = state,
+            streamingState = streamingState.copy(isReasoning = true),
+        )
+
     // ── MessageComplete ───────────────────────────────────────────────
 
     private fun onMessageComplete(
@@ -175,9 +206,11 @@ object ChatWsEventReducer {
             streaming?.copy(
                 content = event.text ?: streaming.content,
                 isStreaming = false,
+                reasoningText = streamingState.reasoningText,
             ) ?: ChatMessage(
                 role = MessageRole.ASSISTANT,
                 content = event.text ?: "",
+                reasoningText = streamingState.reasoningText,
             )
         val effects = mutableListOf<ReducerEffect>()
         val sid = state.currentSessionId
@@ -206,7 +239,7 @@ object ChatWsEventReducer {
                 state = state,
                 streamingState = streamingState,
             )
-        val msg = streaming.copy(isStreaming = false)
+        val msg = streaming.copy(isStreaming = false, reasoningText = streamingState.reasoningText)
         val effects = mutableListOf<ReducerEffect>()
         val sid = state.currentSessionId
         if (sid != null) {

app/src/main/java/com/m57/hermescontrol/ui/chat/StreamingState.kt

@@ -4,4 +4,6 @@ data class StreamingState(
     val streamingMessage: ChatMessage? = null,
     val isThinking: Boolean = false,
     val thinkingText: String = "",
+    val isReasoning: Boolean = false,
+    val reasoningText: String = "",
 )