# ChatPanel Unification Design

**Date:** 2026-04-03

## Goal

Replace the four divergent chat surfaces (ChatView, BriefingView, WorkspaceView, HomeView widget) with a single `ChatPanel` component that encapsulates all chat behaviour — streaming, TTS, PTT, tool calls, thinking blocks, abort — so that fixes and features automatically apply to every context.

---

## Background

The app currently has four independent chat implementations that have drifted significantly:

| Surface | File | Gap |
|---|---|---|
| Main chat | `ChatView.vue` | Canonical reference |
| Briefing | `BriefingView.vue` | Had separate TTS impl (now fixed), no PTT, streaming race bug |
| Workspace | `WorkspaceView.vue` | TTS missing until recently, different input wiring |
| Dashboard widget | `HomeView.vue` + `DashboardChatInput.vue` | Separate input component, response rendered manually in parent, no TTS, no PTT |

Every fix to chat has required touching 3–4 files. This design makes chat a first-class component.

---

## Architecture

### Component: `ChatPanel.vue`

A single Vue 3 component that owns the entire chat interaction loop for a given conversation context. Two variants controlled by a `variant` prop:

- **`full`** — full-height chat: message history, streaming bubble, input bar, all controls
- **`widget`** — compact embedded chat: input bar + compact response area, no history scroll

Both variants share identical internals: same composables, same store reads, same TTS/PTT/abort logic.

### Extracted Sub-components

| Component | Responsibility |
|---|---|
| `ChatInputBar.vue` | Unified input bar: textarea, note picker, PTT mic, send button, abort button |
| `ChatMessageList.vue` | Scrollable message history with auto-scroll, bulk-select (full variant only) |
| `ChatStreamingBubble.vue` | Live streaming content display + thinking block |
| `ChatToolCallList.vue` | Tool call cards, collapsed/expanded state |

### State Ownership

`ChatPanel` reads from `useChatStore` directly — it does not accept messages or streaming state as props. This mirrors how all current views work and avoids prop-drilling re-implementation.

The conversation being displayed is controlled via a `convId` prop. When `convId` is undefined, `ChatPanel` uses `chatStore.currentConversationId`. The parent view sets up the conversation (creates it if needed) and passes the ID down.

---

## Props & Emits Interface

```typescript
interface ChatPanelProps {
  variant: 'full' | 'widget'
  convId?: number                  // which conversation to display; undefined = store current
  projectId?: number               // workspace: pins RAG scope, passed to sendMessage
  briefingMode?: boolean           // briefing: hides RAG scope chip, enables briefing-specific send path
  placeholder?: string             // input placeholder text
  autoFocus?: boolean              // focus input on mount
}

interface ChatPanelEmits {
  // Emitted when a new conversation is started from the widget (so parent can track convId)
  (e: 'conversation-started', convId: number): void
}
```

All other behaviour (TTS, PTT, thinking, tool calls, streaming indicator, abort) is always on — not gated by props. The intentional differences between views are expressed only through the props above.

---

## Variant Behaviour

### `variant="full"` (ChatView, BriefingView, WorkspaceView)

Layout (top to bottom):
```
┌────────────────────────────────────────┐
│ [RAG scope chip / briefing header]     │  ← shown unless briefingMode or projectId set
│ ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ │
│ ChatMessageList                        │
│   user bubble                          │
│   assistant bubble + tool calls        │
│   thinking block (always shown)        │
│   ...                                  │
│ ChatStreamingBubble (while streaming)  │
│ ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ │
│ ChatInputBar                           │
│   [textarea] [note-picker] [mic] [▶]  │
│   [listen toggle] [abort]              │
└────────────────────────────────────────┘
```

### `variant="widget"` (HomeView dashboard)

Layout (top to bottom, compact):
```
┌────────────────────────────────────────┐
│ ChatInputBar (pill style)              │
│   [textarea] [mic] [▶]                │
├────────────────────────────────────────┤
│ [query text]              (after send) │
│ [streaming / final response text]      │
│ [tool call chips]                      │
│ [Continue in Chat →]                  │
└────────────────────────────────────────┘
```

The widget variant does NOT show full message history. It shows only the most recent exchange. Once a new conversation is started or the user navigates to `/chat/:id`, the full history is available.

The `.dashboard-response` section currently in `HomeView.vue` moves inside `ChatPanel` and is rendered when `variant="widget"` and a conversation exists.

---

## TTS / PTT Wiring

`ChatPanel` instantiates `useStreamingTts` and `useListenMode` internally. These are not passed as props.

```typescript
// Inside ChatPanel setup()
const listenMode = useListenMode()
const voiceTtsEnabled = computed(() => /* same check as current views */)
const tts = useStreamingTts({
  streamingContent: computed(() => chatStore.streamingContent),
  streaming: computed(() => !!chatStore.streaming),
  enabled: computed(() => listenMode.value && voiceTtsEnabled.value),
})
```

PTT is handled inside `ChatInputBar` via the existing `useVoiceRecorder` composable (already used in `DashboardChatInput`). On recording stop, the transcribed text is placed in the textarea and auto-submitted.

---

## Per-View Migration

### ChatView → `<ChatPanel variant="full">`
- Remove: all TTS/PTT/streaming/abort logic, scroll management, input bar template
- Keep: route wiring, conversation list sidebar, bulk-delete UI (sidebar stays in ChatView)
- ChatPanel replaces only the right-hand panel

### BriefingView → `<ChatPanel variant="full" briefingMode />`
- Remove: streaming watch, TTS, manual scroll, input bar, response persistence workaround
- Keep: history dropdown (today / past briefings), date header
- `briefingMode` hides the RAG scope chip

### WorkspaceView → `<ChatPanel variant="full" :projectId="projectId">`
- Remove: inline chat input, streaming watch, TTS wiring
- Keep: 3-panel grid layout, task panel, note editor panel
- ChatPanel takes the centre column

### HomeView → `<ChatPanel variant="widget">`
- Remove: `DashboardChatInput` import + usage, `.dashboard-response` section, all manual store wiring (`dashboardConvId`, `dashboardQuery`, `dashboardFinalContent`, `dashboardFinalToolCalls`, `onChatSubmit`)
- Keep: dashboard layout, projects/tasks/events sections
- `DashboardChatInput.vue` deleted

---

## Data Flow

```
Parent view
  └─ <ChatPanel :convId="convId" variant="full|widget">
       ├─ reads: useChatStore (messages, streaming, streamingContent, currentConversation)
       ├─ ChatMessageList — renders history from store
       ├─ ChatStreamingBubble — renders chatStore.streamingContent while streaming
       ├─ ChatToolCallList — renders tool calls from streaming + finalized messages
       ├─ ChatInputBar
       │    ├─ usePtt (mic → textarea → auto-send)
       │    └─ emits: submit(content, contextNoteId)
       ├─ useStreamingTts (sentence-chunk TTS during streaming)
       └─ useListenMode (shared global toggle)
```

---

## Files Created / Modified

**Created:**
- `frontend/src/components/ChatPanel.vue`
- `frontend/src/components/ChatInputBar.vue`
- `frontend/src/components/ChatMessageList.vue`
- `frontend/src/components/ChatStreamingBubble.vue`
- (no new composable needed — PTT uses existing `useVoiceRecorder.ts`)

**Modified:**
- `frontend/src/views/ChatView.vue` — use ChatPanel for the chat area
- `frontend/src/views/BriefingView.vue` — replace chat section with ChatPanel
- `frontend/src/views/WorkspaceView.vue` — replace inline chat with ChatPanel
- `frontend/src/views/HomeView.vue` — replace DashboardChatInput + response section with ChatPanel widget

**Deleted:**
- `frontend/src/components/DashboardChatInput.vue`

---

## CSS / Styling

- `ChatPanel` carries its own scoped CSS for both variants
- `ChatInputBar` replicates the pill style currently in `DashboardChatInput` and the flat style in `ChatView` — variant is controlled by a `pill` boolean prop (default false; widget sets it true)
- All existing UI design language tokens (`--color-primary`, `--radius-lg`, Fraunces labels, gradient send button) are preserved

---

## What Does NOT Change

- Chat store (`useChatStore`) — unchanged
- API client (`client.ts`) — unchanged
- Backend routes — unchanged
- WorkspaceTaskPanel and WorkspaceNoteEditor — unchanged
- Briefing history dropdown and date header — unchanged
- ChatView conversation sidebar and bulk-delete — unchanged
- RAG scope chip logic — moved inside ChatPanel, behaviour identical
