var CryptoJS = require("crypto-js");
var fHEX = require("crypto-js/format-hex");

function enc(text, key){
    var encrypt = CryptoJS.TripleDES.encrypt(text, key, {
            mode: CryptoJS.mode.ECB,  // CBC模式
            // mode: CryptoJS.mode.ECB,  // ECB模式
            padding: CryptoJS.pad.NoPadding // padding处理
        }
    );
    var encryptData = encrypt.toString(fHEX); // 加密完成后，转换成字符串
    // console.log(encryptData)
    return encryptData

}

/**
 * int 转 byte
 * @param i
 */
function intToByte(i) {
    var b = i & 0xFF;
    var c = 0;
    if (b >= 128) {
        c = b % 128;
        c = -1 * (128 - c);
    } else {
        c = b;
    }
    return c;
}

function stringToHex(str){
    var val = "";
    for (var i = 0; i < str.length; i++) {
        var v = str.charCodeAt(i).toString(16);
        if ( v.length < 2 ) {
            v = "0" + v;
        }
        val += v;
    }
    return val
}
function toHex(d) { return ("0"+(Number(d).toString(16))).slice(-2).toUpperCase() }

function mac( hex ) {
    if ( ! /^([A-Fa-f0-9][A-Fa-f0-9])+$/.test( hex ) ) {
        throw "hex 格式错误"
    }
    var checkNum = intToByte(0);
    var arrBytes = new Array();
    for ( var i = 0 ; i < hex.length; i+=2 ) {
        var v = intToByte(parseInt(hex[i] + hex[i+1], 16))
        arrBytes.push( v )
        checkNum = checkNum ^ v;
    }

    return toHex( checkNum & 0xFF )
}

function xor(d1, d2, d3) {
    if ( 32 !== d1.length || 32 !== d2.length || 32 !== d3.length ) {
        throw "输入格式错误"
    }

    var a1 = hexToBytes(d1);
    var a2 = hexToBytes(d2);
    var a3 = hexToBytes(d3);

    var data = [];
    for ( var i = 0; i < 16 ; i++){
        data[ i ] = a1[ i ] ^ a2[ i ] ^ a3[ i ]
    }

    return bytesToHex( data )
}

// Des3
// npm i crypto-js
function hexToBytes(hex) {
    for (var bytes = [], c = 0; c < hex.length; c += 2)
        bytes.push(parseInt(hex.substr(c, 2), 16));
    return bytes;
}

function bytesToHex(bytes) {
    for (var hex = [], i = 0; i < bytes.length; i++) {
        hex.push((bytes[i] >>> 4).toString(16));
        hex.push((bytes[i] & 0xF).toString(16));
    }
    return hex.join("");
}

const des = {
    CalDES: function (a1, a2) {
        a1 = "00000000000000000000000000000000"
        a2 = bytesToHex(a2)
        //  var data = [];
        // for ( var i = 0; i < 16 ; i++){
        //     data[ i ] = a1[ i ] ^ a2[ i ]
        // }

        // return bytesToHex( data )

        var text = CryptoJS.enc.Hex.parse(a1);
        var key = CryptoJS.enc.Hex.parse(a2);
        return enc(text, key);

    }
}

const sm4 = require('./sm4.js')


// 校验值
function checkValue(p1,p2,p3) {
    var keyPlaintext = xor(p1, p2, p3)
    // 废弃 des 算法
    // var ret = des.CalDES(hexToBytes("0000000000000000"), hexToBytes(keyPlaintext))
    var ret = sm4.SM4CryptECB("00000000000000000000000000000000", 1, keyPlaintext)
    const checkValue = ret.slice(0, 8)
    return { checkValue, ret, keyPlaintext }
}

// 校验值
function checkValueKey(l1,l2,l3, protectKey) {
    const key = xor(l1,l2,l3)
    var ret = sm4.SM4CryptECB("00000000000000000000000000000000", 1, key)
    const checkValue = ret.slice(0, 8)
    const keyCiphertext = sm4.SM4CryptECB(key, 1 , protectKey)
    return { keyCiphertext, checkValue, ret}
}

function decryptionKey(keyCiphertext, checkValue) {
    const keyPlaintext = sm4.SM4CryptECB(keyCiphertext, 0, checkValue)
    let ret = kcv( keyCiphertext )
    const checkData = ret.slice(0, 8)
    return { keyPlaintext, checkData }
}

/**
 * 计算密钥校验值
 * key 是密钥 16 字节的 HEX 格式。
 */
function kcv( key ){
  const v = sm4.SM4CryptECB("00000000000000000000000000000000", 1, key)
  return v;
}

function decryptKey(value, key){
  const v = sm4.SM4CryptECB(value, 0, key)
  return v;
}

module.exports = { xor, kcv, decryptKey, checkValue, checkValueKey, decryptionKey }

// const tripledes = require("crypto-js/tripledes");
//
// var value = "123";CryptoJS.enc.Hex.parse("0000000000000000");
// var key = "12345678123456781234567812345678"; CryptoJS.enc.Hex.parse("12345678123456781234567812345678");
//
// var encrypted = tripledes.encrypt(value , key);
// var decrypted = tripledes.decrypt(encrypted, key);
//
// console.log( "encrypted", encrypted.toString('hex') )
// console.log( "decrypted", decrypted )