Add multi-device support for Video Learning Agent

- Add device-session bidirectional mapping (_device_sessions)
- Integrate DeviceManager lock mechanism (acquire/release)
- Add device-level API endpoints:
  - GET /devices/{device_id}/sessions - List sessions on device
  - POST /devices/{device_id}/stop-all - Stop all sessions on device
  - GET /devices/sessions - Overview of all devices
- Update session cleanup to maintain mapping consistency
- Prevent concurrent sessions on same device

Co-Authored-By: Claude <noreply@anthropic.com>

dashboard/api/video_learning.py

@@ -64,7 +64,11 @@ class VideoInfo(BaseModel):
 
 
 # Global session storage (in production, use database)
+# 会话存储：session_id -> VideoLearningAgent
 _active_sessions: Dict[str, VideoLearningAgent] = {}
+# 设备-会话映射：device_id -> {session_ids}
+# 支持多设备同时运行，每个设备可以有多个会话（但同一时间只能有一个活跃的）
+_device_sessions: Dict[str, set[str]] = {}
 
 
 @router.post("/sessions", response_model=Dict[str, str])
@@ -81,67 +85,86 @@ async def create_session(
     if not device.is_connected:
         raise HTTPException(status_code=400, detail="Device not connected")
 
-    if device.status == "busy":
-        raise HTTPException(status_code=409, detail="Device is busy")
+    # 使用设备锁机制确保同一设备不会同时运行多个会话
+    if not device_manager.acquire_device(request.device_id):
+        raise HTTPException(status_code=409, detail="Device is busy - another session is running on this device")
 
-    # Create model config from environment
-    model_config = ModelConfig(
-        base_url=config.MODEL_BASE_URL,
-        model_name=config.MODEL_NAME,
-        api_key=config.MODEL_API_KEY,
-        max_tokens=config.MAX_TOKENS,
-        temperature=config.TEMPERATURE,
-        top_p=config.TOP_P,
-        frequency_penalty=config.FREQUENCY_PENALTY,
-        lang="cn",
-    )
+    try:
+        # Create model config from environment
+        model_config = ModelConfig(
+            base_url=config.MODEL_BASE_URL,
+            model_name=config.MODEL_NAME,
+            api_key=config.MODEL_API_KEY,
+            max_tokens=config.MAX_TOKENS,
+            temperature=config.TEMPERATURE,
+            top_p=config.TOP_P,
+            frequency_penalty=config.FREQUENCY_PENALTY,
+            lang="cn",
+        )
 
-    # Create video learning agent
-    agent = VideoLearningAgent(
-        model_config=model_config,
-        platform=request.platform,
-        output_dir=config.VIDEO_LEARNING_OUTPUT_DIR,
-        enable_analysis=request.enable_analysis,
-    )
+        # Create video learning agent
+        agent = VideoLearningAgent(
+            model_config=model_config,
+            platform=request.platform,
+            output_dir=config.VIDEO_LEARNING_OUTPUT_DIR,
+            enable_analysis=request.enable_analysis,
+        )
 
-    # Setup callbacks for real-time updates
-    session_id = None
+        # Setup callbacks for real-time updates
+        session_id = None
 
-    def on_video_watched(record):
-        """Callback when a video is watched."""
-        # Broadcast via WebSocket
-        if session_id:
-            # This would be integrated with WebSocket manager
-            pass
+        def on_video_watched(record):
+            """Callback when a video is watched."""
+            if session_id:
+                pass  # WebSocket broadcast would go here
 
-    def on_progress_update(current, total):
-        """Callback for progress updates."""
-        if session_id:
-            # Broadcast progress
-            pass
+        def on_progress_update(current, total):
+            """Callback for progress updates."""
+            if session_id:
+                pass  # Progress broadcast would go here
 
-    def on_session_complete(session):
-        """Callback when session completes."""
-        if session_id and session_id in _active_sessions:
-            del _active_sessions[session_id]
+        def on_session_complete(session):
+            """Callback when session completes - release device lock and clean up."""
+            if session_id:
+                # 从设备-会话映射中移除
+                if request.device_id in _device_sessions:
+                    _device_sessions[request.device_id].discard(session_id)
+                    if not _device_sessions[request.device_id]:
+                        del _device_sessions[request.device_id]
 
-    agent.on_video_watched = on_video_watched
-    agent.on_progress_update = on_progress_update
-    agent.on_session_complete = on_session_complete
+                # 从活跃会话中移除（但保留历史记录可查询）
+                if session_id in _active_sessions:
+                    # 标记为完成但不删除，允许用户查看结果
+                    pass
 
-    # Start session
-    session_id = agent.start_session(
-        device_id=request.device_id,
-        target_count=request.target_count,
-        category=request.category,
-        watch_duration=request.watch_duration,
-        max_steps=500,
-    )
+                # 释放设备锁
+                device_manager.release_device(request.device_id)
 
-    # Store session
-    _active_sessions[session_id] = agent
+        agent.on_video_watched = on_video_watched
+        agent.on_progress_update = on_progress_update
+        agent.on_session_complete = on_session_complete
 
-    return {"session_id": session_id, "status": "created"}
+        # Start session
+        session_id = agent.start_session(
+            device_id=request.device_id,
+            target_count=request.target_count,
+            category=request.category,
+            watch_duration=request.watch_duration,
+            max_steps=500,
+        )
+
+        # Store session in both mappings
+        _active_sessions[session_id] = agent
+        if request.device_id not in _device_sessions:
+            _device_sessions[request.device_id] = set()
+        _device_sessions[request.device_id].add(session_id)
+
+        return {"session_id": session_id, "status": "created"}
+
+    except Exception as e:
+        # 创建失败时释放设备锁
+        device_manager.release_device(request.device_id)
+        raise HTTPException(status_code=500, detail=f"Failed to create session: {str(e)}")
 
 
 @router.post("/sessions/{session_id}/start", response_model=Dict[str, str])
@@ -330,11 +353,26 @@ async def list_sessions() -> List[str]:
 
 @router.delete("/sessions/{session_id}", response_model=Dict[str, str])
 async def delete_session(session_id: str) -> Dict[str, str]:
-    """Delete a session."""
+    """Delete a session and clean up device mapping."""
     if session_id not in _active_sessions:
         raise HTTPException(status_code=404, detail="Session not found")
 
+    # 获取设备ID以便清理映射
+    agent = _active_sessions[session_id]
+    device_id = None
+    if agent.current_session:
+        # 从 session 中获取 device_id
+        device_id = agent._device_id
+
+    # 删除会话
     del _active_sessions[session_id]
+
+    # 清理设备-会话映射
+    if device_id and device_id in _device_sessions:
+        _device_sessions[device_id].discard(session_id)
+        if not _device_sessions[device_id]:
+            del _device_sessions[device_id]
+
     return {"session_id": session_id, "status": "deleted"}
 
 
@@ -361,3 +399,78 @@ async def analyze_session(session_id: str) -> Dict[str, Any]:
         "analyzed_count": analyzed_count,
         "status": "analysis_triggered"
     }
+
+
+# ==================== 设备级别的 API ====================
+
+@router.get("/devices/{device_id}/sessions")
+async def get_device_sessions(device_id: str) -> List[Dict[str, Any]]:
+    """获取指定设备上的所有会话"""
+    if device_id not in _device_sessions:
+        return []
+
+    session_ids = _device_sessions[device_id]
+    result = []
+    for sid in session_ids:
+        if sid in _active_sessions:
+            agent = _active_sessions[sid]
+            progress = agent.get_session_progress()
+            result.append({
+                "session_id": sid,
+                "platform": progress.get("platform", ""),
+                "target_count": progress.get("target_count", 0),
+                "watched_count": progress.get("watched_count", 0),
+                "progress_percent": progress.get("progress_percent", 0),
+                "is_active": progress.get("is_active", False),
+                "is_paused": progress.get("is_paused", False),
+            })
+    return result
+
+
+@router.post("/devices/{device_id}/stop-all", response_model=Dict[str, Any])
+async def stop_all_device_sessions(device_id: str) -> Dict[str, Any]:
+    """停止指定设备上的所有活跃会话"""
+    if device_id not in _device_sessions:
+        return {"device_id": device_id, "stopped": 0, "message": "No sessions on this device"}
+
+    count = 0
+    session_ids = list(_device_sessions[device_id])
+    for session_id in session_ids:
+        if session_id in _active_sessions:
+            agent = _active_sessions[session_id]
+            # 只停止活跃的会话
+            if agent.current_session and agent.current_session.is_active:
+                agent.stop_session()
+                count += 1
+
+    return {
+        "device_id": device_id,
+        "stopped": count,
+        "message": f"Stopped {count} active session(s) on device {device_id}"
+    }
+
+
+@router.get("/devices/sessions", response_model=Dict[str, Any])
+async def get_all_device_sessions() -> Dict[str, Any]:
+    """获取所有设备上的会话概览"""
+    result = {
+        "devices": {},
+        "total_devices": len(_device_sessions),
+        "total_sessions": len(_active_sessions)
+    }
+
+    for device_id, session_ids in _device_sessions.items():
+        active_count = 0
+        for sid in session_ids:
+            if sid in _active_sessions:
+                agent = _active_sessions[sid]
+                if agent.current_session and agent.current_session.is_active:
+                    active_count += 1
+
+        result["devices"][device_id] = {
+            "total_sessions": len(session_ids),
+            "active_sessions": active_count,
+            "session_ids": list(session_ids)
+        }
+
+    return result