"""
通用数据加载器
"""
import pandas as pd
import numpy as np
from pathlib import Path
from typing import Union, Dict, Any, Optional
import logging

logger = logging.getLogger(__name__)


class DataLoader:
    """通用数据加载器"""
    
    def __init__(self, data_path: Union[str, Path]):
        """初始化数据加载器"""
        self.data_path = Path(data_path)
        
    def load_csv(self, **kwargs) -> pd.DataFrame:
        """加载CSV文件"""
        try:
            df = pd.read_csv(self.data_path, **kwargs)
            logger.info(f"成功加载CSV文件: {self.data_path}")
            return df
        except Exception as e:
            logger.error(f"加载CSV文件失败: {e}")
            raise
    
    def load_json(self, **kwargs) -> pd.DataFrame:
        """加载JSON文件"""
        try:
            df = pd.read_json(self.data_path, **kwargs)
            logger.info(f"成功加载JSON文件: {self.data_path}")
            return df
        except Exception as e:
            logger.error(f"加载JSON文件失败: {e}")
            raise
    
    def load_parquet(self, **kwargs) -> pd.DataFrame:
        """加载Parquet文件"""
        try:
            df = pd.read_parquet(self.data_path, **kwargs)
            logger.info(f"成功加载Parquet文件: {self.data_path}")
            return df
        except Exception as e:
            logger.error(f"加载Parquet文件失败: {e}")
            raise
    
    def save_csv(self, df: pd.DataFrame, **kwargs) -> None:
        """保存为CSV文件"""
        try:
            df.to_csv(self.data_path, **kwargs)
            logger.info(f"成功保存CSV文件: {self.data_path}")
        except Exception as e:
            logger.error(f"保存CSV文件失败: {e}")
            raise
    
    def save_json(self, df: pd.DataFrame, **kwargs) -> None:
        """保存为JSON文件"""
        try:
            df.to_json(self.data_path, **kwargs)
            logger.info(f"成功保存JSON文件: {self.data_path}")
        except Exception as e:
            logger.error(f"保存JSON文件失败: {e}")
            raise
    
    def save_parquet(self, df: pd.DataFrame, **kwargs) -> None:
        """保存为Parquet文件"""
        try:
            df.to_parquet(self.data_path, **kwargs)
            logger.info(f"成功保存Parquet文件: {self.data_path}")
        except Exception as e:
            logger.error(f"保存Parquet文件失败: {e}")
            raise


class ImageDataLoader:
    """图像数据加载器"""
    
    def __init__(self, data_dir: Union[str, Path]):
        """初始化图像数据加载器"""
        self.data_dir = Path(data_dir)
    
    def load_images(self, extensions: list = ['.jpg', '.jpeg', '.png', '.bmp']) -> list:
        """加载图像文件路径"""
        image_paths = []
        for ext in extensions:
            image_paths.extend(self.data_dir.glob(f'**/*{ext}'))
            image_paths.extend(self.data_dir.glob(f'**/*{ext.upper()}'))
        
        logger.info(f"找到 {len(image_paths)} 个图像文件")
        return sorted(image_paths)
    
    def create_dataset_info(self, image_paths: list, label_func: callable = None) -> pd.DataFrame:
        """创建数据集信息DataFrame"""
        data = []
        for img_path in image_paths:
            if label_func:
                label = label_func(img_path)
            else:
                # 默认从文件夹名获取标签
                label = img_path.parent.name
            
            data.append({
                'image_path': str(img_path),
                'label': label,
                'filename': img_path.name
            })
        
        return pd.DataFrame(data)


class TextDataLoader:
    """文本数据加载器"""
    
    def __init__(self, data_path: Union[str, Path]):
        """初始化文本数据加载器"""
        self.data_path = Path(data_path)
    
    def load_text(self, encoding: str = 'utf-8') -> str:
        """加载文本文件"""
        try:
            with open(self.data_path, 'r', encoding=encoding) as f:
                text = f.read()
            logger.info(f"成功加载文本文件: {self.data_path}")
            return text
        except Exception as e:
            logger.error(f"加载文本文件失败: {e}")
            raise
    
    def load_lines(self, encoding: str = 'utf-8') -> list:
        """按行加载文本文件"""
        try:
            with open(self.data_path, 'r', encoding=encoding) as f:
                lines = f.readlines()
            logger.info(f"成功加载文本文件，共 {len(lines)} 行: {self.data_path}")
            return lines
        except Exception as e:
            logger.error(f"加载文本文件失败: {e}")
            raise