feat(chat): simplify assistant message states (#1131)

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

@@ -1,12 +1,16 @@
 package com.m57.hermescontrol.ui.chat
 
+import com.m57.hermescontrol.R
 import com.m57.hermescontrol.ui.chat.fullbleed.AgentEntry
+import com.m57.hermescontrol.ui.chat.fullbleed.AgentStatus
 import com.m57.hermescontrol.ui.chat.fullbleed.ChatTurn
 import com.m57.hermescontrol.ui.chat.fullbleed.currentMatchMessageId
+import com.m57.hermescontrol.ui.chat.fullbleed.deriveAgentStatus
 import com.m57.hermescontrol.ui.chat.fullbleed.groupIntoTurns
 import com.m57.hermescontrol.ui.chat.fullbleed.groupIntoTurnsWithStreaming
 import com.m57.hermescontrol.ui.chat.fullbleed.matchedMessageIds
 import com.m57.hermescontrol.ui.chat.fullbleed.messageIdToLazyIndex
+import com.m57.hermescontrol.ui.chat.fullbleed.toolStatusLabelRes
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertNull
 import org.junit.Test
@@ -208,6 +212,167 @@ class FullBleedTurnsTest {
         assertEquals(listOf(entries(AgentEntry.Prose(s))), groupIntoTurnsWithStreaming(emptyList(), s))
     }
 
+    // ── deriveAgentStatus ──────────────────────────────────────────────────
+
+    @Test
+    fun `agent typing with no visible content shows dots`() {
+        assertEquals(
+            AgentStatus.Typing,
+            deriveAgentStatus(
+                isAgentTyping = true,
+                streamingState = StreamingState(),
+                messages = emptyList(),
+            ),
+        )
+    }
+
+    @Test
+    fun `reasoning takes precedence over generic typing`() {
+        assertEquals(
+            AgentStatus.Thinking,
+            deriveAgentStatus(
+                isAgentTyping = true,
+                streamingState = StreamingState(isReasoning = true),
+                messages = emptyList(),
+            ),
+        )
+    }
+
+    @Test
+    fun `visible streaming content removes the temporary status`() {
+        val streaming = msg("s1", MessageRole.ASSISTANT, content = "answer", isStreaming = true)
+        assertNull(
+            deriveAgentStatus(
+                isAgentTyping = true,
+                streamingState = StreamingState(streamingMessage = streaming, isThinking = true),
+                messages = emptyList(),
+            ),
+        )
+    }
+
+    @Test
+    fun `stale running tool from a previous turn is ignored`() {
+        val messages =
+            listOf(
+                msg("old-user", MessageRole.USER),
+                msg("old-tool", MessageRole.TOOL, toolStatus = ToolStatus.RUNNING).copy(toolName = "terminal"),
+                msg("old-assistant", MessageRole.ASSISTANT, content = "previous response"),
+                msg("new-user", MessageRole.USER),
+            )
+        assertEquals(
+            AgentStatus.Typing,
+            deriveAgentStatus(
+                isAgentTyping = true,
+                streamingState = StreamingState(),
+                messages = messages,
+            ),
+        )
+    }
+
+    @Test
+    fun `current turn running tool is detected`() {
+        val messages =
+            listOf(
+                msg("old-user", MessageRole.USER),
+                msg("old-tool", MessageRole.TOOL, toolStatus = ToolStatus.COMPLETED).copy(toolName = "terminal"),
+                msg("old-assistant", MessageRole.ASSISTANT, content = "previous response"),
+                msg("new-user", MessageRole.USER),
+                msg("current-tool", MessageRole.TOOL, toolStatus = ToolStatus.RUNNING).copy(toolName = "web_search"),
+            )
+        assertEquals(
+            AgentStatus.Tool("web_search"),
+            deriveAgentStatus(
+                isAgentTyping = true,
+                streamingState = StreamingState(),
+                messages = messages,
+            ),
+        )
+    }
+
+    @Test
+    fun `latest current turn running tool wins`() {
+        val messages =
+            listOf(
+                msg("new-user", MessageRole.USER),
+                msg("done-tool", MessageRole.TOOL, toolStatus = ToolStatus.COMPLETED).copy(toolName = "terminal"),
+                msg("first-running", MessageRole.TOOL, toolStatus = ToolStatus.RUNNING).copy(toolName = "read_file"),
+                msg("latest-running", MessageRole.TOOL, toolStatus = ToolStatus.RUNNING).copy(toolName = "web_search"),
+            )
+        assertEquals(
+            AgentStatus.Tool("web_search"),
+            deriveAgentStatus(
+                isAgentTyping = true,
+                streamingState = StreamingState(),
+                messages = messages,
+            ),
+        )
+    }
+
+    @Test
+    fun `completed current turn tool falls back to dots`() {
+        val messages =
+            listOf(
+                msg("new-user", MessageRole.USER),
+                msg(
+                    "completed-tool",
+                    MessageRole.TOOL,
+                    toolStatus = ToolStatus.COMPLETED,
+                ).copy(toolName = "web_search"),
+            )
+        assertEquals(
+            AgentStatus.Typing,
+            deriveAgentStatus(
+                isAgentTyping = true,
+                streamingState = StreamingState(),
+                messages = messages,
+            ),
+        )
+    }
+
+    @Test
+    fun `timeline marker does not create a new tool-status turn`() {
+        val marker =
+            msg("marker", MessageRole.USER, content = "model changed")
+                .copy(displayKind = "model_switch")
+        val messages =
+            listOf(
+                msg("new-user", MessageRole.USER),
+                marker,
+                msg("current-tool", MessageRole.TOOL, toolStatus = ToolStatus.RUNNING).copy(toolName = "web_search"),
+            )
+        assertEquals(
+            AgentStatus.Tool("web_search"),
+            deriveAgentStatus(
+                isAgentTyping = true,
+                streamingState = StreamingState(),
+                messages = messages,
+            ),
+        )
+    }
+
+    @Test
+    fun `browser tools use browsing label while read_file keeps file label`() {
+        assertEquals(R.string.chat_agent_status_browsing, toolStatusLabelRes("browser_navigate"))
+        assertEquals(R.string.chat_agent_status_browsing, toolStatusLabelRes("web_extract"))
+        assertEquals(R.string.chat_agent_status_reading, toolStatusLabelRes("read_file"))
+    }
+
+    @Test
+    fun `inactive generation ignores even a running historical tool`() {
+        val messages =
+            listOf(
+                msg("old-user", MessageRole.USER),
+                msg("old-tool", MessageRole.TOOL, toolStatus = ToolStatus.RUNNING).copy(toolName = "terminal"),
+            )
+        assertNull(
+            deriveAgentStatus(
+                isAgentTyping = false,
+                streamingState = StreamingState(),
+                messages = messages,
+            ),
+        )
+    }
+
     // ── messageIdToLazyIndex ───────────────────────────────────────────────
 
     @Test
@@ -233,6 +398,19 @@ class FullBleedTurnsTest {
         assertNull(map["t1"])
     }
 
+    @Test
+    fun `lazy index skips empty assistant placeholders`() {
+        val u1 = msg("u1", MessageRole.USER)
+        val placeholder = msg("empty", MessageRole.ASSISTANT, content = "", isStreaming = true)
+        val tool = msg("t1", MessageRole.TOOL)
+        val answer = msg("a1", MessageRole.ASSISTANT, content = "answer")
+        val map = messageIdToLazyIndex(groupIntoTurns(listOf(u1, placeholder, tool, answer)))
+        // user u1 at 0, empty assistant omitted, tool at 1, answer at 2.
+        assertEquals(0, map["u1"])
+        assertEquals(2, map["a1"])
+        assertNull(map["empty"])
+    }
+
     @Test
     fun `lazy index offsets by leading items`() {
         val u1 = msg("u1", MessageRole.USER)