/**
 * 邮件收发管理
 * @author yutent<yutent.io@gmail.com>
 * @date 2020/09/18 15:59:31
 */

import nodemailer from 'nodemailer'

const DEFAULT_CONFIG = {
  host: 'smtp.example.com',
  port: 465,
  secure: true,
  auth: {
    user: 'no-reply@example.com',
    username: 'no-reply',
    pass: ''
  }
}

export class Mailer {
  #smtp = null

  #from = ''
  #to = ''

  constructor(opts) {
    this.#smtp = nodemailer.createTransport(opts)
    this.#from = `${opts.auth.username || 'no named'}"<${opts.auth.user}>"`
  }

  // 发件人
  from(email, username) {
    this.#from = `${username || 'no named'}"<${email}>"`
    return this
  }

  // 收件人
  to(email, username) {
    this.#to = `${username || 'no named'}"<${email}>"`
    return this
  }

  // 发送正文
  send(
    mail = {
      subject: 'example mail',
      text: 'example mail plain content',
      html: '<p>example mail html content</p>'
    }
  ) {
    if (!this.#to) {
      throw new Error('the email address send to is empty!')
    }

    mail.from = this.#from
    mail.to = this.#to

    this.#to = ''

    return this.#smtp.sendMail(mail)
  }
}

export const MailModule = {
  name: 'mail',
  install(conf = {}) {
    if (!conf.auth) {
      throw new Error('mail auth account must not be empty.')
    }

    let smtp = Object.assign({}, DEFAULT_CONFIG, conf)

    return new Mailer(smtp)
  }
}