feat(chat): display completion timestamp beside copy button on assistant message (#1053)

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

@@ -66,6 +66,11 @@ data class ChatMessage(
      * them as centered timeline chips instead of user bubbles.
      */
     val displayKind: String? = null,
+    /**
+     * Timestamp (ms) when the assistant message finished streaming.
+     * When present, rendered at the bottom beside the copy button.
+     */
+    val finishTimestamp: Long? = null,
 )
 
 /**

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

@@ -2665,7 +2665,11 @@ class ChatViewModel(
     private fun sealStreamingMessageIfAny() {
         val streaming = _streamingState.value.streamingMessage ?: return
         if (streaming.content.isBlank() && streaming.reasoningText.isBlank()) return
-        val finalized = streaming.copy(isStreaming = false)
+        val finalized =
+            streaming.copy(
+                isStreaming = false,
+                finishTimestamp = System.currentTimeMillis(),
+            )
         _uiState.update { it.copy(messages = (it.messages + finalized).dedupeById()) }
         val sid = _uiState.value.currentSessionId
         if (sid != null) {

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

@@ -206,7 +206,11 @@ object ChatWsEventReducer {
         var orphan: ChatMessage? = null
         val preState =
             if (streamingState.streamingMessage?.content?.isNotEmpty() == true) {
-                val finalized = streamingState.streamingMessage.copy(isStreaming = false)
+                val finalized =
+                    streamingState.streamingMessage.copy(
+                        isStreaming = false,
+                        finishTimestamp = System.currentTimeMillis(),
+                    )
                 orphan = finalized
                 state.copy(
                     messages = state.messages.upsertById(finalized),
@@ -369,10 +373,12 @@ object ChatWsEventReducer {
                 content = text,
                 isStreaming = false,
                 reasoningText = reasoning,
+                finishTimestamp = System.currentTimeMillis(),
             ) ?: ChatMessage(
                 role = MessageRole.ASSISTANT,
                 content = text,
                 reasoningText = reasoning,
+                finishTimestamp = System.currentTimeMillis(),
             )
         val effects = mutableListOf<ReducerEffect>()
         val sid = state.currentSessionId
@@ -418,7 +424,12 @@ object ChatWsEventReducer {
             } else {
                 streaming.reasoningText
             }
-        val msg = streaming.copy(isStreaming = false, reasoningText = reasoning)
+        val msg =
+            streaming.copy(
+                isStreaming = false,
+                reasoningText = reasoning,
+                finishTimestamp = System.currentTimeMillis(),
+            )
         val effects = mutableListOf<ReducerEffect>()
         val sid = state.currentSessionId
         if (sid != null) {
@@ -481,6 +492,7 @@ object ChatWsEventReducer {
                     streamingState.streamingMessage.copy(
                         isStreaming = false,
                         reasoningText = reasoning,
+                        finishTimestamp = System.currentTimeMillis(),
                     )
                 orphanToPersist = finalized
                 state.copy(

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

@@ -140,20 +140,36 @@ internal fun FullBleedAgentMessage(
         }
 
         if (!message.isStreaming) {
-            IconButton(
-                onClick = {
-                    scope.launch {
-                        clipboard.setClipEntry(ClipEntry(ClipData.newPlainText(null, message.content)))
-                    }
-                    copied = true
-                },
-                modifier = Modifier.size(28.dp).testTag("fullbleed_copy"),
+            Row(
+                verticalAlignment = Alignment.CenterVertically,
             ) {
-                Icon(
-                    imageVector = if (copied) Icons.Filled.Check else Icons.Filled.ContentCopy,
-                    contentDescription = stringResource(R.string.content_desc_copy),
-                    modifier = Modifier.size(14.dp),
-                    tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                IconButton(
+                    onClick = {
+                        scope.launch {
+                            clipboard.setClipEntry(ClipEntry(ClipData.newPlainText(null, message.content)))
+                        }
+                        copied = true
+                    },
+                    modifier = Modifier.size(28.dp).testTag("fullbleed_copy"),
+                ) {
+                    Icon(
+                        imageVector = if (copied) Icons.Filled.Check else Icons.Filled.ContentCopy,
+                        contentDescription = stringResource(R.string.content_desc_copy),
+                        modifier = Modifier.size(14.dp),
+                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                }
+                Spacer(modifier = Modifier.width(4.dp))
+                val finishTime = message.finishTimestamp ?: message.timestamp
+                Text(
+                    text =
+                        com.m57.hermescontrol.ui.chat.formatTimestamp(
+                            finishTime,
+                            DateFormat.is24HourFormat(LocalContext.current),
+                        ),
+                    style = MaterialTheme.typography.labelSmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.7f),
+                    modifier = Modifier.testTag("fullbleed_finish_time"),
                 )
             }
         }