'use strict';

const http = require('node:http');
const { spawn } = require('node:child_process');
const path = require('node:path');
const { createLogger, createModuleServer, loadManifest } = require('./platform-module-sdk.cjs');

const manifest = loadManifest(path.join(__dirname, 'module.json'));
const logger = createLogger({ moduleId: manifest.id });
const basePath = process.env.HUB_BASE_PATH || `/${manifest.slug}`;
const nextPort = 3001;
let shuttingDown = false;

const nextServer = spawn(process.execPath, ['server.js'], {
  cwd: __dirname,
  env: { ...process.env, HOSTNAME: '127.0.0.1', PORT: String(nextPort) },
  stdio: 'inherit',
});

nextServer.once('exit', (code) => {
  if (shuttingDown) return;
  logger.error('Next.js-Prozess wurde beendet', { code });
  process.exit(code || 1);
});

const server = createModuleServer({
  manifest,
  logger,
  identityRequired: true,
  routes(request, response, context) {
    const targetPath = `${basePath}${context.url.pathname}${context.url.search}`;
    const headers = { ...request.headers, host: `127.0.0.1:${nextPort}` };
    for (const name of Object.keys(headers)) {
      if (name.startsWith('x-kalendartool-mpm-')) delete headers[name];
    }
    headers['x-kalendartool-mpm-user-id'] = context.identity.userId;
    headers['x-kalendartool-mpm-username'] = context.identity.username;
    headers['x-kalendartool-mpm-display-name'] = context.identity.displayName || context.identity.username;
    headers['x-kalendartool-mpm-role'] = context.identity.role;

    const upstream = http.request({
      host: '127.0.0.1',
      port: nextPort,
      method: request.method,
      path: targetPath,
      headers,
    }, (upstreamResponse) => {
      response.writeHead(upstreamResponse.statusCode || 502, upstreamResponse.headers);
      upstreamResponse.pipe(response);
    });
    upstream.on('error', () => {
      if (!response.headersSent) {
        response.writeHead(502, { 'Content-Type': 'application/json' });
        response.end(JSON.stringify({ statusCode: 502, message: 'Kalendertool ist noch nicht bereit' }));
      } else {
        response.end();
      }
    });
    request.pipe(upstream);
  },
});

function waitForNext(attempt = 0) {
  const probe = http.get({
    host: '127.0.0.1',
    port: nextPort,
    path: `${basePath}/api/manifest`,
    headers: {
      'x-kalendartool-mpm-user-id': 'readiness-probe',
      'x-kalendartool-mpm-username': 'readiness-probe',
      'x-kalendartool-mpm-display-name': 'readiness-probe',
      'x-kalendartool-mpm-role': 'USER',
    },
  }, (response) => {
    response.resume();
    if (response.statusCode === 200) {
      const port = Number(process.env.PORT || manifest.port);
      server.listen(port, '0.0.0.0', () => logger.info('MPM-Modulserver gestartet', { port }));
      return;
    }
    retry(attempt);
  });
  probe.on('error', () => retry(attempt));
}

function retry(attempt) {
  if (attempt >= 119) {
    logger.error('Next.js wurde nicht rechtzeitig bereit');
    process.exit(1);
  }
  setTimeout(() => waitForNext(attempt + 1), 250);
}

waitForNext();

function shutdown() {
  shuttingDown = true;
  if (server.listening) server.close();
  nextServer.kill('SIGTERM');
}
process.once('SIGTERM', shutdown);
process.once('SIGINT', shutdown);