# HANDOFF: Milestone M2 — Client Chat Engine & WebApp UI Integration

> **Agent**: `worker_chat_m2_2`  
> **Parent**: `ea9d395f-60cc-4be9-a3ac-f706d683a6cd` (`orchestrator_8`)  
> **Milestone**: M2 (Client Chat Engine & WebApp UI Integration)  
> **Target Files Modified / Created**:
> - `client/src/chat/ChatManager.ts`
> - `client/webapp/js/ui/chat_ui.js`
> - `client/webapp/index.html`
> - `client/webapp/js/main.js`
> - `tests/unit/test_webapp_chat_ui.py`

---

## 1. OBSERVATION

1. **TypeScript Engine (`client/src/chat/ChatManager.ts`)**:
   - `ClientItemSnapshot` defines `itemUuid`, `itemName`, `rarity`, `element`, `quality`, `itemLevel`, `affixes: ClientItemAffix[]`, `crafterName`, `signature`, and `createdAtMs` matching `proto/chat.proto` (`ItemLinkSnapshot` message).
   - Added `setQueryItemSnapshotCallback` and enhanced `onTappedItemLink` to support fallback asynchronous retrieval when snapshots are not present in local memory.
   - Updated `parseItemTags` regex from `([a-zA-Z0-9]+)` to `([a-zA-Z0-9_-]+)` to support hyphenated and delimited signatures.
   - Verification command `npm run build` in `client/` ran `tsc` and exited cleanly with returncode 0.

2. **Web Client UI Module (`client/webapp/js/ui/chat_ui.js`)**:
   - Implemented as a Native ES Module with exactly 349 lines (strictly adhering to Soft Cap <= 350 lines).
   - Supported all 8 channels: `Thế Giới` (1, 15s cd), `Khu Vực` (2, 3s cd), `Bang Hội` (3, 500ms cd), `Đội Ngũ` (4, 200ms cd), `Mật Thư` (5, 500ms cd), `Hệ Thống` (6, 0ms cd), `Chiêu Mộ` (7, 10s cd), `Góp Ý` (8, 5s cd).
   - Provided `CHANNEL_I18N` supporting 8 channels across all 9 canonical languages (`vi`, `en`, `zh`, `ja`, `ko`, `th`, `de`, `ru`, `es`), ensuring tab labels remain <= 2 words.
   - Maintained a 100-message FIFO ring buffer per channel (`MAX_RING_BUFFER = 100`) via `addChatMessage(msg)`.
   - Built auto-scroll locking (`updateScrollLockState`) ensuring user scrolling is preserved when reading chat history.
   - Built anti-spam cooldown display disabling send button and showing `Chờ {sec}s` badge.
   - Implemented `parseItemTags`, `formatItemTag`, and `renderMessageHtml` converting `[item:{uuid}:{sig}:{name}:{rarity}]` into interactive `.chat-item-link` buttons with rarity colors and sanitizing raw HTML.
   - Integrated `#modal-item-link-tooltip` opening via `openItemTooltip` with Wuxia styling, rarity border, quality, ilvl, crafter, elemental affixes, and the green `[✓ HMAC Xác Thực]` badge.
   - Added SSR / Node.js safety guards (`typeof window !== 'undefined'`, `typeof document !== 'undefined'`).

3. **DOM Mounting (`client/webapp/index.html`)**:
   - Mounted `#chat-dock` (minimized bar `#chat-minimized-bar`, ticker channel `#chat-ticker-channel`, ticker text `#chat-ticker-text`, expanded panel `#chat-expanded-panel`, channel tabs `data-channel-id="1"` to `"8"`, collapse button `#chat-btn-collapse`, messages container `#chat-messages-container`, input `#chat-input`, send button `#chat-send-btn`, cooldown badge `#chat-cooldown-badge`).
   - Mounted 2.5D Cổ Võ `#modal-item-link-tooltip` (`#item-tooltip-icon`, `#item-tooltip-name`, `#item-tooltip-sub`, `#item-tooltip-affixes`, `#item-tooltip-crafter`, `#item-tooltip-hmac-badge` with `✓ HMAC Xác Thực`, `#btn-close-item-tooltip`).
   - `index.html` total length is 249 lines (well below the 400 lines Hard Cap).

4. **Event Wiring (`client/webapp/js/main.js`)**:
   - Imported `initChatUI` from `./ui/chat_ui.js` and called during initialization.
   - Wired `Enter` key: when not typing in an input, pressing `Enter` expands the chat dock and focuses `#chat-input`. Inside `#chat-input`, pressing `Enter` dispatches `sendCurrentChatMessage()`.
   - Wired `Escape` key: dismisses `#modal-item-link-tooltip` or collapses `#chat-expanded-panel` before checking general modal dismissal.
   - Preserved all existing controls (WASD, skills, potion, weapon swap, proximity interaction `F`).
   - `main.js` total length is 262 lines (<= 350 lines Soft Cap).

5. **Unit Testing (`tests/unit/test_webapp_chat_ui.py`)**:
   - Authored 13 automated unit tests validating DOM elements, channel keys, SLA cooldowns, 100-msg ring buffer FIFO eviction, rich item tag parsing, formatting, HTML sanitization, 9-language channel translations, microcopy brevity, and key wiring.
   - Execution command `python -m unittest tests/unit/test_webapp_chat_ui.py` passed 13/13 tests in 0.68s.

6. **Hygiene Verification (`tools/lint/check_code_and_doc_hygiene.py`)**:
   - Command `python tools/lint/check_code_and_doc_hygiene.py --strict` returned exit code 0 with 0 Hard Cap violations and 0 errors.

---

## 2. LOGIC CHAIN

```mermaid
flowchart TD
    A["proto/chat.proto & ChatMessage / ItemLinkSnapshot"] --> B["ChatManager.ts (TypeScript Engine)"]
    B --> C["chat_ui.js (Native ES Module WebApp UI)"]
    C --> D["8 Channel Tabs (World, Zone, Guild, Party, Whisper, System, Recruit, Feedback)"]
    C --> E["100-Message FIFO Ring Buffer per Channel"]
    C --> F["Rich Item Link Tags: [item:uuid:sig:name:rarity]"]
    F --> G["2.5D Modal Tooltip with [✓ HMAC Xác Thực] Badge"]
    H["index.html"] --> C
    I["main.js"] --> J["Enter Key -> Focus Chat / Send"]
    I --> K["Escape Key -> Dismiss Tooltip / Collapse Chat"]
    C --> L["test_webapp_chat_ui.py (13 Tests PASS)"]
```

1. Step 1: `proto/chat.proto` defines `ItemLinkSnapshot` containing `item_level`, `created_at_ms`, and `affixes`. `ChatManager.ts` aligns with this schema, allowing TypeScript clients to handle full cryptographic item snapshots.
2. Step 2: In `chat_ui.js`, 8 channels are mapped with their exact cooldowns and styles. A ring buffer of max 100 messages ensures DOM and memory stability under high message frequency.
3. Step 3: By parsing `[item:uuid:sig:name:rarity]`, chat messages display interactive badges that pop open `#modal-item-link-tooltip`, showcasing the item's verified HMAC signature without querying the server when cached.
4. Step 4: Mounting `#chat-dock` and `#modal-item-link-tooltip` in `index.html` provides the DOM nodes natively, and `main.js` connects `Enter` and `Escape` shortcuts without disrupting player movement or combat hotkeys.
5. Step 5: Independent test suite `tests/unit/test_webapp_chat_ui.py` executes these paths and verifies 100% compliance.

---

## 3. CAVEATS

- No caveats. All changes are confined exclusively to assigned files and satisfy all line-length and architecture requirements.

---

## 4. CONCLUSION

Milestone M2 (Client Chat Engine & WebApp UI Integration) is fully completed and verified.
- `client/src/chat/ChatManager.ts` compiles cleanly with TypeScript (`tsc` exit code 0).
- `client/webapp/js/ui/chat_ui.js` is implemented as an ES module adhering strictly to Soft Cap <= 350 lines (349 lines).
- `client/webapp/index.html` and `client/webapp/js/main.js` mount and wire the multi-channel dock and 2.5D HMAC tooltip without any regression.
- `tests/unit/test_webapp_chat_ui.py` passes 13/13 unit tests.
- Zero hygiene hard cap violations across all files.

---

## 5. VERIFICATION METHOD

To independently verify the implementation:

1. **Verify TypeScript compilation**:
   ```powershell
   cd c:\Projects\FreeExile\client
   npm run build
   ```
   *Expected Result*: Exits 0 with `tsc` building `client/dist/chat/ChatManager.js`.

2. **Verify WebApp Chat UI Unit Tests**:
   ```powershell
   python -m unittest tests/unit/test_webapp_chat_ui.py
   ```
   *Expected Result*: Ran 13 tests in < 1.0s, OK.

3. **Verify Regression Test Suites**:
   ```powershell
   python -m unittest tests/unit/test_mobile_webapp_config.py
   python -m unittest tests/unit/test_webapp_localization_engine.py
   python -m unittest tests/unit/test_chat_service.py tests/unit/test_chat_and_moderation.py
   python -m unittest tests/e2e/test_chat_distributed_system_e2e.py
   ```
   *Expected Result*: 100% PASS across all suites.

4. **Verify Strict Code and Doc Hygiene**:
   ```powershell
   python tools/lint/check_code_and_doc_hygiene.py --strict
   ```
   *Expected Result*: Exit code 0, 0 Hard Cap violations.