feat: Phase 2 - 服务层实现 + Bug修复

app/services/session_service.py

@@ -0,0 +1,168 @@
+"""
+会话服务
+处理会话相关的业务逻辑
+"""
+from typing import Optional, List
+from datetime import datetime
+from app.models import db, Session, Agent
+from app.services.scheduler import AgentScheduler
+
+
+class SessionService:
+    """会话服务"""
+    
+    def __init__(self, scheduler_strategy: str = 'weighted_round_robin'):
+        self.scheduler = AgentScheduler(scheduler_strategy)
+    
+    def create_session(
+        self,
+        user_id: str,
+        title: str = None,
+        agent_id: str = None,
+        channel_type: str = 'web',
+        context: dict = None
+    ) -> Session:
+        """创建新会话"""
+        # 如果没有指定 Agent，调度一个
+        if not agent_id:
+            from app.models import Agent
+            agents = Agent.query.all()
+            selected_agent = self.scheduler.select_agent(agents, context)
+            agent_id = selected_agent.id if selected_agent else None
+        
+        # 创建会话
+        session = Session(
+            user_id=user_id,
+            primary_agent_id=agent_id,
+            title=title or f"Session {datetime.utcnow().strftime('%Y-%m-%d %H:%M')}",
+            channel_type=channel_type,
+            status='active'
+        )
+        
+        db.session.add(session)
+        
+        # 更新 Agent 会话数
+        if agent_id:
+            agent = Agent.query.get(agent_id)
+            if agent:
+                agent.current_sessions += 1
+        
+        db.session.commit()
+        
+        return session
+    
+    def close_session(self, session_id: str, user_id: str = None) -> Optional[Session]:
+        """关闭会话"""
+        session = Session.query.get(session_id)
+        if not session:
+            return None
+        
+        # 验证权限
+        if user_id and session.user_id != user_id:
+            return None
+        
+        session.status = 'closed'
+        session.updated_at = datetime.utcnow()
+        
+        # 更新 Agent 会话数
+        if session.primary_agent_id:
+            agent = Agent.query.get(session.primary_agent_id)
+            if agent and agent.current_sessions > 0:
+                agent.current_sessions -= 1
+        
+        db.session.commit()
+        
+        return session
+    
+    def get_user_sessions(self, user_id: str, status: str = None) -> List[Session]:
+        """获取用户会话列表"""
+        query = Session.query.filter_by(user_id=user_id)
+        
+        if status:
+            query = query.filter_by(status=status)
+        
+        return query.order_by(Session.created_at.desc()).all()
+    
+    def get_session(self, session_id: str, user_id: str = None) -> Optional[Session]:
+        """获取会话详情"""
+        session = Session.query.get(session_id)
+        
+        if not session:
+            return None
+        
+        if user_id and session.user_id != user_id:
+            return None
+        
+        return session
+    
+    def update_session_activity(self, session_id: str) -> bool:
+        """更新会话活跃时间"""
+        session = Session.query.get(session_id)
+        if not session:
+            return False
+        
+        session.last_active_at = datetime.utcnow()
+        session.message_count += 1
+        db.session.commit()
+        
+        return True
+    
+    def assign_agent(self, session_id: str, agent_id: str) -> Optional[Session]:
+        """分配 Agent 到会话"""
+        session = Session.query.get(session_id)
+        if not session:
+            return None
+        
+        # 验证 Agent 是否在线
+        agent = Agent.query.get(agent_id)
+        if not agent or agent.status != 'online':
+            return None
+        
+        # 更新会话
+        old_agent_id = session.primary_agent_id
+        session.primary_agent_id = agent_id
+        
+        # 更新新旧 Agent 的会话数
+        if old_agent_id:
+            old_agent = Agent.query.get(old_agent_id)
+            if old_agent and old_agent.current_sessions > 0:
+                old_agent.current_sessions -= 1
+        
+        agent.current_sessions += 1
+        
+        db.session.commit()
+        
+        return session
+    
+    def add_participant(self, session_id: str, agent_id: str) -> Optional[Session]:
+        """添加参与 Agent"""
+        session = Session.query.get(session_id)
+        if not session:
+            return None
+        
+        # 获取当前参与列表
+        participants = session.participating_agent_ids or []
+        
+        if agent_id not in participants:
+            participants.append(agent_id)
+            session.participating_agent_ids = participants
+        
+        db.session.commit()
+        
+        return session
+    
+    def remove_participant(self, session_id: str, agent_id: str) -> Optional[Session]:
+        """移除参与 Agent"""
+        session = Session.query.get(session_id)
+        if not session:
+            return None
+        
+        participants = session.participating_agent_ids or []
+        
+        if agent_id in participants:
+            participants.remove(agent_id)
+            session.participating_agent_ids = participants
+        
+        db.session.commit()
+        
+        return session