/*
 * Copyright 2021 Tianmian Tech. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.welab.wefe.common.file.decompression.impl;

import com.welab.wefe.common.file.decompression.AbstractDecompression;
import com.welab.wefe.common.file.decompression.dto.DecompressionResult;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Enumeration;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

/**
 * @author zane
 * @date 2021/11/29
 */
public class Zip extends AbstractDecompression {
    private static final int BUFFER_SIZE = 2 * 1024;

    @Override
    protected DecompressionResult doDecompression(File srcFile, String destDir) throws IOException {
        // 开始解压
        ZipFile zipFile = null;
        DecompressionResult result = new DecompressionResult(srcFile, destDir);
        try {
            zipFile = new ZipFile(srcFile);
            Enumeration<?> entries = zipFile.entries();
            while (entries.hasMoreElements()) {
                ZipEntry entry = (ZipEntry) entries.nextElement();
                // 如果是文件夹，就创建个文件夹
                if (entry.isDirectory()) {
                    String dirPath = destDir + "/" + entry.getName();
                    File dir = new File(dirPath);
                    dir.mkdirs();
                    result.addDir(dir);
                } else {
                    // 如果是文件，就先创建一个文件，然后用io流把内容copy过去
                    File targetFile = new File(destDir + "/" + entry.getName());
                    // 保证这个文件的父文件夹必须要存在
                    if (!targetFile.getParentFile().exists()) {
                        targetFile.getParentFile().mkdirs();
                    }
                    targetFile.createNewFile();
                    // 将压缩文件内容写入到这个文件中
                    InputStream is = zipFile.getInputStream(entry);
                    FileOutputStream fos = new FileOutputStream(targetFile);
                    int len;
                    byte[] buf = new byte[BUFFER_SIZE];
                    while ((len = is.read(buf)) != -1) {
                        fos.write(buf, 0, len);
                    }
                    // 关流顺序，先打开的后关闭
                    fos.close();
                    is.close();
                    result.addFile(targetFile);
                }
            }
        } finally {
            if (zipFile != null) {
                try {
                    zipFile.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        return result;
    }
}
