'use strict'

const crypto = require('crypto')
const parse = require('url').parse
const bodyify = require('querystring').stringify

const eapiKey = 'e82ckenh8dichen8'
const linuxapiKey = 'rFgB&h#%2?^eDg:Q'

const decrypt = (buffer, key) => {
  const decipher = crypto.createDecipheriv('aes-128-ecb', key, '')
  return Buffer.concat([decipher.update(buffer), decipher.final()])
}

const encrypt = (buffer, key) => {
  const cipher = crypto.createCipheriv('aes-128-ecb', key, '')
  return Buffer.concat([cipher.update(buffer), cipher.final()])
}

module.exports = {
  eapi: {
    encrypt: buffer => encrypt(buffer, eapiKey),
    decrypt: buffer => decrypt(buffer, eapiKey),
    encryptRequest: (url, object) => {
      url = parse(url)
      const text = JSON.stringify(object)
      const message = `nobody${url.path}use${text}md5forencrypt`
      const digest = crypto
        .createHash('md5')
        .update(message)
        .digest('hex')
      const data = `${url.path}-36cd479b6b5-${text}-36cd479b6b5-${digest}`
      return {
        url: url.href.replace(/\w*api/, 'eapi'),
        body: bodyify({
          params: module.exports.eapi
            .encrypt(Buffer.from(data))
            .toString('hex')
            .toUpperCase()
        })
      }
    }
  },
  linuxapi: {
    encrypt: buffer => encrypt(buffer, linuxapiKey),
    decrypt: buffer => decrypt(buffer, linuxapiKey),
    encryptRequest: (url, object) => {
      url = parse(url)
      const text = JSON.stringify({
        method: 'POST',
        url: url.href,
        params: object
      })
      return {
        url: url.resolve('/api/linux/forward'),
        body: bodyify({
          eparams: module.exports.linuxapi
            .encrypt(Buffer.from(text))
            .toString('hex')
            .toUpperCase()
        })
      }
    }
  },
  miguapi: {
    encryptBody: object => {
      const text = JSON.stringify(object)
      const derive = (password, salt, keyLength, ivSize) => {
        // EVP_BytesToKey
        salt = salt || Buffer.alloc(0)
        const keySize = keyLength / 8
        const repeat = Math.ceil((keySize + ivSize * 8) / 32)
        const buffer = Buffer.concat(
          Array(repeat)
            .fill(null)
            .reduce(
              result =>
                result.concat(
                  crypto
                    .createHash('md5')
                    .update(
                      Buffer.concat([result.slice(-1)[0], password, salt])
                    )
                    .digest()
                ),
              [Buffer.alloc(0)]
            )
        )
        return {
          key: buffer.slice(0, keySize),
          iv: buffer.slice(keySize, keySize + ivSize)
        }
      }
      const password = Buffer.from(crypto.randomBytes(32).toString('hex')),
        salt = crypto.randomBytes(8)
      const key =
        '-----BEGIN PUBLIC KEY-----\nMIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC8asrfSaoOb4je+DSmKdriQJKWVJ2oDZrs3wi5W67m3LwTB9QVR+cE3XWU21Nx+YBxS0yun8wDcjgQvYt625ZCcgin2ro/eOkNyUOTBIbuj9CvMnhUYiR61lC1f1IGbrSYYimqBVSjpifVufxtx/I3exReZosTByYp4Xwpb1+WAQIDAQAB\n-----END PUBLIC KEY-----'
      const secret = derive(password, salt, 256, 16)
      const cipher = crypto.createCipheriv('aes-256-cbc', secret.key, secret.iv)
      return bodyify({
        data: Buffer.concat([
          Buffer.from('Salted__'),
          salt,
          cipher.update(Buffer.from(text)),
          cipher.final()
        ]).toString('base64'),
        secKey: crypto
          .publicEncrypt(
            { key, padding: crypto.constants.RSA_PKCS1_PADDING },
            password
          )
          .toString('base64')
      })
    }
  },
  base64: {
    encode: (text, charset) =>
      Buffer.from(text, charset)
        .toString('base64')
        .replace(/\+/g, '-')
        .replace(/\//g, '_'),
    decode: (text, charset) =>
      Buffer.from(
        text.replace(/-/g, '+').replace(/_/g, '/'),
        'base64'
      ).toString(charset)
  },
  uri: {
    retrieve: id => {
      id = id.toString().trim()
      const key = '3go8&$8*3*3h0k(2)2'
      const string = Array.from(Array(id.length).keys())
        .map(index =>
          String.fromCharCode(
            id.charCodeAt(index) ^ key.charCodeAt(index % key.length)
          )
        )
        .join('')
      const result = crypto
        .createHash('md5')
        .update(string)
        .digest('base64')
        .replace(/\//g, '_')
        .replace(/\+/g, '-')
      return `http://p1.music.126.net/${result}/${id}`
    }
  },
  md5: {
    digest: value =>
      crypto
        .createHash('md5')
        .update(value)
        .digest('hex'),
    pipe: source =>
      new Promise((resolve, reject) => {
        const digest = crypto.createHash('md5').setEncoding('hex')
        source
          .pipe(digest)
          .on('error', error => reject(error))
          .once('finish', () => resolve(digest.read()))
      })
  }
}

try {
  module.exports.kuwoapi = require('./kwDES')
} catch (e) {}