require('dotenv').config();
const express = require('express');
const { exec } = require('child_process');
const axios = require('axios');
const nodemailer = require('nodemailer');

const INTERVAL_MINUTES = 30;
const MAX_RETRIES = 3;
const PORT = process.env.PORT || 3000;
const app = express();
let lastStatus = { success: null, message: null, timestamp: null, duration: null };

function runCheck(attempt = 1) {
  const startTs = Date.now();
  console.log(`[{new Date().toISOString()}] ▶️ Starting OIDC check (try {attempt}/{MAX_RETRIES})...`);

  const child = exec('node /app/test/monitor.js', (error, stdout, stderr) => {
    lastStatus.timestamp = new Date().toISOString();
    lastStatus.duration = Date.now() - startTs;

    if (stdout) console.log(stdout);
    if (stderr) console.error(stderr);

    lastStatus.success = !error;
    lastStatus.message = error ? `Fehlgeschlagen: ${error.message}` : 'Login erfolgreich';

    if (error) {
      notifySlack(`Fehler beim Login:\n${lastStatus.message}`);
      sendEmail('❌ OIDC Monitoring Fehler', `Zeit: ${lastStatus.timestamp}\n${lastStatus.message}`);
    }

    pushToPrometheus(!error, lastStatus.duration);
  });
}

function pushToPrometheus(success, duration) {
  const labels = `{job="oidc-monitor",instance="${process.env.PROMETHEUS_INSTANCE_ID}"}`;
  const metrics = `
oidc_login_success${labels} ${success ? 1 : 0}
oidc_login_duration_seconds${labels} ${(duration / 1000).toFixed(2)}
`;
  axios.post(`${process.env.PUSHGATEWAY_URL}/metrics/job/oidc-monitor`, metrics, {
    headers: { 'Content-Type': 'text/plain' }
  }).then(() => console.log('📡 Prometheus Push erfolgreich'))
    .catch(err => console.error('❌ Prometheus Push fehlgeschlagen:', err.message));
}

function notifySlack(message) {
  if (!process.env.SLACK_WEBHOOK_URL) return;
  axios.post(process.env.SLACK_WEBHOOK_URL, { text: `❗️OIDC Monitoring Alert:\n${message}` })
    .then(() => console.log('📣 Slack-Nachricht gesendet'))
    .catch(err => console.error('❌ Slack fehlgeschlagen:', err.message));
}

function sendEmail(subject, text) {
  const transporter = nodemailer.createTransport({
    host: process.env.SMTP_HOST,
    port: parseInt(process.env.SMTP_PORT || '25', 10),
    secure: false
  });
  transporter.sendMail({
    from: process.env.MAIL_FROM,
    to: process.env.MAIL_TO,
    subject,
    text
  }).then(() => console.log('✉️ E-Mail gesendet'))
    .catch(err => console.error('❌ Mail fehlgeschlagen:', err.message));
}

app.get('/run-now', (req, res) => { runCheck(); res.send('▶️ Check gestartet'); });
app.get('/healthz', (req, res) => {
  if (lastStatus.success === false) return res.status(500).send('Letzter Check fehlgeschlagen');
  res.send('OK');
});
app.get('/status', (req, res) => res.json(lastStatus));

app.listen(PORT, () => {
  console.log(`🌐 Web API läuft auf Port ${PORT}`);
});

runCheck();
setInterval(runCheck, INTERVAL_MINUTES * 60 * 1000);