# 换月预警模块
import pandas as pd
import numpy as np
from datetime import datetime, timedelta
from typing import Dict, List, Optional, Tuple


class RolloverDetector:
    """换月预警检测器"""
    
    def __init__(self):
        pass
    
    def analyze_rollover(self, symbol: str, data: pd.DataFrame, contract_info: Optional[Dict] = None) -> Dict:
        """分析换月情况"""
        result = {}
        
        # 检测交割日
        delivery_info = self._detect_delivery_date(symbol, contract_info)
        result.update(delivery_info)
        
        # 分析流动性
        liquidity_analysis = self._analyze_liquidity(data)
        result.update(liquidity_analysis)
        
        # 分析价差
        spread_analysis = self._analyze_spread(symbol)
        result.update(spread_analysis)
        
        # 生成换月预警
        rollover_warning = self._generate_rollover_warning(delivery_info, liquidity_analysis)
        result['rollover_warning'] = rollover_warning
        
        # 生成减仓建议
        position_adjustment = self._generate_position_adjustment(delivery_info, liquidity_analysis)
        result['position_adjustment'] = position_adjustment
        
        return result
    
    def _detect_delivery_date(self, symbol: str, contract_info: Optional[Dict] = None) -> Dict:
        """检测交割日"""
        if contract_info and 'expire_datetime' in contract_info:
            # 使用合约信息中的交割日
            expire_timestamp = contract_info['expire_datetime']
            if isinstance(expire_timestamp, int):
                # 处理纳秒时间戳
                if expire_timestamp > 1e15:
                    expire_date = datetime.fromtimestamp(expire_timestamp / 1e9)
                else:
                    expire_date = datetime.fromtimestamp(expire_timestamp)
            else:
                expire_date = pd.to_datetime(expire_timestamp)
        else:
            # 基于合约代码推断交割日
            expire_date = self._infer_delivery_date(symbol)
        
        # 计算距离交割日的天数
        today = datetime.now()
        days_to_delivery = (expire_date - today).days
        
        # 确定换月预警级别
        warning_level = self._calculate_warning_level(days_to_delivery)
        
        return {
            'expire_date': expire_date.strftime('%Y-%m-%d'),
            'days_to_delivery': days_to_delivery,
            'warning_level': warning_level
        }
    
    def _infer_delivery_date(self, symbol: str) -> datetime:
        """基于合约代码推断交割日"""
        # 简化的合约代码解析
        # 假设合约代码格式为：品种+年份+月份，如 'CU2309'
        try:
            # 提取年份和月份
            year_str = symbol[-4:-2]
            month_str = symbol[-2:]
            
            # 构建年份（加上世纪）
            year = 2000 + int(year_str)
            month = int(month_str)
            
            # 假设交割日为合约月份的15日
            # 实际交割日可能因品种而异，这里使用简化处理
            expire_date = datetime(year, month, 15)
            
            return expire_date
        except Exception:
            # 如果解析失败，返回60天后的日期
            return datetime.now() + timedelta(days=60)
    
    def _calculate_warning_level(self, days_to_delivery: int) -> str:
        """计算换月预警级别"""
        if days_to_delivery <= 3:
            return 'critical'
        elif days_to_delivery <= 7:
            return 'high'
        elif days_to_delivery <= 15:
            return 'medium'
        elif days_to_delivery <= 30:
            return 'low'
        else:
            return 'none'
    
    def _analyze_liquidity(self, data: pd.DataFrame) -> Dict:
        """分析流动性"""
        # 计算成交量指标
        avg_volume = data['volume'].tail(20).mean()
        volume_trend = self._analyze_volume_trend(data['volume'])
        
        # 计算持仓量指标
        avg_open_interest = data['open_interest'].tail(20).mean()
        oi_trend = self._analyze_oi_trend(data['open_interest'])
        
        # 计算买卖价差（简化处理）
        # 实际应该使用Tick数据计算
        bid_ask_spread = self._estimate_bid_ask_spread(data)
        
        # 计算流动性评分
        liquidity_score = self._calculate_liquidity_score(avg_volume, volume_trend, avg_open_interest, oi_trend, bid_ask_spread)
        
        # 确定流动性风险级别
        liquidity_risk = self._calculate_liquidity_risk(liquidity_score)
        
        return {
            'avg_volume': avg_volume,
            'volume_trend': volume_trend,
            'avg_open_interest': avg_open_interest,
            'oi_trend': oi_trend,
            'bid_ask_spread': bid_ask_spread,
            'liquidity_score': liquidity_score,
            'liquidity_risk': liquidity_risk
        }
    
    def _analyze_volume_trend(self, volume_series: pd.Series) -> str:
        """分析成交量趋势"""
        if len(volume_series) < 10:
            return 'stable'
        
        # 计算短期和长期移动平均线
        short_ma = volume_series.tail(10).mean()
        long_ma = volume_series.tail(30).mean()
        
        if short_ma > long_ma * 1.1:
            return 'increasing'
        elif short_ma < long_ma * 0.9:
            return 'decreasing'
        else:
            return 'stable'
    
    def _analyze_oi_trend(self, oi_series: pd.Series) -> str:
        """分析持仓量趋势"""
        if len(oi_series) < 10:
            return 'stable'
        
        # 计算短期和长期移动平均线
        short_ma = oi_series.tail(10).mean()
        long_ma = oi_series.tail(30).mean()
        
        if short_ma > long_ma * 1.1:
            return 'increasing'
        elif short_ma < long_ma * 0.9:
            return 'decreasing'
        else:
            return 'stable'
    
    def _estimate_bid_ask_spread(self, data: pd.DataFrame) -> float:
        """估算买卖价差"""
        # 简化处理，使用收盘价的波动来估算
        price_volatility = data['close'].tail(20).std()
        # 假设价差为波动率的10%
        return price_volatility * 0.1
    
    def _calculate_liquidity_score(self, avg_volume: float, volume_trend: str, 
                                  avg_open_interest: float, oi_trend: str, 
                                  bid_ask_spread: float) -> float:
        """计算流动性评分"""
        # 基础分数
        base_score = 100
        
        # 成交量因素
        if avg_volume < 1000:
            base_score -= 30
        elif avg_volume < 5000:
            base_score -= 15
        
        # 成交量趋势因素
        if volume_trend == 'decreasing':
            base_score -= 20
        elif volume_trend == 'increasing':
            base_score += 10
        
        # 持仓量因素
        if avg_open_interest < 5000:
            base_score -= 20
        elif avg_open_interest < 20000:
            base_score -= 10
        
        # 持仓量趋势因素
        if oi_trend == 'decreasing':
            base_score -= 15
        elif oi_trend == 'increasing':
            base_score += 5
        
        # 买卖价差因素
        if bid_ask_spread > 0.5:
            base_score -= 25
        elif bid_ask_spread > 0.2:
            base_score -= 10
        
        # 确保分数在0-100之间
        return max(0, min(100, base_score))
    
    def _calculate_liquidity_risk(self, liquidity_score: float) -> str:
        """计算流动性风险"""
        if liquidity_score < 30:
            return 'high'
        elif liquidity_score < 60:
            return 'medium'
        else:
            return 'low'
    
    def _analyze_spread(self, symbol: str) -> Dict:
        """分析价差"""
        # 简化处理，实际应该比较当前合约和下一个合约的价差
        # 这里返回模拟数据
        return {
            'current_next_spread': 5.2,
            'spread_trend': 'stable',
            'spread_ratio': 0.0015
        }
    
    def _generate_rollover_warning(self, delivery_info: Dict, liquidity_info: Dict) -> Dict:
        """生成换月预警"""
        warning_level = delivery_info['warning_level']
        liquidity_risk = liquidity_info['liquidity_risk']
        
        # 综合预警
        overall_warning = 'none'
        if warning_level in ['critical', 'high'] or liquidity_risk == 'high':
            overall_warning = 'high'
        elif warning_level == 'medium' or liquidity_risk == 'medium':
            overall_warning = 'medium'
        elif warning_level == 'low':
            overall_warning = 'low'
        
        # 预警信息
        warning_message = self._generate_warning_message(warning_level, liquidity_risk)
        
        # 建议操作
        recommended_actions = self._generate_recommended_actions(warning_level, liquidity_risk)
        
        return {
            'overall_warning': overall_warning,
            'warning_message': warning_message,
            'recommended_actions': recommended_actions
        }
    
    def _generate_warning_message(self, warning_level: str, liquidity_risk: str) -> str:
        """生成预警信息"""
        messages = []
        
        if warning_level == 'critical':
            messages.append('合约即将到期，距离交割日不足3天')
        elif warning_level == 'high':
            messages.append('合约接近到期，距离交割日不足7天')
        elif warning_level == 'medium':
            messages.append('合约距离交割日不足15天，建议开始关注换月')
        
        if liquidity_risk == 'high':
            messages.append('流动性风险较高，可能影响交易执行')
        elif liquidity_risk == 'medium':
            messages.append('流动性风险中等，建议谨慎交易')
        
        if not messages:
            return '合约状态正常，无需特殊关注'
        
        return '; '.join(messages)
    
    def _generate_recommended_actions(self, warning_level: str, liquidity_risk: str) -> List[str]:
        """生成建议操作"""
        actions = []
        
        if warning_level in ['critical', 'high']:
            actions.append('立即开始换月操作')
            actions.append('逐步减仓当前合约')
            actions.append('在新合约建立相应仓位')
        elif warning_level == 'medium':
            actions.append('开始评估换月时机')
            actions.append('关注新合约流动性')
        
        if liquidity_risk == 'high':
            actions.append('减小单笔交易规模')
            actions.append('使用限价单而非市价单')
            actions.append('考虑提前换月')
        
        return actions
    
    def _generate_position_adjustment(self, delivery_info: Dict, liquidity_info: Dict) -> Dict:
        """生成仓位调整建议"""
        days_to_delivery = delivery_info['days_to_delivery']
        warning_level = delivery_info['warning_level']
        liquidity_risk = liquidity_info['liquidity_risk']
        
        # 计算减仓比例
        reduction_ratio = self._calculate_reduction_ratio(days_to_delivery, warning_level, liquidity_risk)
        
        # 计算建议的减仓时间表
        reduction_schedule = self._generate_reduction_schedule(days_to_delivery, reduction_ratio)
        
        # 计算新合约建仓建议
        new_contract_adjustment = self._generate_new_contract_adjustment(reduction_ratio)
        
        return {
            'reduction_ratio': reduction_ratio,
            'reduction_schedule': reduction_schedule,
            'new_contract_adjustment': new_contract_adjustment
        }
    
    def _calculate_reduction_ratio(self, days_to_delivery: int, warning_level: str, liquidity_risk: str) -> float:
        """计算减仓比例"""
        # 基础减仓比例
        base_ratio = 0.0
        
        if warning_level == 'critical':
            base_ratio = 0.9  # 减仓90%
        elif warning_level == 'high':
            base_ratio = 0.7  # 减仓70%
        elif warning_level == 'medium':
            base_ratio = 0.4  # 减仓40%
        elif warning_level == 'low':
            base_ratio = 0.2  # 减仓20%
        
        # 流动性风险调整
        if liquidity_risk == 'high':
            base_ratio = min(1.0, base_ratio + 0.2)
        elif liquidity_risk == 'medium':
            base_ratio = min(1.0, base_ratio + 0.1)
        
        return base_ratio
    
    def _generate_reduction_schedule(self, days_to_delivery: int, reduction_ratio: float) -> List[Dict]:
        """生成减仓时间表"""
        schedule = []
        
        if days_to_delivery <= 3:
            # 紧急减仓
            schedule.append({
                'timeframe': '今日',
                'reduction_ratio': reduction_ratio
            })
        elif days_to_delivery <= 7:
            # 快速减仓
            daily_ratio = reduction_ratio / 3
            for i in range(3):
                schedule.append({
                    'timeframe': f'{i+1}天内',
                    'reduction_ratio': daily_ratio
                })
        elif days_to_delivery <= 15:
            # 逐步减仓
            daily_ratio = reduction_ratio / 5
            for i in range(5):
                schedule.append({
                    'timeframe': f'{i+1}天内',
                    'reduction_ratio': daily_ratio
                })
        elif days_to_delivery <= 30:
            # 缓慢减仓
            weekly_ratio = reduction_ratio / 2
            schedule.append({
                'timeframe': '第一周',
                'reduction_ratio': weekly_ratio
            })
            schedule.append({
                'timeframe': '第二周',
                'reduction_ratio': weekly_ratio
            })
        
        return schedule
    
    def _generate_new_contract_adjustment(self, reduction_ratio: float) -> Dict:
        """生成新合约建仓建议"""
        # 建议在新合约建立与原合约相同方向的仓位
        # 建仓比例应与减仓比例对应
        return {
            'direction': 'same_as_current',
            'target_ratio': reduction_ratio,
            'execution_strategy': 'gradual',
            'considerations': [
                '关注新合约流动性',
                '注意合约间价差',
                '避免在换月高峰期交易'
            ]
        }
    
    def monitor_rollover_risk(self, symbol: str, data: pd.DataFrame, position_size: float) -> Dict:
        """监控换月风险"""
        # 分析换月情况
        rollover_analysis = self.analyze_rollover(symbol, data)
        
        # 计算风险暴露
        risk_exposure = self._calculate_risk_exposure(position_size, rollover_analysis)
        
        # 生成风险报告
        risk_report = {
            'symbol': symbol,
            'position_size': position_size,
            'rollover_analysis': rollover_analysis,
            'risk_exposure': risk_exposure,
            'timestamp': datetime.now().strftime('%Y-%m-%d %H:%M:%S')
        }
        
        return risk_report
    
    def _calculate_risk_exposure(self, position_size: float, rollover_analysis: Dict) -> Dict:
        """计算风险暴露"""
        warning_level = rollover_analysis['warning_level']
        liquidity_risk = rollover_analysis.get('liquidity_risk', 'low')
        
        # 基础风险分数
        base_risk = 0
        
        if warning_level == 'critical':
            base_risk = 90
        elif warning_level == 'high':
            base_risk = 70
        elif warning_level == 'medium':
            base_risk = 40
        elif warning_level == 'low':
            base_risk = 20
        
        # 流动性风险调整
        if liquidity_risk == 'high':
            base_risk += 20
        elif liquidity_risk == 'medium':
            base_risk += 10
        
        # 仓位大小调整
        if position_size > 10:
            base_risk += 15
        elif position_size > 5:
            base_risk += 5
        
        # 确保风险分数在0-100之间
        risk_score = max(0, min(100, base_risk))
        
        # 风险等级
        risk_level = 'low'
        if risk_score >= 80:
            risk_level = 'critical'
        elif risk_score >= 60:
            risk_level = 'high'
        elif risk_score >= 30:
            risk_level = 'medium'
        
        return {
            'risk_score': risk_score,
            'risk_level': risk_level,
            'recommendations': self._generate_risk_recommendations(risk_level)
        }
    
    def _generate_risk_recommendations(self, risk_level: str) -> List[str]:
        """生成风险建议"""
        recommendations = []
        
        if risk_level == 'critical':
            recommendations.append('立即减仓至最小仓位')
            recommendations.append('优先处理换月操作')
            recommendations.append('密切监控市场流动性')
        elif risk_level == 'high':
            recommendations.append('大幅减仓当前合约')
            recommendations.append('加速换月进程')
            recommendations.append('使用限价单控制交易成本')
        elif risk_level == 'medium':
            recommendations.append('开始有序减仓')
            recommendations.append('评估换月时机')
            recommendations.append('关注新合约表现')
        else:
            recommendations.append('保持正常交易')
            recommendations.append('定期监控合约到期情况')
        
        return recommendations