import 'dotenv/config';
import path from 'path';
import { fileURLToPath } from 'url';
import cors from 'cors';
import cron from 'node-cron';
import express, { type NextFunction, type Request, type Response } from 'express';
import { buildApiPath, getConfig } from './config';
import { TursoClient } from './lib/db';
import { createHealthRouter } from './routes/health';
import { createTodosRouter } from './routes/todos';

const __dirname = path.dirname(fileURLToPath(import.meta.url));

const config = getConfig();
const app = express();
const db = new TursoClient(config);

app.disable('x-powered-by');
app.use(cors({ origin: config.corsOrigin === '*' ? true : config.corsOrigin }));
app.use(express.json({ limit: '1mb' }));

const apiRoot = config.apiPrefix || '/';
app.use(apiRoot, createHealthRouter(config));
app.use(apiRoot, createTodosRouter(config, db));

cron.schedule('*/3 * * * *', () => {
  console.log('[Cron A] Heartbeat executing every 3 minutes: ' + new Date().toISOString());
});

cron.schedule('*/10 * * * *', () => {
  console.log('[Cron B] Heartbeat executing every 10 minutes: ' + new Date().toISOString());
});

app.post('/_cron/tick', (req, res) => {
  const token = req.headers.authorization?.replace(/^Bearer\s+/i, '') || '';
  const expected = process.env.CRON_TOKEN || '';
  if (!expected || token !== expected) {
    res.status(401).json({ success: false, error: 'Invalid cron token' });
    return;
  }
  console.log('[Tick] Heartbeat received. Waking up event loop.');
  res.status(200).json({ success: true });
});

const publicDir = path.join(__dirname, '../public');
app.use(express.static(publicDir));

app.get('/{*path}', (req, res, next) => {
  if (req.path.startsWith(apiRoot)) return next();
  if (req.path === '/_cron/tick') return next();
  
  // Do not serve HTML for static assets or requests that do not accept HTML
  const isAsset = /\.[a-z0-9]{2,4}$/i.test(req.path);
  const acceptsHtml = req.headers.accept?.includes('text/html');
  if (isAsset || !acceptsHtml) {
    res.status(404).json({ success: false, error: 'Not found' });
    return;
  }
  
  if (req.path.startsWith('/mobile')) {
    res.sendFile(path.join(publicDir, 'mobile/index.html'), (err) => {
      if (err) next();
    });
    return;
  }
  
  if (req.path.startsWith('/games')) {
    res.sendFile(path.join(publicDir, 'games/index.html'), (err) => {
      if (err) next();
    });
    return;
  }
  
  res.sendFile(path.join(publicDir, 'index.html'), (err) => {
    if (err) next();
  });
});

app.use((_req, res) => {
  res.status(404).json({ success: false, error: 'Not found' });
});

app.use((error: Error, _req: Request, res: Response, _next: NextFunction) => {
  const status = /required|invalid|missing/i.test(error.message) ? 400 : 500;
  res.status(status).json({
    success: false,
    error: error.message || 'Unhandled error',
  });
});

app.listen(config.port, '0.0.0.0', () => {
  const healthPath = buildApiPath(config, '/health');
  console.log(`Backend todo template listening on port ${config.port}`);
  console.log(`Health check available at ${healthPath}`);
});