feat(chat): show agent message reactions (#1422)

app/src/test/java/com/m57/hermescontrol/data/ws/EventParserTest.kt

@@ -1,5 +1,6 @@
 package com.m57.hermescontrol.data.ws
 
+import com.m57.hermescontrol.data.model.MessageReaction
 import io.mockk.every
 import io.mockk.mockkStatic
 import io.mockk.unmockkAll
@@ -928,6 +929,52 @@ class EventParserTest {
         )
     }
 
+    @Test
+    fun testParseMessageReaction_returnsMessageReactionUpdated() {
+        val response =
+            createJsonRpcResponse(
+                jsonrpc = "2.0",
+                id = null,
+                result = null,
+                error = null,
+                method = "event",
+                params =
+                    mapOf(
+                        "type" to "message.reaction",
+                        "session_id" to "s1",
+                        "payload" to
+                            mapOf(
+                                "row_id" to 42,
+                                "role" to "user",
+                                "reactions" to
+                                    listOf(
+                                        mapOf("emoji" to "\uD83D\uDE02", "author" to "agent", "at" to 1.0),
+                                        mapOf("emoji" to "", "author" to "user"),
+                                    ),
+                            ),
+                    ),
+            )
+        val event = EventParser.parse(response, "") as WsEvent.MessageReactionUpdated
+        assertEquals(42L, event.rowId)
+        assertEquals("user", event.role)
+        assertEquals("s1", event.sessionId)
+        assertEquals(listOf(MessageReaction("\uD83D\uDE02", "agent")), event.reactions)
+    }
+
+    @Test
+    fun testParseMessageReaction_withoutRowId_isUnknown() {
+        val response =
+            createJsonRpcResponse(
+                jsonrpc = "2.0",
+                id = null,
+                result = null,
+                error = null,
+                method = "event",
+                params = mapOf("type" to "message.reaction", "payload" to mapOf("reactions" to emptyList<Any>())),
+            )
+        assertTrue(EventParser.parse(response, "") is WsEvent.Unknown)
+    }
+
     @Test
     fun testParseUnknownType_returnsUnknownEvent() {
         val response =

app/src/test/java/com/m57/hermescontrol/ui/chat/ChatServerMessageMapperPurityTest.kt

@@ -1,8 +1,12 @@
 package com.m57.hermescontrol.ui.chat
 
+import com.m57.hermescontrol.data.model.MessageReaction
 import com.m57.hermescontrol.data.model.SessionMessage
 import com.m57.hermescontrol.notification.ReplyNotificationTarget
 import kotlinx.serialization.json.JsonPrimitive
+import kotlinx.serialization.json.buildJsonArray
+import kotlinx.serialization.json.buildJsonObject
+import kotlinx.serialization.json.put
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertNull
 import org.junit.Test
@@ -59,4 +63,35 @@ class ChatServerMessageMapperPurityTest {
 
         assertEquals(42L, mapped.single().timestamp)
     }
+
+    @Test
+    fun persistedReactionsHydrateFromDisplayMetadata() {
+        val row =
+            SessionMessage(
+                id = 5,
+                role = "user",
+                content = JsonPrimitive("hello"),
+                display_metadata =
+                    buildJsonObject {
+                        put(
+                            "reactions",
+                            buildJsonArray {
+                                add(
+                                    buildJsonObject {
+                                        put("emoji", "\uD83D\uDE02")
+                                        put("author", "agent")
+                                    },
+                                )
+                                add(buildJsonObject { put("author", "user") })
+                            },
+                        )
+                    },
+            )
+        val mapped = mapServerMessages("s", listOf(row), 0, true, emptyList()).single()
+        assertEquals(listOf(MessageReaction("\uD83D\uDE02", "agent")), mapped.reactions)
+        assertEquals(
+            emptyList<MessageReaction>(),
+            mapServerMessages("s", listOf(assistant(6, "x")), 0, true, emptyList()).single().reactions,
+        )
+    }
 }

app/src/test/java/com/m57/hermescontrol/ui/chat/ChatWsEventReducerTest.kt

@@ -1,5 +1,6 @@
 package com.m57.hermescontrol.ui.chat
 
+import com.m57.hermescontrol.data.model.MessageReaction
 import com.m57.hermescontrol.data.model.UsageSnapshotResponse
 import com.m57.hermescontrol.data.ws.WsEvent
 import org.junit.Assert.assertEquals
@@ -1642,4 +1643,60 @@ class ChatWsEventReducerTest {
         assertEquals("idle", result.state.compressionStatus)
         assertEquals(initialMessages, result.state.messages)
     }
+
+    @Test
+    fun messageReactionPaintsOnlyTheRowWithTheMatchingServerId() {
+        val target = ChatMessage(id = "a", role = MessageRole.USER, content = "hi", serverRowId = 7L)
+        val other = ChatMessage(id = "b", role = MessageRole.ASSISTANT, content = "yo", serverRowId = 8L)
+        val state = ChatUiState(currentSessionId = "s", messages = listOf(target, other))
+        val reactions = listOf(MessageReaction("\u2764\uFE0F", "agent"))
+        val result =
+            ChatWsEventReducer.reduce(
+                state,
+                StreamingState(),
+                WsEvent.MessageReactionUpdated(7L, reactions, "user", "s"),
+                "s",
+            )
+        assertEquals(reactions, result.state.messages[0].reactions)
+        assertTrue(
+            result.state.messages[1]
+                .reactions
+                .isEmpty(),
+        )
+        val retracted =
+            ChatWsEventReducer.reduce(
+                result.state,
+                result.streamingState,
+                WsEvent.MessageReactionUpdated(7L, emptyList(), "user", "s"),
+                "s",
+            )
+        assertTrue(
+            retracted.state.messages[0]
+                .reactions
+                .isEmpty(),
+        )
+    }
+
+    @Test
+    fun messageReactionForUnknownRowOrOtherSessionIsIgnored() {
+        val msg = ChatMessage(id = "a", role = MessageRole.USER, content = "hi", serverRowId = 7L)
+        val state = ChatUiState(currentSessionId = "s", messages = listOf(msg))
+        val reactions = listOf(MessageReaction("\uD83D\uDC4D", "agent"))
+        val unknownRow =
+            ChatWsEventReducer.reduce(
+                state,
+                StreamingState(),
+                WsEvent.MessageReactionUpdated(99L, reactions, "user", "s"),
+                "s",
+            )
+        assertEquals(state, unknownRow.state)
+        val otherSession =
+            ChatWsEventReducer.reduce(
+                state,
+                StreamingState(),
+                WsEvent.MessageReactionUpdated(7L, reactions, "user", "zzz"),
+                "s",
+            )
+        assertEquals(state, otherSession.state)
+    }
 }