from fastapi import APIRouter, Depends, HTTPException
from typing import List, Dict, Any, Optional
import json  # 导入json模块
from sqlalchemy.orm import Session

from app.core.deps import get_db, get_current_user
from app.models.user import User
from app.models.backtest_result import BacktestResult
from app.schemas.backtest import (
    BacktestResultResponse,
    BacktestDetailResponse
)

router = APIRouter()


@router.get("/", response_model=List[BacktestResultResponse])
async def get_backtest_results(
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
    strategy_id: Optional[int] = None,
    skip: int = 0,
    limit: int = 20
):
    """获取回测结果列表"""
    filters = {"user_id": current_user.id}
    if strategy_id:
        filters["strategy_id"] = strategy_id

    results = await BacktestResult.filter(
        **filters
    ).prefetch_related("strategy").order_by(
        "-created_at"
    ).offset(skip).limit(limit).all()

    response_results = []
    for result in results:
        response_results.append({
            "id": result.id,
            "strategy_id": result.strategy_id,
            "strategy_name": result.strategy.name,
            "start_date": result.start_date,
            "end_date": result.end_date,
            "initial_capital": result.initial_capital,
            "final_capital": result.final_capital,
            "total_return": result.total_return,
            "annual_return": result.annual_return,
            "sharpe_ratio": result.sharpe_ratio,
            "max_drawdown": result.max_drawdown,
            "win_rate": result.win_rate,
            "created_at": result.created_at
        })

    return response_results


@router.get("/{backtest_id}", response_model=BacktestDetailResponse)
async def get_backtest_result(
    backtest_id: int,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """获取回测结果详情"""
    result = await BacktestResult.filter(
        id=backtest_id
    ).prefetch_related("strategy").first()
    if not result:
        raise HTTPException(status_code=404, detail="回测结果不存在")

    # 检查权限
    if result.user_id != current_user.id and not current_user.is_admin:
        raise HTTPException(status_code=403, detail="没有权限查看此回测结果")

    # 解析交易记录和每日净值数据
    trades = []
    daily_values = []

    if result.results_data:
        try:
            results_data = json.loads(result.results_data)
            trades = results_data.get("trades", [])
            daily_values = results_data.get("daily_values", [])
        except Exception:
            # 解析失败时使用空列表
            pass

    return {
        "id": result.id,
        "strategy_id": result.strategy_id,
        "strategy_name": result.strategy.name,
        "user_id": result.user_id,
        "start_date": result.start_date,
        "end_date": result.end_date,
        "initial_capital": result.initial_capital,
        "final_capital": result.final_capital,
        "total_return": result.total_return,
        "annual_return": result.annual_return,
        "sharpe_ratio": result.sharpe_ratio,
        "max_drawdown": result.max_drawdown,
        "win_rate": result.win_rate,
        "trades": trades,
        "daily_values": daily_values,
        "created_at": result.created_at
    }


@router.delete("/{backtest_id}", response_model=Dict[str, Any])
async def delete_backtest_result(
    backtest_id: int,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """删除回测结果"""
    result = await BacktestResult.get(id=backtest_id)
    if not result:
        raise HTTPException(status_code=404, detail="回测结果不存在")

    # 检查权限
    if result.user_id != current_user.id and not current_user.is_admin:
        raise HTTPException(status_code=403, detail="没有权限删除此回测结果")

    # 删除回测结果
    await result.delete()

    return {"success": True, "message": "回测结果已删除"}