"""
BacktestReport - 标准化回测报告

将 BacktestResult 格式化输出为文本/JSON。
"""

import json
from typing import Optional, TYPE_CHECKING

if TYPE_CHECKING:
    from data_platform.backtest_runner import BacktestResult


class BacktestReport:
    """回测报告生成器"""

    def __init__(self, result: "BacktestResult"):
        self.result = result

    def to_text(self) -> str:
        """生成文本格式报告"""
        r = self.result
        lines = [
            "=" * 60,
            f"  回测报告 | {r.strategy_name} | {r.code}",
            "=" * 60,
            f"  回测区间:   {r.start_date.date()} ~ {r.end_date.date()}",
            f"  初始资金:   {r.initial_capital:,.0f}",
            f"  最终权益:   {r.final_capital:,.0f}",
            "-" * 60,
            f"  总收益率:   {r.total_return:>8.2%}",
            f"  年化收益率: {r.annual_return:>8.2%}",
            f"  最大回撤:   {r.max_drawdown:>8.2%}",
            f"  夏普比率:   {r.sharpe_ratio:>8.2f}",
            f"  胜率:       {r.win_rate:>8.2%}",
            f"  交易次数:   {r.total_trades:>8d}",
            "-" * 60,
        ]

        if r.trades:
            lines.append(f"  {'买入日':>12s}  {'卖出日':>12s}  {'买入价':>8s}  "
                        f"{'卖出价':>8s}  {'收益率':>8s}  {'股数':>6s}")
            lines.append("  " + "-" * 68)
            for t in r.trades[:20]:
                profit_str = f"{t.profit_pct:7.2%}" if t.profit_pct is not None else "    N/A"
                lines.append(
                    f"  {t.entry_date.date()!s:>12s}  {t.exit_date.date()!s:>12s}  "
                    f"{t.entry_price:>8.2f}  {t.exit_price:>8.2f}  "
                    f"{profit_str}  {t.shares:>6d}"
                )
            if len(r.trades) > 20:
                lines.append(f"  ... 共 {len(r.trades)} 条，仅显示前20条")

        lines.append("=" * 60)
        return "\n".join(lines)

    def to_dict(self) -> dict:
        """导出为字典"""
        r = self.result
        return {
            "strategy": r.strategy_name,
            "code": r.code,
            "start_date": str(r.start_date.date()),
            "end_date": str(r.end_date.date()),
            "initial_capital": r.initial_capital,
            "final_capital": round(r.final_capital, 2),
            "total_return": round(r.total_return, 4),
            "annual_return": round(r.annual_return, 4),
            "max_drawdown": round(r.max_drawdown, 4),
            "sharpe_ratio": round(r.sharpe_ratio, 2),
            "win_rate": round(r.win_rate, 4),
            "total_trades": r.total_trades,
        }

    def to_json(self, indent: int = 2) -> str:
        """导出为JSON"""
        return json.dumps(self.to_dict(), indent=indent, ensure_ascii=False)