package com.lxzn.framework.utils;

import net.lingala.zip4j.core.ZipFile;
import net.lingala.zip4j.io.ZipInputStream;
import net.lingala.zip4j.model.FileHeader;

import java.io.File;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @Description:
 * @Author: zhangherong
 * @Date: Created in 2021/1/29 15:24
 * @Version: 1.0
 * @Modified By:
 */
public class ZipUtil {


    /**
     * 读取压缩文件下的所有文件的文件流
     * @param file
     * @return
     * @throws Exception
     */
    public static Map<String, ZipInputStream> readZipFileStream(File file) throws Exception {
        ZipFile zipFile = new ZipFile(file);
        zipFile.setFileNameCharset(getEncoding(file));
        if(!zipFile.isValidZipFile())
            return null;
        List<FileHeader> list = zipFile.getFileHeaders();
        if(list == null || list.isEmpty())
            return null;
        Map<String, ZipInputStream> map = new HashMap<>();
        for(FileHeader fileHeader : list) {
            if(!fileHeader.isDirectory()) {
                ZipInputStream zis = zipFile.getInputStream(fileHeader);
                String fileName = fileHeader.getFileName();
                int index = fileName.lastIndexOf("/");
                if(index == -1) {
                    index = fileName.lastIndexOf("\\\\");
                    if(index == -1) {
                        index = fileName.lastIndexOf("\\");
                    }
                }
                if(index != -1) {
                    fileName = fileName.substring(index + 1);
                }
                map.put(fileName, zis);
            }
        }
        return map;
    }

    /**
     * 判断该使用哪种编码方式解压
     * @param path
     * @return
     * @throws Exception
     */
    private static String getEncoding(File path) throws Exception {
        String encoding = "GBK";
        ZipFile zipFile = new ZipFile(path);
        zipFile.setFileNameCharset(encoding);
        List<FileHeader> list = zipFile.getFileHeaders();
        for (int i = 0; i < list.size(); i++) {
            FileHeader fileHeader = list.get(i);
            String fileName = fileHeader.getFileName();
            if (isMessyCode(fileName)) {
                encoding = "UTF-8";
                break;
            }
        }
        return encoding;
    }

    private static boolean isMessyCode(String str) {
        for (int i = 0; i < str.length(); i++) {
            char c = str.charAt(i);
            // 当从Unicode编码向某个字符集转换时，如果在该字符集中没有对应的编码，则得到0x3f（即问号字符?）
            // 从其他字符集向Unicode编码转换时，如果这个二进制数在该字符集中没有标识任何的字符，则得到的结果是0xfffd
            if ((int) c == 0xfffd) {
                // 存在乱码
                return true;
            }
        }
        return false;
    }

    public static void main(String[] args) throws Exception {
        String f = "D://中国.zip";
        File file = new File(f);
        Map<String, ZipInputStream> map = readZipFileStream(file);
        if(map != null && !map.isEmpty()){
            System.out.println(map.size());
            for(Map.Entry<String, ZipInputStream> entry : map.entrySet()) {
                System.out.println(entry.getKey());
                //entry.getValue().close();
            }
        }
    }
}