from typing import Dict, Optional, List
import json
from app.services.datasource.base import DataSourceBase
from app.services.datasource.tushare import TushareSource
from app.services.datasource.akshare import AkshareSource
from app.database import SessionLocal
from app.models import DataSourceConfig


class DataSourceManager:
    """数据源管理器：管理多个数据源的注册、切换和调用"""

    _sources: Dict[str, DataSourceBase] = {}
    _source_map = {
        "tushare": TushareSource,
        "akshare": AkshareSource,
        # "ctp": CtpSource,  # 后续扩展
    }

    @classmethod
    def register(cls, name: str, source_class):
        """注册新的数据源类型"""
        cls._source_map[name] = source_class

    @classmethod
    def get_source(cls, name: str) -> Optional[DataSourceBase]:
        """获取已初始化的数据源实例"""
        return cls._sources.get(name)

    @classmethod
    def load_enabled_sources(cls):
        """从数据库加载启用的数据源"""
        db = SessionLocal()
        try:
            configs = db.query(DataSourceConfig).filter(
                DataSourceConfig.is_enabled == True
            ).order_by(DataSourceConfig.priority).all()

            for cfg in configs:
                if cfg.source_name in cls._source_map:
                    source_class = cls._source_map[cfg.source_name]
                    try:
                        config = json.loads(cfg.config_json) if cfg.config_json else {}
                    except json.JSONDecodeError:
                        config = {}
                    source = source_class(config)
                    cls._sources[cfg.source_name] = source
        finally:
            db.close()

    @classmethod
    def get_primary_source(cls) -> Optional[DataSourceBase]:
        """获取优先级最高的已启用数据源"""
        if not cls._sources:
            cls.load_enabled_sources()

        # 按优先级排序
        db = SessionLocal()
        try:
            primary_cfg = db.query(DataSourceConfig).filter(
                DataSourceConfig.is_enabled == True
            ).order_by(DataSourceConfig.priority).first()

            if primary_cfg and primary_cfg.source_name in cls._sources:
                return cls._sources[primary_cfg.source_name]
            return None
        finally:
            db.close()

    @classmethod
    def get_all_sources_status(cls) -> List[dict]:
        """获取所有数据源状态"""
        db = SessionLocal()
        try:
            configs = db.query(DataSourceConfig).all()
            result = []
            for cfg in configs:
                # 解析 config_json
                try:
                    config_json = json.loads(cfg.config_json) if cfg.config_json else {}
                except json.JSONDecodeError:
                    config_json = {}
                    
                status = {
                    "source_name": cfg.source_name,
                    "display_name": cfg.display_name,
                    "is_enabled": cfg.is_enabled,
                    "priority": cfg.priority,
                    "status": cfg.status,
                    "error_msg": cfg.error_msg,
                    "last_sync_time": cfg.last_sync_time,
                    "config_json": config_json,
                }
                result.append(status)
            return result
        finally:
            db.close()