const express = require('express');
const path = require('path');
const bodyParser = require('body-parser');
const crypto = require('crypto');
const { exec } = require('child_process');
require('dotenv').config();

const app = express();
const PORT = process.env.PORT || 3000;
const GITEA_SECRET = process.env.GITEA_SECRET

// Serve static files from the 'public' directory
app.use(express.static(path.join(__dirname, 'public')));

// Middleware to capture raw body
app.use(bodyParser.json({
	verify: (req, res, buf, encoding) => {
	  req.rawBody = buf.toString(encoding || 'utf8');
	}
}));

// Custom middleware to handle URLs without .html for specific routes
app.use((req, res, next) => {
  const urlPath = req.path.split('?')[0];
  const htmlRoutes = ['/about', '/list', '/gallery'];

  if (htmlRoutes.includes(urlPath)) {
    req.url += '.html';
  }

  next();
});

// Route to serve the index.html file
app.get('/', (req, res) => {
  res.sendFile(path.join(__dirname, 'public', 'index.html'));
});

// Routes to serve the HTML files without .html extension
app.get('/about.html', (req, res) => {
  res.sendFile(path.join(__dirname, 'public', 'about.html'));
});

app.get('/list.html', (req, res) => {
  res.sendFile(path.join(__dirname, 'public', 'list.html'));
});

app.get('/gallery.html', (req, res) => {
  res.sendFile(path.join(__dirname, 'public', 'gallery.html'));
});

// Serve articles without .html extension
app.get('/articles/:articleName', (req, res) => {
  const articleName = req.params.articleName;
  res.sendFile(path.join(__dirname, 'public/articles', `${articleName}.html`));
});

// Webhook handler
app.post('/api', (req, res) => {
	const signature = req.headers['x-gitea-signature'];
	const payload = req.rawBody;
  
	if (!signature || !payload) {
	  return res.status(400).send('Invalid payload or missing signature');
	}
  
	// Verify the secret
	const hmac = crypto.createHmac('sha256', GITEA_SECRET);
	const digest = hmac.update(payload).digest('hex');  
	const bufferSignature = Buffer.from(signature, 'hex');
	const bufferDigest = Buffer.from(digest, 'hex');
  
	if (bufferSignature.length === bufferDigest.length && crypto.timingSafeEqual(bufferSignature, bufferDigest)) {
	  // Secret is valid, update the repository
	  res.status(200).send('Repository updated successfully');
	  // Optionally, execute a shell command to pull the latest changes
	  exec('git pull', (error, stdout, stderr) => {
		if (error) {
		  console.error(`exec error: ${error}`);
		  return;
		}
		console.log(`stdout: ${stdout}`);
		console.error(`stderr: ${stderr}`);
	  });
	} else {
	  res.status(401).send('Invalid secret');
	}
});

// Error handling
app.use((err, req, res, next) => {
  console.error(err.stack);
  res.status(500).send('Something broke!');
});

// Start the server
app.listen(PORT, (err) => {
  if (err) {
    console.error('Error starting the server:', err);
    process.exit(1);
  }
  console.log(`Server is running on http://localhost:${PORT}`);
});