mailer.js

const nodemailer = require("nodemailer");
const { google } = require("googleapis");
const fs = require("fs");
const path = require("path");
const { authorize, saveToken } = require("./oauth");

// Load custom variables from environment
const EMAIL = "iitd.sujas@gmail.com"; // Replace with your email

// Load credentials and token
let credentials, token;
try {
  credentials = JSON.parse(fs.readFileSync("client.json"));
  token = {};
  try {
    token = JSON.parse(fs.readFileSync("token.json"));
  } catch (e) {
    console.log("Token not found");
    // Load client secrets from a local file.
    fs.readFile("client.json", (err, content) => {
      if (err) return console.log("Error loading client secret file:", err);
      authorize(JSON.parse(content), saveToken);
    });
  }
  console.log("Credentials and token loaded successfully"); // Debug log
} catch (error) {
  console.error("Error loading credentials or token:", error);
  process.exit(1);
}

const { client_secret, client_id, redirect_uris } = credentials.installed;
const { refresh_token } = token;

// Create an OAuth2 client
const oauth2Client = new google.auth.OAuth2(
  client_id,
  client_secret,
  redirect_uris[0]
);

oauth2Client.setCredentials({ refresh_token });

// Load recipients
let mail;
try {
  mail = JSON.parse(
    fs.readFileSync(path.resolve(__dirname, "recipients.json"))
  );
  console.log("Recipients loaded:", mail); // Debug log
} catch (error) {
  console.error("Error loading recipients:", error);
  process.exit(1);
}

async function mailSender() {
  try {
    const targetEmails = mail.recievers || []; // Note: 'recievers' is misspelled
    console.log("Target emails:", targetEmails); // Debug log
    let successCount = 0;
    let failureCount = 0;

    // Get access token
    console.log("Getting access token..."); // Debug log
    const accessTokenResponse = await oauth2Client.getAccessToken();
    const accessToken = accessTokenResponse.token;
    console.log("Access token obtained"); // Debug log

    // Create reusable transporter object using OAuth2
    const transporter = nodemailer.createTransport({
      service: "gmail",
      auth: {
        type: "OAuth2",
        user: EMAIL,
        clientId: client_id,
        clientSecret: client_secret,
        refreshToken: refresh_token,
        accessToken: accessToken,
      },
    });

    // Iterate through target emails and send emails
    for (const target of targetEmails) {
      if (!target) {
        console.log("Skipping empty target"); // Debug log
        continue;
      }
      try {
        console.log(`Attempting to send email to ${target.email}`); // Debug log
        await transporter.sendMail({
          from: `${mail.name} <${mail.email || EMAIL}>`,
          to: target.email,
          subject: mail.subject.replace("${name}", target.name),
          text: "",
          html:
            mail.body.replace("${name}", target.name) ||
            "Please Ignore This Email",
        });
        successCount++;
        console.log(`Email sent successfully to ${target.email}`);
      } catch (err) {
        console.error(`Failed to send email to ${target.email}`, err);
        failureCount++;
      }
    }

    console.log(
      `Emails sent: ${successCount}, Failed attempts: ${failureCount}`
    );
  } catch (err) {
    console.error("Error in mailSender function:", err);
  }
}

module.exports = mailSender;