import { Injectable } from "@nestjs/common";
import { ConfigService } from "@nestjs/config";
import * as nodemailer from "nodemailer";

@Injectable()
export class MailService {
  private transporter: nodemailer.Transporter;
  private mailServiceAvailable = false;

  constructor(private readonly configService: ConfigService) {
    const mailId = this.configService.get<string | undefined>("MAIL_ID");
    const mailPass = this.configService.get<string | undefined>("MAIL_PASS");

    if (!mailId || !mailPass)
      throw new Error("Make sure MAIL_ID and MAIL_PASS environment variables are set")

    // Use secure in prod
    // TODO: A table for failed emails to retry later(actually bullmq)
    this.transporter = nodemailer.createTransport({
      host: "smtp.gmail.com",
      port: 587,
      secure: false, // Use true for port 465, false for port 587
      auth: {
        user: mailId,
        pass: mailPass,
      },
      from: mailId
    });

    this.mailServiceAvailable = true;
  }

  sendMail({ to, subject, body }: { to: string, subject: string, body: string }) {
    if (!this.mailServiceAvailable)
      throw new Error("Mail service not available")

    this.transporter.sendMail(
      {
        to,
        subject,
        html: body
      }
    )
  }
}