const Dm20151123 = require('@alicloud/dm20151123')
const OpenApi = require('@alicloud/openapi-client')
const TeaUtil = require('@alicloud/tea-util')

let client = null

function createClient() {
  if (client) return client

  const config = new OpenApi.Config({
    accessKeyId: process.env.ALIYUN_ACCESS_KEY_ID,
    accessKeySecret: process.env.ALIYUN_ACCESS_KEY_SECRET,
  })
  config.endpoint = process.env.ALIYUN_DM_ENDPOINT || 'dm.aliyuncs.com'
  client = new Dm20151123.default(config)
  return client
}

async function sendEmailCode(toAddress, code) {
  try {
    console.log('[Email] Sending code to:', toAddress)
    console.log('[Email] Using template ID:', process.env.ALIYUN_DM_TEMPLATE_ID)
    console.log('[Email] Using account name:', process.env.ALIYUN_DM_ACCOUNT_NAME)
    
    const dmClient = createClient()

    const template = new Dm20151123.SingleSendMailRequestTemplate({
      templateData: { code },
      templateId: process.env.ALIYUN_DM_TEMPLATE_ID,
    })

    const request = new Dm20151123.SingleSendMailRequest({
      template,
      accountName: process.env.ALIYUN_DM_ACCOUNT_NAME,
      addressType: 1,
      replyToAddress: false,
      toAddress,
      subject: process.env.ALIYUN_DM_DEFAULT_SUBJECT || '登录验证码',
    })

    console.log('[Email] Request prepared:', JSON.stringify(request, null, 2))
    
    const runtime = new TeaUtil.RuntimeOptions({})
    await dmClient.singleSendMailWithOptions(request, runtime)

    console.log('[Email] Send success')
    return { success: true }
  } catch (error) {
    const message = error.message || String(error)
    console.error('[Email] Send error:', message)
    console.error('[Email] Error details:', error)
    return { success: false, message }
  }
}

module.exports = { sendEmailCode }