"""LLM配置服务 - 从数据库读取默认配置"""

from typing import Optional, Dict, Any, List
from sqlalchemy.orm import Session
from sqlalchemy import and_, select

from ..models.llm_config import LLMConfig
from ..db.database import get_session
from loguru import logger

class LLMConfigService:
    """LLM配置管理服务"""
    
    async def get_default_chat_config(self, session: Session) -> Optional[LLMConfig]:
        """获取默认对话模型配置"""
        # async for session in get_session():
        try:
            stmt = select(LLMConfig).where(
                and_(
                    LLMConfig.is_default == True,
                    LLMConfig.is_embedding == False,
                    LLMConfig.is_active == True
                )
            )
            config = (await session.execute(stmt)).scalar_one_or_none()
            
            if not config:
                logger.warning("未找到默认对话模型配置")
                return None
            
            return config
            
        except Exception as e:
            logger.error(f"获取默认对话模型配置失败: {str(e)}")
            return None
    
    async def get_default_embedding_config(self, session: Session) -> Optional[LLMConfig]:
        """获取默认嵌入模型配置，如果没有默认配置则尝试使用任何激活的嵌入模型配置"""
        if session is None:
            logger.error("get_default_embedding_config: session 为 None，无法查询配置")
            return None
            
        try:
            # 首先尝试获取默认嵌入模型配置
            stmt = select(LLMConfig).where(
                and_(
                    LLMConfig.is_default == True,
                    LLMConfig.is_embedding == True,
                    LLMConfig.is_active == True
                )
            )
            config = (await session.execute(stmt)).scalar_one_or_none()
            
            if config:
                session.desc = f"找到默认嵌入模型配置: {config.name} (ID: {config.id})"
                return config
            
            # 如果没有默认配置，尝试获取任何激活的嵌入模型配置作为后备
            session.desc = "未找到默认嵌入模型配置，尝试查找任何激活的嵌入模型配置"
            logger.info("未找到默认嵌入模型配置，尝试查找任何激活的嵌入模型配置")
            
            stmt = select(LLMConfig).where(
                and_(
                    LLMConfig.is_embedding == True,
                    LLMConfig.is_active == True
                )
            ).order_by(LLMConfig.created_at)  # 按创建时间排序，取第一个
            
            config = (await session.execute(stmt)).scalar_one_or_none()
            
            if config:
                session.desc = f"使用激活的嵌入模型配置（非默认）: {config.name} (ID: {config.id})"
                logger.info(f"使用激活的嵌入模型配置（非默认）: {config.name} (ID: {config.id})")
                return config
            
            # 如果还是没找到，记录详细信息
            session.desc = "ERROR: 未找到任何激活的嵌入模型配置"
            logger.error("未找到任何激活的嵌入模型配置")
            
            # 尝试查询所有嵌入模型配置（包括未激活的），用于调试
            all_embedding_stmt = select(LLMConfig).where(LLMConfig.is_embedding == True)
            all_embedding = (await session.execute(all_embedding_stmt)).scalars().all()
            if all_embedding:
                logger.warning(f"找到 {len(all_embedding)} 个嵌入模型配置，但都不是激活状态:")
                for cfg in all_embedding:
                    logger.warning(f"  - {cfg.name} (ID: {cfg.id}, is_active={cfg.is_active}, is_default={cfg.is_default})")
            else:
                logger.warning("数据库中没有任何嵌入模型配置")
            
            return None
            
        except Exception as e:
            session.desc = f"ERROR: 获取嵌入模型配置失败: {str(e)}"
            logger.error(f"获取嵌入模型配置失败: {str(e)}", exc_info=True)
            return None
    
    async def get_config_by_id(self, config_id: int) -> Optional[LLMConfig]:
        """根据ID获取配置"""
        try:
            stmt = select(LLMConfig).where(LLMConfig.id == config_id)
            return (await self.db.execute(stmt)).scalar_one_or_none()
        except Exception as e:
            logger.error(f"获取配置失败: {str(e)}")
            return None
    
    def get_active_configs(self, is_embedding: Optional[bool] = None) -> List[LLMConfig]:
        """获取所有激活的配置"""
        try:
            stmt = select(LLMConfig).where(LLMConfig.is_active == True)
            
            if is_embedding is not None:
                stmt = stmt.where(LLMConfig.is_embedding == is_embedding)
            
            stmt = stmt.order_by(LLMConfig.created_at)
            return self.db.execute(stmt).scalars().all()
            
        except Exception as e:
            logger.error(f"获取激活配置失败: {str(e)}")
            return []
    
    async def _get_fallback_chat_config(self) -> Dict[str, Any]:
        """获取fallback对话模型配置（从环境变量）"""
        from ..core.config import get_settings
        settings = get_settings()
        return await settings.llm.get_current_config()
    
    async def _get_fallback_embedding_config(self) -> Dict[str, Any]:
        """获取fallback嵌入模型配置（从环境变量）"""
        from ..core.config import get_settings
        settings = get_settings()
        return await settings.embedding.get_current_config()
    
    def test_config(self, config_id: int, test_message: str = "Hello") -> Dict[str, Any]:
        """测试配置连接"""
        try:
            config = self.get_config_by_id(config_id)
            if not config:
                return {"success": False, "error": "配置不存在"}
            
            # 这里可以添加实际的连接测试逻辑
            # 例如发送一个简单的请求来验证配置是否有效
            
            return {"success": True, "message": "配置测试成功"}
            
        except Exception as e:
            logger.error(f"测试配置失败: {str(e)}")
            return {"success": False, "error": str(e)}

# # 全局实例
# _llm_config_service = None

# def get_llm_config_service(db_session: Optional[Session] = None) -> LLMConfigService:
#     """获取LLM配置服务实例"""
#     global _llm_config_service
#     if _llm_config_service is None or db_session is not None:
#         _llm_config_service = LLMConfigService(db_session)
#     return _llm_config_service