# apps/common/services/chat_service.py
import logging
import json
from uuid import uuid4
from django.db import transaction
from apps.accounts.models import User
from apps.knowledge_base.models import KnowledgeBase
from apps.chat.models import ChatHistory
from apps.permissions.services.permission_service import KnowledgeBasePermissionMixin

logger = logging.getLogger(__name__)

class ChatService(KnowledgeBasePermissionMixin):
    @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}")

            # 处理知识库ID
            dataset_ids = []
            if 'dataset_id' in data:
                dataset_ids.append(str(data['dataset_id']))
            elif 'dataset_id_list' in data:
                if isinstance(data['dataset_id_list'], str):
                    try:
                        dataset_list = json.loads(data['dataset_id_list'])
                        dataset_ids = [str(id) for id in dataset_list if isinstance(dataset_list, list)]
                    except json.JSONDecodeError:
                        dataset_ids = [str(data['dataset_id_list'])]
                else:
                    dataset_ids = [str(id) for id in data['dataset_id_list']]
            
            if not dataset_ids:
                raise ValueError("缺少必填字段: dataset_id 或 dataset_id_list")

            # 验证知识库权限
            knowledge_bases = []
            external_id_list = []
            for kb_id in dataset_ids:
                knowledge_base = KnowledgeBase.objects.filter(id=kb_id).first()
                if not knowledge_base:
                    raise ValueError(f"知识库不存在: {kb_id}")
                
                if not self.check_knowledge_base_permission(knowledge_base, user, 'read'):
                    raise ValueError(f"无权访问知识库: {knowledge_base.name}")
                
                knowledge_bases.append(knowledge_base)
                if knowledge_base.external_id:
                    external_id_list.append(str(knowledge_base.external_id))

            # 创建metadata
            metadata = {
                'model_id': data.get('model_id', '7a214d0e-e65e-11ef-9f4a-0242ac120006'),
                'dataset_id_list': dataset_ids,
                'dataset_external_id_list': external_id_list,
                'dataset_names': [kb.name for kb in knowledge_bases]
            }

            # 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=knowledge_bases[0],  # 使用第一个知识库
                conversation_id=conversation_id,
                title=title,
                role='user',
                content=data['question'],
                metadata=metadata
            )

            return question_record, conversation_id, metadata, knowledge_bases, external_id_list

        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:
            # 获取用户有权限的知识库ID
            accessible_kb_ids = [
                kb.id for kb in KnowledgeBase.objects.all()
                if self.check_knowledge_base_permission(kb, user, 'read')
            ]

            # 查询会话记录
            messages = ChatHistory.objects.filter(
                conversation_id=conversation_id,
                is_deleted=False
            ).filter(
                Q(user=user) | Q(knowledge_base_id__in=accessible_kb_ids)
            ).order_by('created_at')

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

            # 获取知识库信息
            first_message = messages.first()
            dataset_info = []
            if first_message and first_message.metadata and 'dataset_id_list' in first_message.metadata:
                datasets = KnowledgeBase.objects.filter(id__in=first_message.metadata['dataset_id_list'])
                accessible_datasets = [
                    ds for ds in datasets if self.check_knowledge_base_permission(ds, user, 'read')
                ]
                dataset_info = [
                    {'id': str(ds.id), 'name': ds.name, 'type': ds.type}
                    for ds in accessible_datasets
                ]

            # 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,
                'datasets': dataset_info,
                'messages': message_list
            }

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