import { Transporter, createTransport, TransportOptions } from "nodemailer";
import { Attachment } from "nodemailer/lib/mailer";
import SettingHelper from "./settingsHelper";
import emailCheck from "email-check";

export default abstract class MailHelper {
  private static transporter: Transporter;

  static createTransport() {
    this.transporter?.close();

    this.transporter = createTransport({
      host: SettingHelper.getSetting("mail.host"),
      port: SettingHelper.getSetting("mail.port"),
      secure: SettingHelper.getSetting("mail.secure"),
      auth: {
        user: SettingHelper.getSetting("mail.username"),
        pass: SettingHelper.getSetting("mail.password"),
      },
    } as TransportOptions);
  }

  static async verifyTransport({
    host,
    port,
    secure,
    user,
    password,
  }: {
    host: string;
    port: number;
    secure: boolean;
    user: string;
    password: string;
  }): Promise<boolean> {
    let transport = createTransport({
      host,
      port,
      secure,
      auth: { user, pass: password },
    });

    return await transport
      .verify()
      .then(() => {
        return true;
      })
      .catch(() => {
        return false;
      })
      .finally(() => {
        try {
          transport?.close();
        } catch (error) {}
      });
  }

  static async checkMail(mail: string): Promise<boolean> {
    return await emailCheck(mail)
      .then((res) => {
        return res;
      })
      .catch((err) => {
        return false;
      });
  }

  static initialize() {
    SettingHelper.onSettingTopicChanged("mail", () => {
      this.createTransport();
    });
    this.createTransport();
  }

  /**
   * @description send mail
   * @param {string} target
   * @param {string} subject
   * @param {string} content
   * @returns {Prmose<*>}
   */
  static async sendMail(
    target: string,
    subject: string,
    content: string,
    attach: Array<Attachment> = []
  ): Promise<any> {
    return new Promise((resolve, reject) => {
      this.transporter
        .sendMail({
          from: `"${SettingHelper.getSetting("club.name")}" <${SettingHelper.getSetting("mail.email")}>`,
          to: target,
          subject,
          text: content,
          html: content,
          attachments: attach,
        })
        .then((info) => resolve(info.messageId))
        .catch((e) => reject(e));
    });
  }
}