"""
高级筛选操作

提供多条件筛选功能，支持AND/OR逻辑组合。
"""

import pandas as pd
from typing import List, Dict, Any, Literal


def apply_filter(
    df: pd.DataFrame,
    conditions: List[Dict[str, Any]],
    logic: Literal['and', 'or'] = 'and'
) -> pd.DataFrame:
    """
    应用筛选条件
    
    Args:
        df: 输入数据框
        conditions: 筛选条件列表，每个条件包含：
            - column: 列名
            - operator: 运算符 (=, !=, >, <, >=, <=, contains, not_contains, 
                       starts_with, ends_with, is_null, not_null)
            - value: 值（is_null和not_null不需要）
        logic: 逻辑组合方式 ('and' 或 'or')
    
    Returns:
        筛选后的数据框
    
    Examples:
        >>> df = pd.DataFrame({'年龄': [25, 35, 45], '性别': ['男', '女', '男']})
        >>> conditions = [
        ...     {'column': '年龄', 'operator': '>', 'value': 30},
        ...     {'column': '性别', 'operator': '=', 'value': '男'}
        ... ]
        >>> result = apply_filter(df, conditions, logic='and')
        >>> len(result)
        1
    """
    if not conditions:
        raise ValueError('筛选条件不能为空')
    
    if df.empty:
        return df
    
    # 生成各个条件的mask
    masks = []
    for cond in conditions:
        column = cond['column']
        operator = cond['operator']
        value = cond.get('value')
        
        # 验证列是否存在
        if column not in df.columns:
            raise KeyError(f"列 '{column}' 不存在")
        
        # 根据运算符生成mask
        if operator == '=':
            mask = df[column] == value
        elif operator == '!=':
            mask = df[column] != value
        elif operator == '>':
            mask = df[column] > value
        elif operator == '<':
            mask = df[column] < value
        elif operator == '>=':
            mask = df[column] >= value
        elif operator == '<=':
            mask = df[column] <= value
        elif operator == 'contains':
            mask = df[column].astype(str).str.contains(str(value), na=False)
        elif operator == 'not_contains':
            mask = ~df[column].astype(str).str.contains(str(value), na=False)
        elif operator == 'starts_with':
            mask = df[column].astype(str).str.startswith(str(value), na=False)
        elif operator == 'ends_with':
            mask = df[column].astype(str).str.endswith(str(value), na=False)
        elif operator == 'is_null':
            mask = df[column].isna()
        elif operator == 'not_null':
            mask = df[column].notna()
        else:
            raise ValueError(f"不支持的运算符: {operator}")
        
        masks.append(mask)
    
    # 组合所有条件
    if logic == 'and':
        final_mask = pd.concat(masks, axis=1).all(axis=1)
    elif logic == 'or':
        final_mask = pd.concat(masks, axis=1).any(axis=1)
    else:
        raise ValueError(f"不支持的逻辑运算: {logic}")
    
    # 应用筛选
    result = df[final_mask].copy()
    
    # 打印统计信息
    original_rows = len(df)
    filtered_rows = len(result)
    removed_rows = original_rows - filtered_rows
    
    print(f'原始数据: {original_rows} 行')
    print(f'筛选后: {filtered_rows} 行')
    print(f'删除: {removed_rows} 行 ({removed_rows/original_rows*100:.1f}%)')
    
    return result