import dotenv from 'dotenv';
import nodemailer from 'nodemailer';
import path from 'path';

// Load environment variables from .env
dotenv.config({ path: path.resolve(__dirname, '../.env') });

async function main() {
  const host = process.env.SMTP_HOST || 'localhost';
  const port = parseInt(process.env.SMTP_PORT || '587', 10);
  const user = process.env.SMTP_USER || '';
  const pass = process.env.SMTP_PASS || '';
  const from = process.env.SMTP_FROM || user;
  const enableReal = process.env.ENABLE_REAL_EMAILS;
  const nodeEnv = process.env.NODE_ENV;

  console.log('==================================================');
  console.log('          SMTP CREDENTIALS & SERVICE TEST         ');
  console.log('==================================================');
  console.log(`• NODE_ENV           : ${nodeEnv || '(not set)'}`);
  console.log(`• ENABLE_REAL_EMAILS : ${enableReal || '(not set)'}`);
  console.log(`• SMTP_HOST          : ${host}`);
  console.log(`• SMTP_PORT          : ${port}`);
  console.log(`• SMTP_USER          : ${user || '(empty)'}`);
  console.log(`• SMTP_PASS          : ${pass ? '********' : '(empty)'}`);
  console.log(`• SMTP_FROM          : ${from}`);
  console.log('--------------------------------------------------');

  if (enableReal !== 'true') {
    console.warn('⚠️ WARNING: ENABLE_REAL_EMAILS is not set to "true". Real email dispatch is disabled in application code.');
  }

  const transporter = nodemailer.createTransport({
    host,
    port,
    secure: port === 465,
    auth: user && pass ? { user, pass } : undefined,
    tls: {
      rejectUnauthorized: false,
    },
  });

  console.log('\n[1/2] Verifying SMTP connection & authentication credentials...');

  try {
    const verified = await transporter.verify();
    console.log('✅ SUCCESS: SMTP Server is reachable and authentication credentials are VALID!');
  } catch (err: any) {
    console.error('❌ FAILED: SMTP Connection or Authentication failed!');
    console.error(`Reason: ${err.message || err}`);
    if (err.code === 'ECONNREFUSED') {
      console.error(`👉 Suggestion: Port ${port} is blocked or not accepting connections on ${host}. Check firewall rules.`);
    } else if (err.responseCode === 535 || err.code === 'EAUTH') {
      console.error('👉 Suggestion: Invalid SMTP_USER or SMTP_PASS.');
    }
    process.exit(1);
  }

  // Optional: If an email argument is provided, send a test email
  const recipient = process.argv[2];
  if (recipient) {
    console.log(`\n[2/2] Sending test email to: ${recipient}...`);
    try {
      const info = await transporter.sendMail({
        from: from || user,
        to: recipient,
        subject: 'Tech4Biz Channel Partner SMTP Verification',
        text: 'This is a test email sent from the Tech4Biz SMTP Test Script.',
        html: '<div style="font-family: sans-serif; padding: 20px; border: 1px solid #ccc;"><h3>SMTP Test Successful!</h3><p>Your backend SMTP configuration is working properly.</p></div>',
      });
      console.log(`✅ SUCCESS: Email delivered successfully to ${recipient}!`);
      console.log(`• Message ID: ${info.messageId}`);
    } catch (err: any) {
      console.error(`❌ FAILED: Could not send test email to ${recipient}.`);
      console.error(`Reason: ${err.message || err}`);
    }
  } else {
    console.log('\nℹ️  To send an actual test email, run:');
    console.log('   npx ts-node scripts/test-smtp.ts <your-email-address>');
  }
  console.log('==================================================\n');
}

main().catch((err) => {
  console.error('Unexpected error:', err);
  process.exit(1);
});