import cron from 'node-cron';
import nodemailer from 'nodemailer';

const transporter = nodemailer.createTransport({
        host: process.env.SMTP_HOST,
        port: parseInt(process.env.SMTP_PORT || '587'),
        secure: false,
        auth: {
            user: process.env.SMTP_USER,
            pass: process.env.SMTP_PASS,
        }
});

export async function sendReportEmail(start, end, subject = "TrACreport Summary") {
  const url = new URL(process.env.WEBURL);
  url.searchParams.set('start', start.toISOString().slice(0, 10));
  url.searchParams.set('end', end.toISOString().slice(0, 10));
  url.searchParams.set('password', process.env.PASSWORD);

  const maxAttempts = 3;
  const delay = (ms) => new Promise((res) => setTimeout(res, ms));

  for (let attempt = 1; attempt <= maxAttempts; attempt++) {
    try {
      console.log(`📡 Attempt ${attempt}: fetching ${url}`);

      const res = await fetch(url.toString());
      if (!res.ok) throw new Error(`Fetch failed: ${res.status} ${res.statusText}`);

      const html = await res.text();

      await transporter.sendMail({
        from: `"TrACreport Bot" <${process.env.SMTP_USER}>`,
        to: process.env.MAIL_RECIPIENTS,
        subject,
        html,
      });

      console.log(`✅ Report emailed: ${subject} (${start.toISOString().slice(0, 10)})`);
      return; // Success, exit function

    } catch (err) {
      console.error(`❌ Attempt ${attempt} failed:`, err);

      if (attempt < maxAttempts) {
        console.log(`⏳ Retrying in 5s...`);
        await delay(5000); // Wait before retry
      } else {
        console.error(`🚫 All ${maxAttempts} attempts failed. Giving up.`);
      }
    }
  }
}

// Daily Report
cron.schedule('5 1 * * *', () => {
  const today = new Date();
  const yesterday = new Date(today);
  yesterday.setUTCDate(today.getUTCDate() - 1);
  sendReportEmail(yesterday, yesterday, "TrACreport Daily Report");
});

// Weekly Report
cron.schedule('10 1 * * 1', () => {
    const today = new Date();
    const end = new Date(today);
    end.setUTCDate(roday.getUTCDate() - 1);
    const start = new Date(end);
    start.setUTCDate(end.getUTCDate() - 6);
    sendReportEmail(start, end, "TrACreport Weekly Report");
})

// Monthly Report
cron.schedule('15 1 1 * *', () => {
  const today = new Date();
  const end = new Date(Date.UTC(today.getUTCFullYear(), today.getUTCMonth(), 0)); // Last day of previous month
  const start = new Date(Date.UTC(end.getUTCFullYear(), end.getUTCMonth(), 1));   // First day of previous month
  sendReportEmail(start, end, "TrACreport Monthly Report");
});

console.log('📅 TrACreport schedulers are active');