const {
  eapiResDecrypt,
  eapiReqDecrypt,
  aesDecrypt,
  xeapiResDecrypt,
} = require('../util/crypto')
const CryptoJS = require('crypto-js')

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

module.exports = async (query, request) => {
  const crypto = query.crypto || 'eapi'
  const data = query.data || query.hexString || ''
  const isReq = query.isReq !== 'false'

  if (!data) {
    return {
      status: 400,
      body: { code: 400, message: 'data is required' },
    }
  }

  try {
    let result
    switch (crypto) {
      case 'eapi': {
        const pureHex = data.replace(/\s/g, '')
        result = isReq ? eapiReqDecrypt(pureHex) : eapiResDecrypt(pureHex)
        break
      }

      case 'weapi': {
        if (isReq) {
          return {
            status: 400,
            body: {
              code: 400,
              message:
                'weapi 请求解密需要 RSA 私钥，暂不支持；仅支持 weapi 返回数据解密（e_r=true 时与 eapi 相同）',
            },
          }
        }
        const pureHex = data.replace(/\s/g, '')
        result = eapiResDecrypt(pureHex)
        break
      }

      case 'linuxapi': {
        if (isReq) {
          const pureHex = data.replace(/\s/g, '')
          const decrypted = aesDecrypt(pureHex, linuxapiKey, '', 'hex')
          result = JSON.parse(decrypted.toString(CryptoJS.enc.Utf8))
        } else {
          result = typeof data === 'string' ? JSON.parse(data) : data
        }
        break
      }

      case 'xeapi': {
        if (isReq) {
          return {
            status: 400,
            body: {
              code: 400,
              message:
                'xeapi 请求解密涉及 X25519 ECDH 密钥交换，流程复杂，暂不支持；仅支持 xeapi 返回数据解密',
            },
          }
        }
        const buf = Buffer.from(data, 'base64')
        result = xeapiResDecrypt(buf)
        break
      }

      case 'api': {
        result = typeof data === 'string' ? JSON.parse(data) : data
        break
      }

      default:
        return {
          status: 400,
          body: { code: 400, message: `未知加密方式: ${crypto}` },
        }
    }

    return {
      status: 200,
      body: { code: 200, data: result },
    }
  } catch (error) {
    return {
      status: 400,
      body: { code: 400, message: `解密失败: ${error.message}` },
    }
  }
}