import os
import zipfile
import py7zr
import shutil
from config import Config
from logger import logger

class ZipHandler:
    @staticmethod
    def extract_zip(zip_path, extract_to):
        """解压ZIP文件"""
        with zipfile.ZipFile(zip_path, 'r') as zf:
            zf.extractall(extract_to)
        logger.info(f"解压ZIP: {zip_path} -> {extract_to}")

    @staticmethod
    def extract_7z(seven_z_path, extract_to):
        """解压7z文件"""
        with py7zr.SevenZipFile(seven_z_path, mode='r') as sz:
            sz.extractall(extract_to)
        logger.info(f"解压7z: {seven_z_path} -> {extract_to}")

    @staticmethod
    def pack_to_zip(source_dir_or_file, output_zip_path):
        """将文件或目录打包为ZIP"""
        with zipfile.ZipFile(output_zip_path, 'w', zipfile.ZIP_DEFLATED) as zf:
            if os.path.isfile(source_dir_or_file):
                zf.write(source_dir_or_file, arcname=os.path.basename(source_dir_or_file))
            else:
                for root, _, files in os.walk(source_dir_or_file):
                    for file in files:
                        full_path = os.path.join(root, file)
                        arcname = os.path.relpath(full_path, start=os.path.dirname(source_dir_or_file))
                        zf.write(full_path, arcname)
        logger.info(f"打包为ZIP: {output_zip_path}")

    @staticmethod
    def split_zip(zip_path, volume_size_mb):
        """将ZIP文件分卷（简单实现：使用split命令或手动分割）
           由于Python标准库不支持直接生成多卷ZIP，这里采用事后分割：
           生成一个大ZIP，然后按字节分割成 .zip.001, .zip.002 ...
           注意：解压时需要合并 cat file.zip.* > file.zip 或使用专用工具。
        """
        if volume_size_mb <= 0:
            return [zip_path]
        volume_size = volume_size_mb * 1024 * 1024
        file_size = os.path.getsize(zip_path)
        if file_size <= volume_size:
            return [zip_path]
        base_name = zip_path
        part_num = 1
        parts = []
        with open(zip_path, 'rb') as f:
            while True:
                chunk = f.read(volume_size)
                if not chunk:
                    break
                part_path = f"{base_name}.{part_num:03d}"
                with open(part_path, 'wb') as pf:
                    pf.write(chunk)
                parts.append(part_path)
                part_num += 1
        # 删除原ZIP
        os.remove(zip_path)
        logger.info(f"分卷压缩完成: {parts}")
        return parts

    @staticmethod
    def is_archive(file_path):
        ext = os.path.splitext(file_path)[1].lower()
        return ext in ['.zip', '.7z']