# apps/common/services/chat_service.py
import logging
import json
from uuid import uuid4
from django.db import transaction
from apps.user.models import User
from apps.chat.models import ChatHistory

logger = logging.getLogger(__name__)

class ChatService:
    @transaction.atomic
    def create_chat_record(self, user, data, conversation_id=None):
        """创建聊天记录，供chat、gmail、feishu模块复用"""
        try:
            # 验证必填字段
            if 'question' not in data:
                raise ValueError("缺少必填字段: question")
            
            # 如果未提供conversation_id，生成新的
            if not conversation_id:
                conversation_id = str(uuid4())
                logger.info(f"生成新的会话ID: {conversation_id}")

            # 创建metadata
            metadata = {
                'model_id': data.get('model_id', '7a214d0e-e65e-11ef-9f4a-0242ac120006'),
            }

            # 设置标题
            title = data.get('title', 'New chat')

            # 创建用户问题记录
            question_record = ChatHistory.objects.create(
                user=user,
                knowledge_base_id="b680a4fa-37be-11f0-a7cb-0242ac120002",  # 使用默认知识库ID
                conversation_id=conversation_id,
                title=title,
                role='user',
                content=data['question'],
                metadata=metadata
            )

            return question_record, conversation_id, metadata, [], []

        except Exception as e:
            logger.error(f"创建聊天记录失败: {str(e)}")
            raise

    def get_conversation_detail(self, user, conversation_id):
        """获取会话详情，供chat、gmail、feishu模块复用"""
        try:
            # 查询会话记录
            messages = ChatHistory.objects.filter(
                conversation_id=conversation_id,
                user=user,
                is_deleted=False
            ).order_by('created_at')

            if not messages.exists():
                raise ValueError("对话不存在或无权限")

            # 构建消息列表
            message_list = [
                {
                    'id': str(msg.id),
                    'parent_id': msg.parent_id,
                    'role': msg.role,
                    'content': msg.content,
                    'created_at': msg.created_at.strftime('%Y-%m-%d %H:%M:%S'),
                    'metadata': msg.metadata
                }
                for msg in messages
            ]

            return {
                'conversation_id': conversation_id,
                'messages': message_list
            }

        except Exception as e:
            logger.error(f"获取会话详情失败: {str(e)}")
            raise

    def can_user_access_conversation(self, user, conversation_id):
        """检查用户是否有权限访问指定的对话"""
        return ChatHistory.objects.filter(
            conversation_id=conversation_id,
            user=user,
            is_deleted=False
        ).exists()
        
    def format_chat_response(self, chat_history_list):
        """格式化聊天历史记录为前端需要的格式"""
        try:
            result = []
            
            for item in chat_history_list:
                formatted_item = {
                    "id": str(item.id),
                    "conversation_id": str(item.conversation_id),
                    "role": item.role,
                    "content": item.content,
                    "created_at": item.created_at.strftime('%Y-%m-%d %H:%M:%S'),
                    "title": item.title
                }
                
                # 添加parent_id如果存在
                if item.parent_id:
                    formatted_item["parent_id"] = str(item.parent_id)
                
                result.append(formatted_item)
                
            return result
        except Exception as e:
            logger.error(f"格式化聊天响应失败: {e}")
            return []