# Create your views here.
import os
from rest_framework.decorators import action
from rest_framework.response import Response
from rest_framework import status, viewsets, serializers
from rest_framework.permissions import IsAuthenticated
from crud_book.models import CrudBookModel, ReadingProgress
from crud_book.serializers import (
    CrudBookModelSerializer, 
    CrudBookModelCreateUpdateSerializer,
    ReadingProgressSerializer
)
from dvadmin.utils.viewset import CustomModelViewSet


class CrudBookModelViewSet(CustomModelViewSet):
    """
    list:查询
    create:新增
    update:修改
    retrieve:单例
    destroy:删除
    """
    queryset = CrudBookModel.objects.all()
    serializer_class = CrudBookModelSerializer
    create_serializer_class = CrudBookModelCreateUpdateSerializer
    update_serializer_class = CrudBookModelCreateUpdateSerializer

    @action(detail=True, methods=['get'])
    def file(self, request, pk=None):
        """
        获取图书文件信息或直接下载文件
        """
        try:
            # 先检查图书是否存在
            try:
                book = self.get_object()
            except Exception as e:
                return Response(
                    {'code': 404, 'msg': f'图书不存在: {str(e)}'},
                    status=status.HTTP_404_NOT_FOUND
                )
            
            # 检查图书是否有文件
            if not book.file:
                return Response(
                    {'code': 404, 'msg': '该图书没有上传文件'},
                    status=status.HTTP_404_NOT_FOUND
                )
            
            # 检查文件是否实际存在于文件系统
            if not os.path.exists(book.file.path):
                return Response(
                    {'code': 404, 'msg': '文件在服务器上不存在'},
                    status=status.HTTP_404_NOT_FOUND
                )
            
            # 返回文件URL信息作为标准格式
            file_url = request.build_absolute_uri(book.file.url)
            return Response({
                'code': 2000,
                'data': {
                    'file_url': file_url,
                    'file_type': book.file_type or 'epub',
                    'filename': os.path.basename(book.file.name)
                },
                'msg': '成功'
            }, status=status.HTTP_200_OK)
                
        except Exception as e:
            return Response(
                {'code': 500, 'msg': f'服务器错误: {str(e)}'},
                status=status.HTTP_500_INTERNAL_SERVER_ERROR
            )


class ReadingProgressViewSet(viewsets.ModelViewSet):
    """
    阅读进度管理
    """
    queryset = ReadingProgress.objects.all()
    serializer_class = ReadingProgressSerializer
    permission_classes = [IsAuthenticated]

    def get_queryset(self):
        """只返回当前用户的阅读进度"""
        return ReadingProgress.objects.filter(user=self.request.user)

    def create(self, request, *args, **kwargs):
        """创建或更新阅读进度"""
        # 检查用户是否已认证
        if not request.user.is_authenticated:
            return Response(
                {'code': 401, 'msg': '用户未登录，无法保存阅读进度'},
                status=status.HTTP_401_UNAUTHORIZED
            )
            
        # 获取序列化器
        serializer = self.get_serializer(data=request.data)
        
        try:
            # 验证数据
            serializer.is_valid(raise_exception=True)
            
            # 尝试查找现有记录
            try:
                book_id = request.data.get('book_id')
                book = CrudBookModel.objects.get(id=book_id)
                
                # 使用update_or_create而不是普通的save，避免重复记录
                progress, created = ReadingProgress.objects.get_or_create(
                    user=request.user,
                    book=book
                )
                
                # 更新字段
                progress.location = request.data.get('location', '')
                progress.progress = request.data.get('progress', 0)
                progress.creator = request.user  # 确保设置creator
                progress.save()
                
                # 返回更新后的序列化数据，包装成前端期望的格式
                serializer = self.get_serializer(progress)
                return Response(
                    {'code': 2000, 'data': serializer.data, 'msg': '成功'},
                    status=status.HTTP_200_OK
                )
                
            except CrudBookModel.DoesNotExist:
                return Response(
                    {'code': 404, 'msg': f'ID为{book_id}的图书不存在'},
                    status=status.HTTP_404_NOT_FOUND
                )
                
        except serializers.ValidationError as e:
            # 返回序列化验证错误
            return Response(
                {'code': 400, 'msg': str(e.detail)},
                status=status.HTTP_400_BAD_REQUEST
            )
        except Exception as e:
            # 记录错误
            import logging
            logger = logging.getLogger(__name__)
            logger.error(f'保存阅读进度失败: {str(e)}')
            
            return Response(
                {'code': 500, 'msg': f'保存阅读进度失败: {str(e)}'},
                status=status.HTTP_500_INTERNAL_SERVER_ERROR
            )

    @action(detail=False, methods=['get'])
    def by_book(self, request):
        """根据图书ID获取阅读进度"""
        book_id = request.query_params.get('book_id')
        if not book_id:
            return Response(
                {'code': 400, 'msg': '缺少book_id参数'},
                status=status.HTTP_400_BAD_REQUEST
            )

        try:
            progress = ReadingProgress.objects.get(
                user=request.user,
                book_id=book_id
            )
            serializer = self.get_serializer(progress)
            return Response(
                {'code': 2000, 'data': serializer.data, 'msg': '成功'},
                status=status.HTTP_200_OK
            )
        except ReadingProgress.DoesNotExist:
            return Response(
                {'code': 2000, 'data': {'location': '', 'progress': 0}, 'msg': '未找到阅读进度记录'},
                status=status.HTTP_200_OK
            )