import { encrypt, decrypt } from 'crypto-js/aes';
import { parse } from 'crypto-js/enc-utf8';
import pkcs7 from 'crypto-js/pad-pkcs7';
import md5 from 'crypto-js/md5';
import UTF8 from 'crypto-js/enc-utf8';
import Base64 from 'crypto-js/enc-base64';
import * as CryptoJS from 'crypto-js';

export interface EncryptionParams {
  key: string;
  iv: string;
}

export class AesEncryption {
  key;
  iv;

  constructor(opt: Partial<EncryptionParams> = {}) {
    const { key, iv } = opt;
    if (key) {
      this.key = parse(key);
    }
    if (iv) {
      this.iv = parse(iv);
    }
  }

  get getOptions() {
    return {
      mode: CryptoJS.mode.CBC,
      padding: pkcs7,
      iv: this.iv,
    };
  }

  encryptByAES(cipherText: string) {
    return encrypt(cipherText, this.key, this.getOptions).toString();
  }

  decryptByAES(cipherText: string) {
    return decrypt(cipherText, this.key, this.getOptions).toString(UTF8);
  }

  // 将 Uint8Array 转换为 CryptoJS.lib.WordArray
  static uint8ArrayToWordArray(uint8Array: Uint8Array): CryptoJS.lib.WordArray {
    const words: number[] = [];
    for (let i = 0; i < uint8Array.length; i += 4) {
      let word = 0;
      for (let j = 0; j < 4 && i + j < uint8Array.length; j++) {
        word |= (uint8Array[i + j] & 0xff) << (24 - 8 * j);
      }
      words.push(word);
    }
    return CryptoJS.lib.WordArray.create(words, uint8Array.length);
  }

  // 将 CryptoJS.lib.WordArray 转换为 Uint8Array
  static wordArrayToUint8Array(wordArray: CryptoJS.lib.WordArray): Uint8Array {
    const words = wordArray.words;
    const sigBytes = wordArray.sigBytes;
    const uint8Array = new Uint8Array(sigBytes);

    for (let i = 0; i < sigBytes; i++) {
      const byte = (words[i >>> 2] >>> (24 - (i % 4) * 8)) & 0xff;
      uint8Array[i] = byte;
    }

    return uint8Array;
  }
}

export function encryptByBase64(cipherText: string) {
  return UTF8.parse(cipherText).toString(Base64);
}

export function decodeByBase64(cipherText: string) {
  return Base64.parse(cipherText).toString(UTF8);
}

export function encryptByMd5(password: string) {
  return md5(password).toString();
}