from rest_framework import viewsets, filters, status
from rest_framework.decorators import action
from rest_framework.response import Response
from django_filters.rest_framework import DjangoFilterBackend
from .models import TrainingRecord, TrainingScoreDetail
from .serializers import (
    TrainingRecordListSerializer, TrainingRecordDetailSerializer,
    TrainingRecordCreateSerializer, TrainingScoreDetailSerializer
)


class TrainingRecordViewSet(viewsets.ModelViewSet):
    """训练记录管理
    
    list: 获取训练记录列表（支持过滤、搜索、排序）
    create: 开始训练（创建记录）
    retrieve: 获取训练详情
    update: 更新训练记录
    destroy: 删除训练记录
    """
    queryset = TrainingRecord.objects.all()
    filter_backends = [DjangoFilterBackend, filters.SearchFilter, filters.OrderingFilter]
    filterset_fields = [
        'user', 'case', 'training_mode', 'case_type',
        'teacher', 'evaluation_level', 'status'
    ]
    search_fields = ['feedback']
    ordering_fields = ['start_time', 'end_time', 'total_score', 'created_at']

    def get_serializer_class(self):
        if self.action == 'list':
            return TrainingRecordListSerializer
        elif self.action == 'create':
            return TrainingRecordCreateSerializer
        return TrainingRecordDetailSerializer

    def get_queryset(self):
        """普通用户只能看到自己的记录，老师可以看到学生的"""
        queryset = super().get_queryset()
        user = self.request.user
        
        # 超级管理员可以看所有
        if user.is_superuser:
            return queryset
            
        # 老师可以看到自己学生的记录
        return queryset.filter(user=user) | queryset.filter(teacher=user)

    @action(detail=True, methods=['get'])
    def score_details(self, request, pk=None):
        """获取训练评分明细"""
        record = self.get_object()
        details = record.score_details.all()
        serializer = TrainingScoreDetailSerializer(details, many=True)
        return Response(serializer.data)

    @action(detail=True, methods=['post'])
    def complete(self, request, pk=None):
        """完成训练"""
        record = self.get_object()
        record.status = 'completed'
        record.end_time = timezone.now()
        
        # 计算训练时长
        if record.start_time:
            duration = (record.end_time - record.start_time).total_seconds()
            record.duration_seconds = int(duration)
        
        record.save()
        
        # 更新用户统计
        user = record.user
        user.total_training_count += 1
        user.total_case_count += 1
        user.save()
        
        return Response({'message': '训练已完成', 'duration_seconds': record.duration_seconds})

    @action(detail=True, methods=['post'])
    def abort(self, request, pk=None):
        """中断训练"""
        record = self.get_object()
        record.status = 'aborted'
        record.end_time = timezone.now()
        record.interruption_count += 1
        record.save()
        return Response({'message': '训练已中断'})

    @action(detail=True, methods=['post'])
    def add_score(self, request, pk=None):
        """添加评分"""
        record = self.get_object()
        serializer = TrainingScoreDetailSerializer(data=request.data)
        serializer.is_valid(raise_exception=True)
        serializer.save(record=record)
        return Response(serializer.data, status=status.HTTP_201_CREATED)


class TrainingScoreDetailViewSet(viewsets.ModelViewSet):
    """评分明细管理"""
    queryset = TrainingScoreDetail.objects.all()
    serializer_class = TrainingScoreDetailSerializer
    filter_backends = [DjangoFilterBackend]
    filterset_fields = ['record', 'rule', 'dimension']