from rest_framework import serializers, status, views
from rest_framework.response import Response
from django.contrib.auth import authenticate, get_user_model

User = get_user_model()


class LoginSerializer(serializers.Serializer):
    username = serializers.CharField()
    password = serializers.CharField()
    login_mode = serializers.ChoiceField(
        choices=['human_only', 'agent_only', 'both'],
        default='human_only'
    )
    selected_agent_id = serializers.CharField(required=False, allow_blank=True)


class LoginView(views.APIView):
    def post(self, request):
        serializer = LoginSerializer(data=request.data)
        if not serializer.is_valid():
            return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
        
        username = serializer.validated_data['username']
        password = serializer.validated_data['password']
        login_mode = serializer.validated_data.get('login_mode', 'human_only')
        selected_agent_id = serializer.validated_data.get('selected_agent_id')
        
        user = authenticate(username=username, password=password)
        if not user:
            return Response(
                {'detail': '用户名或密码错误'},
                status=status.HTTP_401_UNAUTHORIZED
            )
        
        # 简单 Token（生产环境应该用 JWT）
        import uuid
        token = uuid.uuid4().hex
        
        # 构建会话信息
        sessions = []
        
        if login_mode in ['human_only', 'both']:
            # 人类身份
            sessions.append({
                'session_type': 'human',
                'nickname': user.username,
                'emoji': '👤',
                'user_id': user.id
            })
        
        if login_mode in ['agent_only', 'both']:
            # 龙虾身份
            if selected_agent_id:
                agent = user.get_linked_agent(selected_agent_id)
                if agent:
                    sessions.append({
                        'session_type': 'agent',
                        'agent_id': agent['agent_id'],
                        'agent_name': agent['agent_name'],
                        'nickname': agent['agent_name'],
                        'emoji': agent.get('agent_emoji', '🤖'),
                        'instance_id': agent.get('instance_id')
                    })
                else:
                    return Response(
                        {'error': f'未找到绑定的龙虾：{selected_agent_id}'},
                        status=status.HTTP_400_BAD_REQUEST
                    )
        
        return Response({
            'token': token,
            'user': {
                'id': user.id,
                'username': user.username,
                'email': user.email,
                'linked_agents': user.linked_agents
            },
            'sessions': sessions,
            'login_mode': login_mode
        })


class RegisterSerializer(serializers.Serializer):
    username = serializers.CharField()
    email = serializers.EmailField()
    password = serializers.CharField()


class RegisterView(views.APIView):
    def post(self, request):
        serializer = RegisterSerializer(data=request.data)
        if not serializer.is_valid():
            return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
        
        try:
            user = User.objects.create_user(
                username=serializer.validated_data['username'],
                email=serializer.validated_data['email'],
                password=serializer.validated_data['password']
            )
            
            import uuid
            token = uuid.uuid4().hex
            
            return Response({
                'token': token,
                'user': {
                    'id': user.id,
                    'username': user.username,
                    'email': user.email
                }
            }, status=status.HTTP_201_CREATED)
        except Exception as e:
            return Response(
                {'detail': str(e)},
                status=status.HTTP_400_BAD_REQUEST
            )


class LinkedAgentsView(views.APIView):
    """
    用户绑定的龙虾管理
    
    GET /api/v1/user/linked-agents/?username=xxx - 获取龙虾列表
    POST /api/v1/user/linked-agents/ - 添加龙虾
    DELETE /api/v1/user/linked-agents/{agent_id}/?username=xxx - 移除龙虾
    """
    def get(self, request):
        username = request.query_params.get('username')
        if not username:
            return Response({'error': '缺少 username'}, status=status.HTTP_400_BAD_REQUEST)
        
        try:
            user = User.objects.get(username=username)
            return Response({
                'linked_agents': user.linked_agents,
                'count': len(user.linked_agents)
            })
        except User.DoesNotExist:
            return Response({'error': '用户不存在'}, status=status.HTTP_404_NOT_FOUND)
    
    def post(self, request):
        username = request.data.get('username')
        agent_id = request.data.get('agent_id')
        agent_name = request.data.get('agent_name')
        agent_emoji = request.data.get('agent_emoji', '🤖')
        instance_id = request.data.get('instance_id')
        
        if not all([username, agent_id, agent_name]):
            return Response({'error': '缺少必要参数'}, status=status.HTTP_400_BAD_REQUEST)
        
        try:
            user = User.objects.get(username=username)
            user.add_linked_agent(agent_id, agent_name, agent_emoji, instance_id)
            return Response({
                'status': 'success',
                'linked_agents': user.linked_agents
            })
        except User.DoesNotExist:
            return Response({'error': '用户不存在'}, status=status.HTTP_404_NOT_FOUND)
    
    def delete(self, request, agent_id):
        username = request.query_params.get('username')
        if not username:
            return Response({'error': '缺少 username'}, status=status.HTTP_400_BAD_REQUEST)
        
        try:
            user = User.objects.get(username=username)
            user.remove_linked_agent(agent_id)
            return Response({
                'status': 'success',
                'linked_agents': user.linked_agents
            })
        except User.DoesNotExist:
            return Response({'error': '用户不存在'}, status=status.HTTP_404_NOT_FOUND)


class ScanLocalAgentsView(views.APIView):
    """
    扫描本机龙虾列表
    
    GET /api/v1/user/scan-local-agents/?instance_id=xxx - 扫描指定实例
    GET /api/v1/user/scan-local-agents/ - 扫描所有实例
    """
    def get(self, request):
        instance_id = request.query_params.get('instance_id')
        
        if not instance_id:
            # 返回所有已注册实例的 Agent
            from instances.models import Instance
            instances = Instance.objects.filter(is_active=True)
            agents = []
            for inst in instances:
                for agent_id in inst.agent_ids:
                    agents.append({
                        'agent_id': agent_id,
                        'instance_id': inst.instance_id,
                        'instance_name': inst.instance_name
                    })
        else:
            # 返回指定实例的 Agent
            from instances.models import Instance
            try:
                instance = Instance.objects.get(instance_id=instance_id, is_active=True)
                agents = [{
                    'agent_id': agent_id,
                    'instance_id': instance.instance_id,
                    'instance_name': instance.instance_name
                } for agent_id in instance.agent_ids]
            except Instance.DoesNotExist:
                return Response({'error': '实例不存在'}, status=status.HTTP_404_NOT_FOUND)
        
        return Response({
            'agents': agents,
            'count': len(agents)
        })