package com.yang.ftpdemo.crypt;

import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.crypto.*;
import javax.crypto.spec.SecretKeySpec;
import javax.servlet.http.HttpServletResponse;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.Random;
import java.util.UUID;

@Slf4j
@RestController
@RequestMapping("/file")
public class FileController {

    /**
     * 加密接口
     *
     * @param file 文件本体
     * @return
     */
    @PostMapping("/encrypt")
    public void encrypt(@RequestParam("file") MultipartFile file) throws IOException {
        if (file.isEmpty()) {
            log.error("【保存失败！文件出错，file={}】", file);
        }
        // 文件名加上文件后缀名
        String originalName = file.getOriginalFilename();
        String suffixName = originalName.substring(originalName.lastIndexOf("."));
        String filename = UUID.randomUUID() + String.valueOf(new Random().nextInt(1000)) + suffixName;
        encrypt(file.getInputStream(), new FileOutputStream("D:\\22222222.exe"), initAESCipher("123", 1));
    }

    /**
     * 加密静态方法
     *
     * @param inputStream
     * @param outputStream
     * @param cipher
     */
    public static void encrypt(InputStream inputStream, OutputStream outputStream, Cipher cipher) {
        try {
            // 创建加密流
            CipherInputStream cipherInputStream = new CipherInputStream(inputStream, cipher);
            int isread = 0;
            byte[] cache = new byte[1024];
            // 加密流写入文件
            while ((isread = cipherInputStream.read(cache, 0, cache.length)) != -1) {
                outputStream.write(cache, 0, isread);
            }
            cipherInputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (inputStream != null) {
                    inputStream.close();
                }
                if (outputStream != null) {
                    outputStream.flush();
                    outputStream.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 解密接口
     *
     * @param response
     * @param file
     * @throws IOException
     */
    @PostMapping("/decrypt")
    public void decrypt(HttpServletResponse response, @RequestParam("file") MultipartFile file) throws IOException {
        response.setHeader("content-disposition", "attachment;filename=1333");
        decrypt(file.getInputStream(), response.getOutputStream(), initAESCipher("123", 2));
    }

    /**
     * 解密静态方法
     *
     * @param inputStream
     * @param outputStream
     * @param cipher
     */
    public static void decrypt(InputStream inputStream, OutputStream outputStream, Cipher cipher) {
        try {
            // 创建解密流
            CipherOutputStream cipherOutputStream = new CipherOutputStream(outputStream, cipher);
            int isread = 0;
            byte[] cache = new byte[1024];
            while ((isread = inputStream.read(cache, 0, cache.length)) != -1) {
                cipherOutputStream.write(cache, 0, isread);
            }
            cipherOutputStream.flush();
            cipherOutputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (inputStream != null) {
                    inputStream.close();
                }
                if (outputStream != null) {
                    outputStream.flush();
                    outputStream.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * Cipher初始化静态方法
     *
     * @param sKey
     * @param cipherMode
     * @return
     */
    public static Cipher initAESCipher(String sKey, int cipherMode) {
        Cipher cipher = null;
        KeyGenerator generator = null;
        try {
            generator = KeyGenerator.getInstance("AES");
            generator.init(128, new SecureRandom(sKey.getBytes()));

            SecretKey secretKey = generator.generateKey();
            byte[] codeFormat = secretKey.getEncoded();

            cipher = Cipher.getInstance("AES");
            SecretKeySpec keySpec = new SecretKeySpec(codeFormat, "AES");

            cipher.init(cipherMode, keySpec);
        } catch (NoSuchAlgorithmException | InvalidKeyException | NoSuchPaddingException e) {
            e.printStackTrace();
        }
        return cipher;
    }
}