import { Injectable } from '@angular/core';
import CryptoJS from 'crypto-js';
import crypto from 'crypto';
import moment from 'moment';

import { CipherUtil } from '../utils/CipherUtil';

@Injectable({
  providedIn: 'root'
})
export class DaesangCipherService {
  constructor() {}

  encrypt(pvUserKey: string, pvSource: string, isBase64: string): string {
    const cipherKeyDTD = CipherUtil.makeCipherKey('AES', pvUserKey);

    const cipher = crypto.createCipheriv(
      'aes-128-cbc',
      cipherKeyDTD.key,
      cipherKeyDTD.iv
    );
    cipher.setAutoPadding(true);

    let outputEncoding: 'base64' | 'hex';

    if ('Y' === isBase64) {
      outputEncoding = 'base64';
    } else {
      outputEncoding = 'hex';
    }

    const cipherChunks = [];
    cipherChunks.push(cipher.update(pvSource, 'utf8', outputEncoding));
    cipherChunks.push(cipher.final(outputEncoding));

    return cipherChunks.join('');
  }

  encryptForWebLink(pvSource: string): string {
    return CryptoJS.SHA1(pvSource)
      .toString()
      .toUpperCase();
  }

  /**
   * Sap of Weblink
   * @description
   * const enc = this.daesangCipherService.encryptForSapErp('aes256-daesang-key!!',12345678);
   * console.log('enc', enc);
   * const dec = this.daesangCipherService.decryptForSapErp('aes256-daesang-key!!',enc);
   * console.log('dec', dec);
   */
  encryptForSapErp(pvUserKey: string, employeeNum: string): string {
    // const txt = '20200221090321_asdfghjk'; // 1QgLAiLqJ6Uo6bE4Qk1o3Yd6mfqxXSnmqXX%2FXLL7DoA%3D
    // const txt = '20200221101444_asdfghjk'; // Lz1TIdGTQQMui%2BBHMdj8fatYYhXbwJEL%2BJ91C7jUWEs%3D
    const str =
      moment().format('YYYYMMDDHHmmss') + '_' + employeeNum.toUpperCase();
    const secretKeyToByteArray: Buffer = Buffer.from(pvUserKey, 'utf8').slice(
      0,
      16
    );
    const ivParamenter: Buffer = Buffer.from(pvUserKey.slice(0, 16));
    const cipher: crypto.Cipher = crypto.createCipheriv(
      'aes-128-cbc',
      secretKeyToByteArray,
      ivParamenter
    );
    let encryptedValue: string = cipher.update(str, 'utf8', 'base64');
    encryptedValue += cipher.final('base64');

    return encodeURIComponent(encryptedValue);
  }

  decryptForSapErp(pvUserKey: string, encryptedValue: string): string {
    const secretKeyToByteArray: Buffer = Buffer.from(pvUserKey, 'utf8').slice(
      0,
      16
    );
    const ivParamenter: Buffer = Buffer.from(pvUserKey.slice(0, 16));
    const cipher: crypto.Decipher = crypto.createDecipheriv(
      'aes-128-cbc',
      secretKeyToByteArray,
      ivParamenter
    );
    let decryptedValue: string = cipher.update(
      decodeURIComponent(encryptedValue),
      'base64',
      'utf8'
    );
    decryptedValue += cipher.final('utf8');

    return decryptedValue;
  }
}