package com.hdl.photovoltaic.utils;

import android.annotation.SuppressLint;
import android.text.TextUtils;

import com.hdl.sdk.link.common.utils.LogUtils;

import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

import io.dcloud.common.adapter.util.CryptoProvider;

/**
 * AES加密解密
 */
public class AesUtils {

    private static final String SHA1PRNG = "HDLRDCENTER1985.";   // SHA1PRNG 强随机种子算法
    private static final String AES = "AES";   //AES 加密
    private static final String CIPHERMODE = "AES/CBC/PKCS7Padding"; //AES算法/CBC模式/PKCS5Padding填充模式

    /**
     * 解密
     *
     * @param contentByte 待解密待字符串hexStr
     * @return 解密后byte[]数组
     */
    public static byte[] decrypt(byte[] contentByte) {
        try {
            //KEY转换
            Key key = new SecretKeySpec(SHA1PRNG.getBytes(), AES);
            //解密
            Cipher cipher = Cipher.getInstance(CIPHERMODE);
            IvParameterSpec ivps = new IvParameterSpec(SHA1PRNG.getBytes());
            cipher.init(Cipher.DECRYPT_MODE, key, ivps);
            return cipher.doFinal(contentByte);
        } catch (NoSuchAlgorithmException
                 | InvalidKeyException
                 | NoSuchPaddingException
                 | BadPaddingException
                 | IllegalBlockSizeException
                 | InvalidAlgorithmParameterException e) {
            LogUtils.e(e.getMessage());
        }
        return null;
    }


    /**
     * 加密
     */
    public static String encrypt(String key, String cleartext) {
        if (TextUtils.isEmpty(cleartext)) {
            return cleartext;
        }
        try {
            byte[] result = encrypt(key, cleartext.getBytes());
            return parseByte2HexStr(result);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 加密
     */
    public static byte[] encrypt(String key, byte[] clear) throws Exception {
        byte[] raw = getRawKey(key.getBytes());
        SecretKeySpec keySpec = new SecretKeySpec(raw, AES);
        Cipher cipher = Cipher.getInstance(CIPHERMODE);
        cipher.init(Cipher.ENCRYPT_MODE, keySpec, new IvParameterSpec(new
                byte[cipher.getBlockSize()]));
        return cipher.doFinal(clear);
    }

    /**
     * 解密
     */
    public static String decrypt(String key, String encrypted) {
        if (TextUtils.isEmpty(encrypted)) {
            return encrypted;
        }
        try {
            byte[] enc = parseHexStr2Byte(encrypted);
            byte[] result = decrypt(key, enc);
            return new String(result);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 解密
     */
    public static byte[] decrypt(String key, byte[] encrypted) throws Exception {
        byte[] raw = getRawKey(key.getBytes());
        SecretKeySpec keySpec = new SecretKeySpec(raw, AES);
        Cipher cipher = Cipher.getInstance(CIPHERMODE);
        cipher.init(Cipher.DECRYPT_MODE, keySpec, new IvParameterSpec(new
                byte[cipher.getBlockSize()]));
        return cipher.doFinal(encrypted);
    }


    /**
     * 处理密钥
     */
    @SuppressLint("DeletedProvider")
    public static byte[] getRawKey(byte[] seed) throws Exception {
        KeyGenerator kgen = KeyGenerator.getInstance(AES);
        //for android
        SecureRandom sr = null;
        // 在4.2以上版本中，SecureRandom获取方式发生了改变
        if (android.os.Build.VERSION.SDK_INT >= 17) {
            sr = SecureRandom.getInstance(SHA1PRNG, new CryptoProvider());
        } else {
            sr = SecureRandom.getInstance(SHA1PRNG);
        }

        sr.setSeed(seed);
        kgen.init(128, sr); //128bits,192bits,256bits
        //AES中128位密钥，加密轮次为10轮；192位密钥，加密轮次为12轮；256位密钥，加密轮次为14轮。
        SecretKey secretKey = kgen.generateKey();
        return secretKey.getEncoded();
    }


    /**
     * 将二进制转换成16进制
     */
    public static String parseByte2HexStr(byte[] buf) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < buf.length; i++) {
            String hex = Integer.toHexString(buf[i] & 0xFF);
            if (hex.length() == 1) {
                hex = '0' + hex;
            }
            sb.append(hex.toUpperCase());
        }
        return sb.toString();
    }

    /**
     * 将16进制转换为二进制
     */
    public static byte[] parseHexStr2Byte(String hexStr) {
        if (hexStr.length() < 1)
            return null;
        byte[] result = new byte[hexStr.length() / 2];
        for (int i = 0; i < hexStr.length() / 2; i++) {
            int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
            int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2),
                    16);
            result[i] = (byte) (high * 16 + low);
        }
        return result;
    }


}