import logging
import json
import traceback
import uuid
from datetime import datetime
from django.db.models import Q, Max, Count
from django.http import HttpResponse, StreamingHttpResponse
from rest_framework import viewsets, status
from rest_framework.permissions import IsAuthenticated
from rest_framework.response import Response
from rest_framework.decorators import action
from apps.user.models import User
from apps.chat.models import ChatHistory
from apps.chat.serializers import ChatHistorySerializer
from apps.user.authentication import CustomTokenAuthentication
from apps.common.services.chat_service import ChatService
from apps.chat.services.chat_api import (
    ExternalAPIError, stream_chat_answer, get_chat_answer,
    generate_conversation_title_from_deepseek
)
from apps.daren_detail.models import CreatorProfile
from apps.daren_detail.serializers import CreatorProfileSerializer, CreatorProfileListSerializer

logger = logging.getLogger(__name__)

class ChatHistoryViewSet(viewsets.ModelViewSet):
    permission_classes = [IsAuthenticated]
    authentication_classes = [CustomTokenAuthentication]
    serializer_class = ChatHistorySerializer
    queryset = ChatHistory.objects.all()
    
    # 固定知识库ID
    DEFAULT_KNOWLEDGE_BASE_ID = "b680a4fa-37be-11f0-a7cb-0242ac120002"

    def get_queryset(self):
        """只过滤用户自己的未删除的聊天记录"""
        user = self.request.user
        return ChatHistory.objects.filter(
            user=user,
            is_deleted=False
        )
    
    def list(self, request):
        """获取对话列表概览"""
        try:
            page = int(request.query_params.get('page', 1))
            page_size = int(request.query_params.get('page_size', 10))

            latest_chats = self.get_queryset().values(
                'conversation_id'
            ).annotate(
                latest_id=Max('id'),
                message_count=Count('id'),
                last_message=Max('created_at')
            ).order_by('-last_message')

            total = latest_chats.count()
            start = (page - 1) * page_size
            end = start + page_size
            chats = latest_chats[start:end]

            results = []
            for chat in chats:
                latest_record = ChatHistory.objects.get(id=chat['latest_id'])
                
                results.append({
                    'conversation_id': chat['conversation_id'],
                    'message_count': chat['message_count'],
                    'last_message': latest_record.content,
                    'last_time': chat['last_message'].strftime('%Y-%m-%d %H:%M:%S'),
                })

            return Response({
                'code': 200,
                'message': '获取成功',
                'data': {
                    'total': total,
                    'page': page,
                    'page_size': page_size,
                    'results': results
                }
            })

        except Exception as e:
            logger.error(f"获取聊天记录失败: {str(e)}")
            import traceback
            logger.error(traceback.format_exc())
            return Response({
                'code': 500,
                'message': f'获取聊天记录失败: {str(e)}',
                'data': None
            }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

    @action(detail=False, methods=['get'])
    def conversation_detail(self, request):
        """获取特定对话的详细信息"""
        try:
            conversation_id = request.query_params.get('conversation_id')
            if not conversation_id:
                return Response({
                    'code': 400,
                    'message': '缺少conversation_id参数',
                    'data': None
                }, status=status.HTTP_400_BAD_REQUEST)

            chat_service = ChatService()
            result = chat_service.get_conversation_detail(request.user, conversation_id)

            return Response({
                'code': 200,
                'message': '获取成功',
                'data': result
            })

        except ValueError as e:
            return Response({
                'code': 404,
                'message': str(e),
                'data': None
            }, status=status.HTTP_404_NOT_FOUND)
        except Exception as e:
            logger.error(f"获取对话详情失败: {str(e)}")
            import traceback
            logger.error(traceback.format_exc())
            return Response({
                'code': 500,
                'message': f'获取对话详情失败: {str(e)}',
                'data': None
            }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

    @action(detail=False, methods=['get'])
    def available_datasets(self, request):
        """获取默认知识库"""
        return Response({
            'code': 200,
            'message': '获取成功',
            'data': []
        })

    @action(detail=False, methods=['post'])
    def create_conversation(self, request):
        """创建会话 - 使用默认知识库ID"""
        try:
            # 创建一个新的会话ID
            conversation_id = str(uuid.uuid4())
            logger.info(f"创建新的会话ID: {conversation_id}")
            
            return Response({
                'code': 200,
                'message': '会话创建成功',
                'data': {
                    'conversation_id': conversation_id
                }
            })
            
        except Exception as e:
            logger.error(f"创建会话失败: {str(e)}")
            logger.error(traceback.format_exc())
            return Response({
                'code': 500,
                'message': f'创建会话失败: {str(e)}',
                'data': None
            }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)
            
    def create(self, request):
        """创建聊天记录 - 使用默认知识库"""
        try:
            # 验证请求数据
            if 'question' not in request.data:
                return Response({
                    'code': 400,
                    'message': '缺少必填字段: question',
                    'data': None
                }, status=status.HTTP_400_BAD_REQUEST)
            
            if 'conversation_id' not in request.data:
                return Response({
                    'code': 400,
                    'message': '缺少必填字段: conversation_id',
                    'data': None
                }, status=status.HTTP_400_BAD_REQUEST)
                
            conversation_id = request.data['conversation_id']
            question = request.data['question']
            title = request.data.get('title', 'New chat')
            
            # 准备metadata
            metadata = {}
            
            # 创建用户问题记录
            question_record = ChatHistory.objects.create(
                user=request.user,
                knowledge_base_id=self.DEFAULT_KNOWLEDGE_BASE_ID,
                conversation_id=conversation_id,
                title=title,
                role='user',
                content=question,
                metadata=metadata
            )
            
            # 设置外部API需要的ID列表
            external_id_list = []
            
            use_stream = request.data.get('stream', True)
            
            if use_stream:
                def stream_response():
                    answer_record = ChatHistory.objects.create(
                        user=question_record.user,
                        knowledge_base_id=self.DEFAULT_KNOWLEDGE_BASE_ID,
                        conversation_id=conversation_id,
                        title=title,
                        parent_id=str(question_record.id),
                        role='assistant',
                        content="",
                        metadata=metadata
                    )

                    yield f"data: {json.dumps({'code': 200, 'message': '开始流式传输', 'data': {'id': str(answer_record.id), 'conversation_id': conversation_id, 'content': '', 'is_end': False}})}\n\n"

                    full_content = ""
                    for data in stream_chat_answer(conversation_id, request.data['question'], external_id_list, metadata):
                        parsed_data = json.loads(data[5:-2])  # 移除"data: "和"\n\n"
                        if parsed_data['code'] == 200 and 'content' in parsed_data['data']:
                            content_part = parsed_data['data']['content']
                            full_content += content_part
                            response_data = {
                                'code': 200,
                                'message': 'partial',
                                'data': {
                                    'id': str(answer_record.id),
                                    'conversation_id': conversation_id,
                                    'title': title,
                                    'content': content_part,
                                    'is_end': parsed_data['data']['is_end']
                                }
                            }
                            yield f"data: {json.dumps(response_data)}\n\n"

                        if parsed_data['data']['is_end']:
                            answer_record.content = full_content.strip()
                            answer_record.save()

                            current_title = ChatHistory.objects.filter(
                                conversation_id=conversation_id
                            ).exclude(
                                title__in=["New chat", "新对话", ""]
                            ).values_list('title', flat=True).first()

                            if current_title:
                                title_updated = current_title
                            else:
                                try:
                                    generated_title = generate_conversation_title_from_deepseek(
                                        request.data['question'], full_content.strip()
                                    )
                                    if generated_title:
                                        ChatHistory.objects.filter(
                                            conversation_id=conversation_id
                                        ).update(title=generated_title)
                                        title_updated = generated_title
                                    else:
                                        title_updated = "新对话"
                                except Exception as e:
                                    logger.error(f"自动生成标题失败: {str(e)}")
                                    title_updated = "新对话"

                            final_response = {
                                'code': 200,
                                'message': '完成',
                                'data': {
                                    'id': str(answer_record.id),
                                    'conversation_id': conversation_id,
                                    'title': title_updated,
                                    'role': 'assistant',
                                    'content': full_content.strip(),
                                    'created_at': answer_record.created_at.strftime('%Y-%m-%d %H:%M:%S'),
                                    'is_end': True
                                }
                            }
                            yield f"data: {json.dumps(final_response)}\n\n"
                            break
                        elif parsed_data['code'] != 200:
                            yield data
                            break

                    if full_content:
                        try:
                            answer_record.content = full_content.strip()
                            answer_record.save()
                        except Exception as save_error:
                            logger.error(f"保存部分内容失败: {str(save_error)}")

                response = StreamingHttpResponse(
                    stream_response(),
                    content_type='text/event-stream',
                    status=status.HTTP_201_CREATED
                )
                response['Cache-Control'] = 'no-cache, no-store'
                response['Connection'] = 'keep-alive'
                return response
            else:
                logger.info("使用非流式输出模式")
                try:
                    answer = get_chat_answer(external_id_list, request.data['question'])
                except ExternalAPIError as e:
                    logger.error(f"获取回答失败: {str(e)}")
                    return Response({
                        'code': 500,
                        'message': f'获取回答失败: {str(e)}',
                        'data': None
                    }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

                if answer is None:
                    return Response({
                        'code': 500,
                        'message': '获取回答失败',
                        'data': None
                    }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

                answer_record = ChatHistory.objects.create(
                    user=request.user,
                    knowledge_base_id=self.DEFAULT_KNOWLEDGE_BASE_ID,
                    conversation_id=conversation_id,
                    title=title,
                    parent_id=str(question_record.id),
                    role='assistant',
                    content=answer,
                    metadata=metadata
                )

                existing_records = ChatHistory.objects.filter(conversation_id=conversation_id)
                should_generate_title = not existing_records.exclude(id=question_record.id).exists() and (not title or title == 'New chat')
                if should_generate_title:
                    try:
                        generated_title = generate_conversation_title_from_deepseek(
                            request.data['question'], answer
                        )
                        if generated_title:
                            ChatHistory.objects.filter(conversation_id=conversation_id).update(title=generated_title)
                            title = generated_title
                    except Exception as e:
                        logger.error(f"自动生成标题失败: {str(e)}")

                return Response({
                    'code': 200,
                    'message': '成功',
                    'data': {
                        'id': str(answer_record.id),
                        'conversation_id': conversation_id,
                        'title': title,
                        'role': 'assistant',
                        'content': answer,
                        'created_at': answer_record.created_at.strftime('%Y-%m-%d %H:%M:%S')
                    }
                }, status=status.HTTP_201_CREATED)

        except Exception as e:
            logger.error(f"创建聊天记录失败: {str(e)}")
            import traceback
            logger.error(traceback.format_exc())
            return Response({
                'code': 500,
                'message': f'创建聊天记录失败: {str(e)}',
                'data': None
            }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

    def _highlight_keyword(self, text, keyword):
        """高亮关键词"""
        if not keyword or not text:
            return text
        return text.replace(keyword, f'<em class="highlight">{keyword}</em>')

    def update(self, request, pk=None):
        """更新聊天记录"""
        try:
            record = self.get_queryset().filter(id=pk).first()
            if not record:
                return Response({
                    'code': 404,
                    'message': '记录不存在或无权限',
                    'data': None
                }, status=status.HTTP_404_NOT_FOUND)

            data = request.data
            updateable_fields = ['content', 'metadata']
            if 'content' in data:
                record.content = data['content']
            if 'metadata' in data:
                current_metadata = record.metadata or {}
                current_metadata.update(data['metadata'])
                record.metadata = current_metadata

            record.save()
            return Response({
                'code': 200,
                'message': '更新成功',
                'data': {
                    'id': str(record.id),
                    'conversation_id': record.conversation_id,
                    'role': record.role,
                    'content': record.content,
                    'metadata': record.metadata,
                    'updated_at': datetime.now().strftime('%Y-%m-%d %H:%M:%S')
                }
            })

        except Exception as e:
            logger.error(f"更新聊天记录失败: {str(e)}")
            import traceback
            logger.error(traceback.format_exc())
            return Response({
                'code': 500,
                'message': f'更新聊天记录失败: {str(e)}',
                'data': None
            }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

    def destroy(self, request, pk=None):
        """删除聊天记录（软删除）"""
        try:
            record = self.get_queryset().filter(id=pk).first()
            if not record:
                return Response({
                    'code': 404,
                    'message': '记录不存在或无权限',
                    'data': None
                }, status=status.HTTP_404_NOT_FOUND)

            record.soft_delete()
            return Response({
                'code': 200,
                'message': '删除成功',
                'data': None
            })

        except Exception as e:
            logger.error(f"删除聊天记录失败: {str(e)}")
            import traceback
            logger.error(traceback.format_exc())
            return Response({
                'code': 500,
                'message': f'删除聊天记录失败: {str(e)}',
                'data': None
            }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

    @action(detail=False, methods=['get'])
    def search(self, request):
        """搜索聊天记录"""
        try:
            keyword = request.query_params.get('keyword', '').strip()
            start_date = request.query_params.get('start_date')
            end_date = request.query_params.get('end_date')
            page = int(request.query_params.get('page', 1))
            page_size = int(request.query_params.get('page_size', 10))

            query = self.get_queryset()
            if keyword:
                query = query.filter(
                    Q(content__icontains=keyword)
                )
            if start_date:
                query = query.filter(created_at__gte=start_date)
            if end_date:
                query = query.filter(created_at__lte=end_date)

            total = query.count()
            start = (page - 1) * page_size
            end = start + page_size
            records = query.order_by('-created_at')[start:end]

            results = [
                {
                    'id': str(record.id),
                    'conversation_id': record.conversation_id,
                    'role': record.role,
                    'content': record.content,
                    'created_at': record.created_at.strftime('%Y-%m-%d %H:%M:%S'),
                    'metadata': record.metadata,
                    'highlights': {'content': self._highlight_keyword(record.content, keyword)} if keyword else {}
                }
                for record in records
            ]

            return Response({
                'code': 200,
                'message': '搜索成功',
                'data': {
                    'total': total,
                    'page': page,
                    'page_size': page_size,
                    'results': results
                }
            })

        except Exception as e:
            logger.error(f"搜索聊天记录失败: {str(e)}")
            import traceback
            logger.error(traceback.format_exc())
            return Response({
                'code': 500,
                'message': f'搜索失败: {str(e)}',
                'data': None
            }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

    @action(detail=False, methods=['delete'])
    def delete_conversation(self, request):
        """通过conversation_id删除一组会话"""
        try:
            conversation_id = request.query_params.get('conversation_id')
            if not conversation_id:
                return Response({
                    'code': 400,
                    'message': '缺少必要参数: conversation_id',
                    'data': None
                }, status=status.HTTP_400_BAD_REQUEST)

            records = self.get_queryset().filter(conversation_id=conversation_id)
            if not records.exists():
                return Response({
                    'code': 404,
                    'message': '未找到该会话或无权限访问',
                    'data': None
                }, status=status.HTTP_404_NOT_FOUND)

            records_count = records.count()
            for record in records:
                record.soft_delete()

            return Response({
                'code': 200,
                'message': '删除成功',
                'data': {
                    'conversation_id': conversation_id,
                    'deleted_count': records_count
                }
            })

        except Exception as e:
            logger.error(f"删除会话失败: {str(e)}")
            import traceback
            logger.error(traceback.format_exc())
            return Response({
                'code': 500,
                'message': f'删除会话失败: {str(e)}',
                'data': None
            }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)
        
    @action(detail=False, methods=['get'], url_path='generate-conversation-title')
    def generate_conversation_title(self, request):
        """更新会话标题"""
        try:
            conversation_id = request.query_params.get('conversation_id')
            if not conversation_id:
                return Response({
                    'code': 400,
                    'message': '缺少conversation_id参数',
                    'data': None
                }, status=status.HTTP_400_BAD_REQUEST)

            # 检查对话是否存在
            messages = self.get_queryset().filter(
                conversation_id=conversation_id,
                is_deleted=False,
                user=request.user
            ).order_by('created_at')
            
            if not messages.exists():
                return Response({
                    'code': 404,
                    'message': '对话不存在或无权访问',
                    'data': None
                }, status=status.HTTP_404_NOT_FOUND)
            
            # 检查是否有自定义标题参数
            custom_title = request.query_params.get('title')
            if not custom_title:
                return Response({
                    'code': 400,
                    'message': '缺少title参数',
                    'data': None
                }, status=status.HTTP_400_BAD_REQUEST)
            
            # 更新所有相关记录的标题
            ChatHistory.objects.filter(
                conversation_id=conversation_id,
                user=request.user
            ).update(title=custom_title)
            
            return Response({
                'code': 200,
                'message': '更新会话标题成功',
                'data': {
                    'conversation_id': conversation_id,
                    'title': custom_title
                }
            })

        except Exception as e:
            logger.error(f"更新会话标题失败: {str(e)}")
            logger.error(traceback.format_exc())
            return Response({
                'code': 500,
                'message': f"更新会话标题失败: {str(e)}",
                'data': None
            }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

    @action(detail=False, methods=['get'])
    def get_creator_by_id(self, request):
        """根据ID获取单个达人信息"""
        try:
            creator_id = request.query_params.get('id')
            if not creator_id:
                return Response({
                    'code': 400,
                    'message': '缺少必要参数: id',
                    'data': None
                }, status=status.HTTP_400_BAD_REQUEST)
            
            try:
                creator = CreatorProfile.objects.get(id=creator_id)
            except CreatorProfile.DoesNotExist:
                return Response({
                    'code': 404,
                    'message': '未找到该达人信息',
                    'data': None
                }, status=status.HTTP_404_NOT_FOUND)
            
            # 处理头像URL
            avatar_url = creator.get_avatar_url()
            if avatar_url and request:
                if creator.avatar:
                    avatar_url = request.build_absolute_uri(avatar_url)
            
            # 组装返回数据
            result = {
                'id': creator.id,
                'name': creator.name,
                'avatar_url': avatar_url,
                'category': creator.category,
                'mcn': creator.mcn if creator.mcn else '--',
                'pricing': f"${creator.pricing}/video" if creator.pricing else '--',
                'collab': creator.e_commerce_platforms if creator.e_commerce_platforms else []
            }
            
            return Response({
                'code': 200,
                'message': '获取成功',
                'data': result
            })
            
        except Exception as e:
            logger.error(f"获取达人信息失败: {str(e)}")
            logger.error(traceback.format_exc())
            return Response({
                'code': 500,
                'message': f'获取达人信息失败: {str(e)}',
                'data': None
            }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)