package com.product.file.util;

import com.google.common.collect.Maps;
import com.product.common.lang.StringUtils;
import com.product.core.exception.BaseException;
import com.product.file.config.CmnConst;
import com.product.file.config.FileCode;
import org.apache.log4j.Logger;

import java.io.*;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

/**
 * Copyright © 6c
 *
 * @Date: 2021-03-05 10:59
 * @Author: 6c
 * @Description:
 */
public class FileUtil {
    private static Logger logger = Logger.getLogger(FileUtil.class);
    private static Properties properties;



    private FileUtil() {
    }


    /**
     * 批量打包
     *
     * @param pathList 文件路径集合
     * @param os       输出流
     * @return zip文件保存绝对路径
     */
    public static long createZip(List<Map<String, String>> pathList, OutputStream os) {
        logger.info("正在打包文件...");
        try {
            long size = 0;
            ZipOutputStream out = new ZipOutputStream(os);

            String downloadPath;
            int symbol;
            Map<String, Integer> fileNameCountMap = Maps.newHashMap();
            int showCount = 0;
            String fileName;
            String head;
            String tail;
            for (Map<String, String> pathMap : pathList) {
                downloadPath = pathMap.get(CmnConst.SOURCE_PATH);
                symbol = "1".equals(pathMap.get(CmnConst.ENCRPT_SIGN)) ? -1 : 0;

                //获得文件名
                fileName = pathMap.get(CmnConst.REAL_FILE_NAME);
                head = fileName.substring(0, fileName.lastIndexOf("."));
                tail = fileName.substring(fileName.lastIndexOf(".") + 1);
                showCount = fileNameCountMap.get(fileName) == null ? 0 : fileNameCountMap.get(fileName);
                if (showCount > 0) {
                    fileName = head + "(" + showCount + ")." + tail;
                }
                fileNameCountMap.put(fileName, ++showCount);
                logger.info(String.format("正在打包文件 %s", fileName));

                //以论文标题为每个文件命名
                FileInputStream fis = new FileInputStream(downloadPath);
                out.putNextEntry(new ZipEntry(fileName));

                //写入压缩包
                int len;
                byte[] buffer = new byte[1024];
                while ((len = fis.read(buffer)) > 0) {
                    if (symbol == 1) {
                        // 加密
                        logger.info("正在加密...");
                        out.write(encryption(buffer), 0, len);
                    } else if (symbol == -1) {
                        // 解密
                        logger.info("正在解密...");
                        out.write(decryption(buffer), 0, len);
                    } else {
                        // 单纯的复制
                        out.write(buffer, 0, len);
                    }
                    size += len;
                }
                out.closeEntry();
                fis.close();
            }
            out.close();
            out.flush();
            return size;
        } catch (Exception e) {
            throw new BaseException(FileCode.LOAD_FTP_PROPERTIES_FAIL.getValue(), FileCode.LOAD_FTP_PROPERTIES_FAIL.getText(), e);
        }
    }

    /**
     * 拷贝文件
     *
     * @param sourceFile
     * @param aimPath
     * @param symbol     1：加密，-1：解密，0：不动
     */
    public static File copyFile(File sourceFile, String aimPath, int symbol) {
        if (StringUtils.isEmpty(aimPath)) {
            throw new BaseException(FileCode.INVALID_FILE_PATH.getValue(), FileCode.INVALID_FILE_PATH.getText());
        }
        File aimFile = new File(aimPath);
        File aimDir = aimFile.getParentFile();
        if (!aimDir.exists()) {
            aimDir.mkdirs();
        }
        try (InputStream is = new FileInputStream(sourceFile);
             OutputStream os = new FileOutputStream(aimFile);) {
            int len;
            byte[] b = new byte[1024];
            while ((len = is.read(b)) > 0) {
                if (symbol == 1) {
                    // 加密
                    os.write(encryption(b), 0, len);
                } else if (symbol == -1) {
                    // 解密
                    os.write(decryption(b), 0, len);
                } else {
                    // 单纯的复制
                    os.write(b, 0, len);
                }
            }
            os.flush();
            return aimFile;
        } catch (IOException e) {
            throw new BaseException(FileCode.COPY_FILE_FAIL.getValue(), FileCode.COPY_FILE_FAIL.getText(), e);
        }
    }

    public static void copyFile(File sourceFile, String aimPath) {
        copyFile(sourceFile, aimPath, 0);
    }

    /**
     * 加密
     *
     * @param bytes
     * @return
     */
    public static byte[] encryption(byte[] bytes) {
        /**
         * 设置一个加密算法，要求可逆，还可以通过解密得到原来的东西
         * 我们这样做：每一个字节的值，都加上它的索引号
         * 然后，交换第一个字节和最后一个字节的位置，即加密结束
         */
        for (int i = 0; i < bytes.length; i++) {
            bytes[i] = (byte) (bytes[i] + i);
        }
        byte temp = bytes[0];
        bytes[0] = bytes[bytes.length - 1];
        bytes[bytes.length - 1] = temp;
        return bytes;

    }

    /**
     * 解密
     *
     * @param bytes
     * @return
     */
    public static byte[] decryption(byte[] bytes) {
        /**
         * 解密算法，是加密的逆过程
         * 先交换第一个字节和最后一个字节的位置
         * 然后，每一个字节的值，都减去它的索引号
         */
        byte temp = bytes[0];
        bytes[0] = bytes[bytes.length - 1];
        bytes[bytes.length - 1] = temp;
        for (int i = 0; i < bytes.length; i++) {
            bytes[i] = (byte) (bytes[i] - i);
        }
        return bytes;
    }
}