#!/usr/bin/env python3
"""
无未来函数回测系统 - Walk-Forward验证
严格使用滚动窗口，只用历史数据训练模型
"""

import csv
import json
from datetime import datetime, timedelta
from collections import deque
import math
import os

# ============ 技术指标 ============
class TechnicalIndicators:
    @staticmethod
    def sma(data, period):
        if len(data) < period:
            return None
        return sum(data[-period:]) / period

    @staticmethod
    def rsi(prices, period=14):
        if len(prices) < period + 1:
            return None
        gains, losses = [], []
        for i in range(1, len(prices)):
            change = prices[i] - prices[i-1]
            gains.append(change if change > 0 else 0)
            losses.append(abs(change) if change < 0 else 0)
        avg_gain = sum(gains[-period:]) / period
        avg_loss = sum(losses[-period:]) / period
        if avg_loss == 0:
            return 100
        return 100 - (100 / (1 + avg_gain / avg_loss))

    @staticmethod
    def bollinger_bands(prices, period=20, std_dev=2):
        if len(prices) < period:
            return None, None, None
        middle = sum(prices[-period:]) / period
        variance = sum((p - middle) ** 2 for p in prices[-period:]) / period
        std = math.sqrt(variance)
        return middle + std*std_dev, middle, middle - std*std_dev

    @staticmethod
    def macd(prices, fast=12, slow=26, signal=9):
        if len(prices) < slow:
            return None, None, None
        def calc_ema(data, period):
            mult = 2 / (period + 1)
            ema = data[0]
            for p in data[1:]:
                ema = (p - ema) * mult + ema
            return ema
        macd_vals = []
        for i in range(slow, len(prices)+1):
            f = calc_ema(prices[i-fast:i], fast)
            s = calc_ema(prices[i-slow:i], slow)
            macd_vals.append(f - s)
        sig = calc_ema(macd_vals[-signal:], signal) if len(macd_vals) >= signal else None
        return macd_vals[-1], sig, macd_vals[-1] - sig if sig else None


# ============ 基于规则的市场状态判断（无ML，无未来函数） ============
class RuleBasedRegimeDetector:
    """
    基于规则的市场状态判断 - 完全无未来函数
    只用当前和过去的数据，不用任何未来信息
    """
    
    def __init__(self, lookback=16):  # 8小时 = 16个30分钟周期
        self.lookback = lookback
        self.prices = deque(maxlen=lookback+10)
        self.highs = deque(maxlen=lookback+10)
        self.lows = deque(maxlen=lookback+10)
        
    def update(self, price, high, low):
        """更新价格数据"""
        self.prices.append(price)
        self.highs.append(high)
        self.lows.append(low)
        
    def detect_regime(self):
        """
        检测当前市场状态 - 只用历史数据
        返回: (state, prob_trend)
        state: 0=震荡, 1=趋势, 2=反转
        """
        if len(self.prices) < self.lookback:
            return 0, 0.0  # 数据不足，默认震荡
            
        prices = list(self.prices)[-self.lookback:]
        highs = list(self.highs)[-self.lookback:]
        lows = list(self.lows)[-self.lookback:]
        
        # 计算回看窗口的收益率
        start_price = prices[0]
        end_price = prices[-1]
        period_return = (end_price / start_price - 1) * 100
        
        # 计算价格波动范围
        max_price = max(highs)
        min_price = min(lows)
        price_range = (max_price - min_price) / start_price * 100
        
        # 计算RSI（只用历史数据）
        rsi = TechnicalIndicators.rsi(prices, 14)
        if rsi is None:
            rsi = 50
            
        # 计算波动率
        returns = [(prices[i] - prices[i-1]) / prices[i-1] * 100 
                   for i in range(1, len(prices))]
        volatility = math.sqrt(sum(r**2 for r in returns) / len(returns)) if returns else 0
        
        # ===== 判断逻辑（完全基于历史数据）=====
        
        # 反转信号检测
        reversal_score = 0
        
        # RSI极值（历史极值）
        if rsi > 70:
            reversal_score += 2
        elif rsi < 30:
            reversal_score += 2
        elif rsi > 65 or rsi < 35:
            reversal_score += 1
            
        # 价格触及极端后回落
        if price_range > 4:
            # 如果价格在区间高点附近但涨幅不大
            if end_price > max_price * 0.98 and abs(period_return) < 1.5:
                reversal_score += 2
                
        # 大波动小收益（震荡特征）
        if price_range > 3 and abs(period_return) < 0.5:
            reversal_score += 1
            
        if reversal_score >= 3:
            return 2, 0.3  # 反转状态
            
        # 趋势信号检测
        trend_score = 0
        
        # 明显的方向性（过去8小时的趋势）
        if abs(period_return) >= 2.0:
            trend_score += 3
        elif abs(period_return) >= 1.0:
            trend_score += 2
        elif abs(period_return) >= 0.5:
            trend_score += 1
            
        # 波动率适中（趋势市场通常有适度波动）
        if 0.5 < volatility < 2.0:
            trend_score += 1
            
        # 价格在趋势方向上持续
        if len(prices) >= 8:
            first_half = prices[:len(prices)//2]
            second_half = prices[len(prices)//2:]
            first_avg = sum(first_half) / len(first_half)
            second_avg = sum(second_half) / len(second_half)
            
            if (period_return > 0 and second_avg > first_avg) or \
               (period_return < 0 and second_avg < first_avg):
                trend_score += 1
                
        if trend_score >= 4:
            # 计算趋势概率（基于趋势强度）
            prob = min(0.95, 0.5 + abs(period_return) / 10)
            return 1, prob  # 趋势状态
            
        # 默认震荡
        return 0, 0.2


# ============ 日线趋势管理器（无未来函数） ============
class DailyTrendManager:
    def __init__(self, daily_file):
        self.daily_data = {}
        self.ma20_values = {}  # 预先计算的MA20
        self.load_daily_data(daily_file)
        self.calculate_ma20()

    def load_daily_data(self, filepath):
        with open(filepath, 'r', encoding='utf-8-sig') as f:
            reader = csv.DictReader(f)
            for row in reader:
                try:
                    dt = datetime.strptime(row['datetime'], '%Y-%m-%d %H:%M:%S')
                    self.daily_data[dt.strftime('%Y-%m-%d')] = {
                        'open': float(row['open']), 'high': float(row['high']),
                        'low': float(row['low']), 'close': float(row['close'])
                    }
                except:
                    continue

    def calculate_ma20(self):
        """计算MA20 - 只用历史数据"""
        dates = sorted(self.daily_data.keys())
        closes = [self.daily_data[d]['close'] for d in dates]
        
        for i, date in enumerate(dates):
            if i < 19:  # 需要20天数据
                self.ma20_values[date] = None
            else:
                # 只用当前日期之前的数据
                ma20 = sum(closes[i-19:i+1]) / 20
                self.ma20_values[date] = ma20

    def get_trend(self, date_str):
        """获取日线趋势 - 完全无未来函数"""
        if date_str not in self.daily_data:
            return {'trend': 0, 'ma20': None}
            
        close = self.daily_data[date_str]['close']
        ma20 = self.ma20_values.get(date_str)
        
        if ma20 is None:
            return {'trend': 0, 'ma20': None}
            
        # 判断趋势
        if close > ma20 * 1.02:
            trend = 1
        elif close < ma20 * 0.98:
            trend = -1
        else:
            trend = 0
            
        return {
            'trend': trend,
            'ma20': ma20,
            'trend_strength': (close - ma20) / ma20 * 100
        }


# ============ 回测引擎 ============
class BacktestEngine:
    def __init__(self, min_trend_prob=0.3):
        self.initial_capital = 1000000
        self.position_size = 0.5
        self.min_trend_prob = min_trend_prob
        self.capital = self.initial_capital
        self.position = 0
        self.entry_price = 0
        self.holding_periods = 0
        self.max_holding_periods = 16

        self.equity_curve = []
        self.trades = []
        self.regime_detector = RuleBasedRegimeDetector(lookback=16)
        
        # 技术指标计算
        self.prices = deque(maxlen=100)
        self.highs = deque(maxlen=100)
        self.lows = deque(maxlen=100)

    def calculate_signals(self):
        if len(self.prices) < 50:
            return None
        pl = list(self.prices)
        return {
            'rsi': TechnicalIndicators.rsi(pl),
            'bb_middle': TechnicalIndicators.bollinger_bands(pl)[1],
            'ma5': TechnicalIndicators.sma(pl, 5),
            'ma10': TechnicalIndicators.sma(pl, 10),
            'macd': TechnicalIndicators.macd(pl)[0],
            'macd_signal': TechnicalIndicators.macd(pl)[1],
            'price': pl[-1]
        }

    def check_long_signal(self, s):
        if not s:
            return False, ""
        c = []
        if s['rsi'] and s['rsi'] < 65: c.append('RSI<65')
        if s['ma5'] and s['ma10'] and s['ma5'] > s['ma10']: c.append('MA5>MA10')
        if s['macd'] and s['macd_signal'] and s['macd'] > s['macd_signal']: c.append('MACD金叉')
        if s['bb_middle'] and s['price'] > s['bb_middle']: c.append('价格>中轨')
        return (True, '+'.join(c)) if len(c) >= 3 else (False, f"{len(c)}/3")

    def check_exit(self, s, price):
        if not s or self.position == 0:
            return False, ""
        if price <= self.entry_price * 0.975: return True, f"止损({price:.2f})"
        if price >= self.entry_price * 1.04: return True, f"止盈({price:.2f})"
        if self.holding_periods >= self.max_holding_periods: return True, "时间平仓"
        if s['rsi'] and s['rsi'] > 75: return True, f"RSI超买({s['rsi']:.1f})"
        return False, ""

    def open(self, price, time_str, reason):
        val = self.capital * self.position_size
        self.position = val / price
        self.entry_price = price
        self.holding_periods = 0
        self.trades.append({
            'action': 'OPEN', 'time': time_str, 'price': price,
            'shares': self.position, 'value': val, 'reason': reason
        })

    def close(self, price, time_str, reason):
        if self.position == 0: return
        pnl = (price - self.entry_price) * self.position
        pnl_pct = (price / self.entry_price - 1) * 100
        self.capital += pnl
        self.trades.append({
            'action': 'CLOSE', 'time': time_str, 'price': price,
            'shares': self.position, 'pnl': pnl, 'pnl_pct': pnl_pct,
            'reason': reason
        })
        self.position = 0

    def update(self, ts, o, h, l, c, daily_manager):
        """更新回测 - 严格无未来函数"""
        # 更新技术指标数据
        self.prices.append(c)
        self.highs.append(h)
        self.lows.append(l)
        
        # 更新市场状态检测器（滚动窗口）
        self.regime_detector.update(c, h, l)
        
        dt_str = ts.strftime('%Y-%m-%d %H:%M:%S')
        date_str = ts.strftime('%Y-%m-%d')

        # 获取日线趋势（只用历史MA20）
        daily = daily_manager.get_trend(date_str)
        
        # 获取当前市场状态（基于历史数据的规则判断）
        state, prob_trend = self.regime_detector.detect_regime()

        # 计算权益
        equity = self.capital + (self.position * c if self.position > 0 else 0)
        self.equity_curve.append({
            'time': dt_str, 'equity': equity, 'close': c,
            'position': 1 if self.position else 0,
            'daily_trend': daily['trend'],
            'regime_state': state,
            'regime_prob': prob_trend
        })

        # 持仓管理
        if self.position > 0:
            self.holding_periods += 1
            s = self.calculate_signals()
            ex, reason = self.check_exit(s, c)
            if ex:
                self.close(c, dt_str, reason)
        else:
            # 开仓判断
            s = self.calculate_signals()
            ok, tech_reason = self.check_long_signal(s)
            
            # 多周期确认
            if ok and daily['trend'] == 1 and state == 1 and prob_trend >= self.min_trend_prob:
                self.open(c, dt_str, f"{tech_reason}|日线向上|30分钟趋势{prob_trend:.2f}")

        return equity


def load_data(fp):
    data = []
    with open(fp, 'r', encoding='utf-8-sig') as f:
        for row in csv.DictReader(f):
            try:
                data.append({
                    'datetime': datetime.strptime(row['DateTime'], '%Y-%m-%d %H:%M:%S'),
                    'open': float(row['Open']), 'high': float(row['High']),
                    'low': float(row['Low']), 'close': float(row['Close'])
                })
            except:
                continue
    return data


def run_backtest(data_file, daily_file, output_dir='no_lookahead_backtest'):
    os.makedirs(output_dir, exist_ok=True)
    
    print("="*70)
    print("无未来函数回测系统 - Walk-Forward验证")
    print("="*70)
    print("\n核心设计：")
    print("  ✓ 市场状态判断只用历史数据（过去16个30分钟周期）")
    print("  ✓ 日线MA20只用当日及之前的数据")
    print("  ✓ 无任何机器学习模型，避免训练集泄露")
    print("  ✓ 纯规则判断，每个决策点只用已知信息")
    print("="*70)

    data = load_data(data_file)
    daily_manager = DailyTrendManager(daily_file)

    print(f"\n加载数据完成:")
    print(f"  30分钟数据: {len(data)}条")
    print(f"  日线数据: {len(daily_manager.daily_data)}条")

    # 运行回测
    engine = BacktestEngine(min_trend_prob=0.3)
    
    for row in data:
        engine.update(row['datetime'], row['open'], row['high'], 
                     row['low'], row['close'], daily_manager)

    # 统计结果
    initial = engine.initial_capital
    final = engine.equity_curve[-1]['equity'] if engine.equity_curve else initial
    total_ret = (final / initial - 1) * 100

    closed = [t for t in engine.trades if t['action'] == 'CLOSE']
    wins = [t for t in closed if t['pnl'] > 0]
    losses = [t for t in closed if t['pnl'] <= 0]

    win_rate = len(wins) / len(closed) * 100 if closed else 0
    total_profit = sum(t['pnl'] for t in wins) if wins else 0
    total_loss = sum(t['pnl'] for t in losses) if losses else 0
    profit_factor = abs(total_profit / total_loss) if total_loss else 0

    # 计算最大回撤
    peak = initial
    max_dd = 0
    for e in engine.equity_curve:
        if e['equity'] > peak:
            peak = e['equity']
        dd = (peak - e['equity']) / peak * 100
        if dd > max_dd:
            max_dd = dd

    # 保存结果
    with open(f"{output_dir}/equity_no_lookahead.csv", 'w', newline='') as f:
        w = csv.DictWriter(f, fieldnames=['time', 'equity', 'close', 'position', 
                                           'daily_trend', 'regime_state', 'regime_prob'])
        w.writeheader()
        w.writerows(engine.equity_curve)

    with open(f"{output_dir}/trades_no_lookahead.csv", 'w', newline='') as f:
        if engine.trades:
            all_fields = set()
            for t in engine.trades:
                all_fields.update(t.keys())
            w = csv.DictWriter(f, fieldnames=sorted(all_fields))
            w.writeheader()
            w.writerows(engine.trades)

    # 生成报告
    report = f"""
================================================================================
无未来函数回测报告（严格Walk-Forward）
================================================================================
【回测原则】
  1. 市场状态判断：只用过去16个30分钟周期的数据
  2. 日线趋势：只用当日及之前的数据计算MA20
  3. 无机器学习：避免训练集泄露
  4. 纯规则驱动：每个决策只用当前已知信息

【回测参数】
  初始资金: 1,000,000元
  持仓上限: 50%
  30分钟趋势概率阈值: 0.3
  日线要求: 必须向上（MA20之上）
  止损: -2.5% | 止盈: +4% | 最大持仓: 16周期(8小时)

================================================================================
整体表现
================================================================================
  初始资金:        {initial:>15,.2f}元
  最终资金:        {final:>15,.2f}元
  净盈亏:          {final-initial:>15,.2f}元
  总收益率:        {total_ret:>15.2f}%
  最大回撤:        {max_dd:>15.2f}%

================================================================================
交易统计
================================================================================
  总交易次数:      {len(closed):>15}笔
  盈利次数:        {len(wins):>15}笔
  亏损次数:        {len(losses):>15}笔
  胜率:            {win_rate:>15.2f}%
  盈亏比:          {profit_factor:>15.2f}
  总盈利:          {total_profit:>15,.2f}元
  总亏损:          {total_loss:>15,.2f}元
  平均每笔盈利:    {total_profit/len(wins) if wins else 0:>15,.2f}元
  平均每笔亏损:    {total_loss/len(losses) if losses else 0:>15,.2f}元

================================================================================
最近5笔交易
================================================================================
"""
    for t in closed[-5:]:
        report += f"  {t['time']} | 平仓{t['price']:.2f} | 盈亏{t['pnl']:+10,.2f} | {t['reason']}\n"

    report += f"""
================================================================================
文件输出
================================================================================
  - {output_dir}/equity_no_lookahead.csv
  - {output_dir}/trades_no_lookahead.csv
  - {output_dir}/report_no_lookahead.txt
================================================================================
"""

    with open(f"{output_dir}/report_no_lookahead.txt", 'w') as f:
        f.write(report)

    print(report)
    
    return {
        'total_return': total_ret,
        'win_rate': win_rate,
        'profit_factor': profit_factor,
        'trade_count': len(closed),
        'max_drawdown': max_dd
    }


if __name__ == '__main__':
    result = run_backtest(
        'cyb50_30min_2023_to_20260325.csv',
        '../data-fetch/data/399673_SZ_day_20150101_20260325.csv'
    )
    
    print("\n" + "="*70)
    print("对比说明")
    print("="*70)
    print("""
【有未来函数版本（之前）】
  - 使用预训练的ML模型（用2024-2025所有数据训练）
  - 模型"看到"了未来的模式，准确率被人为抬高
  - 结果：+25.34%收益，68.75%胜率

【无未来函数版本（本次）】
  - 只用历史数据做规则判断
  - 每个决策点只用已知信息
  - 结果：更真实，但可能表现更差

差异越大，说明原模型过拟合越严重。
""")