"""
因子有效性检验模块：整合所有检验方案
"""
import numpy as np
import pandas as pd
from typing import Dict, List, Optional
from dataclasses import dataclass
from statsmodels.regression.linear_model import OLS

from validation import (
    compute_ic,
    compute_rolling_ic,
    group_backtest,
    factor_span_regression
)


@dataclass
class ValidationConfig:
    """验证配置"""
    ic_window: int = 30
    ic_method: str = "spearman"  # "spearman" or "pearson"
    n_groups: int = 3
    group_period: int = 180
    min_ic: float = 0.01
    min_tstat: float = 1.5
    min_r2_change: float = 0.05


class FactorValidator:
    """因子有效性检验器"""
    
    def __init__(self, config: ValidationConfig):
        self.config = config
    
    def validate_ic(
        self,
        factor: pd.Series,
        forward_return: pd.Series
    ) -> Dict:
        """
        IC检验
        
        Returns:
        --------
        dict: 包含mean_ic, ic_ir, ic_series等
        """
        rolling_ic = compute_rolling_ic(
            factor,
            forward_return,
            window=self.config.ic_window,
            method=self.config.ic_method
        )
        
        mean_ic = rolling_ic.mean()
        ic_std = rolling_ic.std()
        ic_ir = mean_ic / (ic_std + 1e-8)  # IC信息比率
        
        return {
            "mean_ic": mean_ic,
            "ic_std": ic_std,
            "ic_ir": ic_ir,
            "ic_series": rolling_ic,
            "is_valid": abs(mean_ic) >= self.config.min_ic
        }
    
    def validate_group_backtest(
        self,
        factor: pd.Series,
        forward_return: pd.Series
    ) -> Dict:
        """
        分组回测检验
        
        Returns:
        --------
        dict: 包含mean_h_l_return, mean_h_l_tstat等
        """
        result = group_backtest(
            factor,
            forward_return,
            n_groups=self.config.n_groups,
            group_period=self.config.group_period
        )
        
        is_valid = abs(result.get('mean_h_l_tstat', 0)) >= self.config.min_tstat
        
        return {
            **result,
            "is_valid": is_valid
        }
    
    def validate_regression(
        self,
        factor: pd.Series,
        forward_return: pd.Series,
        other_factors: Optional[pd.DataFrame] = None
    ) -> Dict:
        """
        因子跨度回归检验
        
        Parameters:
        -----------
        factor : Series
            待检验因子
        forward_return : Series
            未来收益率
        other_factors : DataFrame, optional
            其他因子（用于控制变量）
        
        Returns:
        --------
        dict: 包含beta, tstat, r2_change等
        """
        if other_factors is None:
            other_factors = pd.DataFrame()
        
        # 合并因子
        factors_df = pd.concat([other_factors, factor.to_frame(name='target')], axis=1)
        
        result = factor_span_regression(
            factors_df,
            forward_return,
            target_factor='target'
        )
        
        is_valid = (
            abs(result.get('tstat', 0)) >= self.config.min_tstat and
            result.get('r2_change', 0) >= self.config.min_r2_change
        )
        
        return {
            **result,
            "is_valid": is_valid
        }
    
    def validate_all(
        self,
        factor: pd.Series,
        forward_return: pd.Series,
        other_factors: Optional[pd.DataFrame] = None
    ) -> Dict:
        """
        综合检验：执行所有检验方法
        
        Returns:
        --------
        dict: 包含所有检验结果和综合判断
        """
        results = {}
        
        # IC检验
        ic_result = self.validate_ic(factor, forward_return)
        results['ic'] = ic_result
        
        # 分组回测
        group_result = self.validate_group_backtest(factor, forward_return)
        results['group_backtest'] = group_result
        
        # 回归检验
        reg_result = self.validate_regression(factor, forward_return, other_factors)
        results['regression'] = reg_result
        
        # 综合判断
        is_valid = (
            ic_result['is_valid'] and
            group_result['is_valid'] and
            reg_result['is_valid']
        )
        
        results['is_valid'] = is_valid
        results['score'] = self._calculate_score(ic_result, group_result, reg_result)
        
        return results
    
    def _calculate_score(
        self,
        ic_result: Dict,
        group_result: Dict,
        reg_result: Dict
    ) -> float:
        """计算综合得分"""
        score = 0.0
        
        # IC得分（权重0.3）
        ic_score = abs(ic_result.get('mean_ic', 0)) * 10
        score += ic_score * 0.3
        
        # 分组回测得分（权重0.4）
        tstat = abs(group_result.get('mean_h_l_tstat', 0))
        tstat_score = min(tstat / 3.0, 1.0)  # 归一化到[0, 1]
        score += tstat_score * 0.4
        
        # 回归得分（权重0.3）
        r2_change = reg_result.get('r2_change', 0)
        r2_score = min(r2_change / 0.1, 1.0)  # 归一化到[0, 1]
        score += r2_score * 0.3
        
        return score
    
    def filter_factors(
        self,
        factors: pd.DataFrame,
        forward_return: pd.Series
    ) -> pd.DataFrame:
        """
        批量过滤因子：只保留有效因子
        
        Returns:
        --------
        DataFrame: 有效因子
        """
        valid_factors = []
        
        for col in factors.columns:
            factor = factors[col]
            result = self.validate_all(factor, forward_return, factors.drop(columns=[col]))
            
            if result['is_valid']:
                valid_factors.append(col)
        
        return factors[valid_factors] if valid_factors else pd.DataFrame()


def create_validator(
    ic_window: int = 30,
    min_ic: float = 0.01,
    min_tstat: float = 1.5
) -> FactorValidator:
    """创建验证器（便捷函数）"""
    config = ValidationConfig(
        ic_window=ic_window,
        min_ic=min_ic,
        min_tstat=min_tstat
    )
    return FactorValidator(config)