// Lightweight static file server + editor API for saving maps.js
// Used in production Docker container

const http = require('http');
const fs = require('fs');
const path = require('path');

const PORT = process.env.PORT || 80;
const STATIC_DIR = path.join(__dirname, 'public');
const MAPS_FILE = path.join(STATIC_DIR, 'js', 'world', 'maps.js');

const MIME = {
    '.html': 'text/html',
    '.css': 'text/css',
    '.js': 'application/javascript',
    '.json': 'application/json',
    '.png': 'image/png',
    '.jpg': 'image/jpeg',
    '.svg': 'image/svg+xml',
    '.ico': 'image/x-icon',
    '.woff2': 'font/woff2',
};

const server = http.createServer((req, res) => {
    // CORS headers for editor
    res.setHeader('Access-Control-Allow-Origin', '*');
    res.setHeader('Access-Control-Allow-Methods', 'GET, POST, PUT, OPTIONS');
    res.setHeader('Access-Control-Allow-Headers', 'Content-Type');

    if (req.method === 'OPTIONS') {
        res.writeHead(204);
        res.end();
        return;
    }

    // === API: GET /api/maps — read maps.js source ===
    if (req.method === 'GET' && req.url === '/api/maps') {
        fs.readFile(MAPS_FILE, 'utf-8', (err, data) => {
            if (err) {
                res.writeHead(500, { 'Content-Type': 'application/json' });
                res.end(JSON.stringify({ error: 'Failed to read maps.js' }));
                return;
            }
            res.writeHead(200, { 'Content-Type': 'application/json' });
            res.end(JSON.stringify({ content: data }));
        });
        return;
    }

    // === API: PUT /api/maps — write maps.js source ===
    if (req.method === 'PUT' && req.url === '/api/maps') {
        let body = '';
        req.on('data', chunk => { body += chunk; });
        req.on('end', () => {
            try {
                const { content } = JSON.parse(body);
                if (!content || typeof content !== 'string') {
                    res.writeHead(400, { 'Content-Type': 'application/json' });
                    res.end(JSON.stringify({ error: 'Missing content field' }));
                    return;
                }
                // Backup before overwrite
                const backup = MAPS_FILE + '.bak';
                if (fs.existsSync(MAPS_FILE)) {
                    fs.copyFileSync(MAPS_FILE, backup);
                }
                fs.writeFileSync(MAPS_FILE, content, 'utf-8');
                console.log(`[server] maps.js saved (${content.length} bytes)`);
                res.writeHead(200, { 'Content-Type': 'application/json' });
                res.end(JSON.stringify({ ok: true, bytes: content.length }));
            } catch (e) {
                res.writeHead(400, { 'Content-Type': 'application/json' });
                res.end(JSON.stringify({ error: e.message }));
            }
        });
        return;
    }

    // === API: GET /api/maps/json — parse current map data as JSON ===
    if (req.method === 'GET' && req.url === '/api/maps/json') {
        fs.readFile(MAPS_FILE, 'utf-8', (err, data) => {
            if (err) {
                res.writeHead(500, { 'Content-Type': 'application/json' });
                res.end(JSON.stringify({ error: 'Failed to read maps.js' }));
                return;
            }
            // Extract JSON-serializable data from the JS source
            // This is a best-effort parser for the generated maps.js format
            res.writeHead(200, { 'Content-Type': 'application/json' });
            res.end(JSON.stringify({ source: data }));
        });
        return;
    }

    // === Static file serving ===
    let filePath = path.join(STATIC_DIR, req.url === '/' ? 'index.html' : req.url);
    // Prevent directory traversal
    if (!filePath.startsWith(STATIC_DIR)) {
        res.writeHead(403);
        res.end('Forbidden');
        return;
    }

    const ext = path.extname(filePath).toLowerCase();
    const contentType = MIME[ext] || 'application/octet-stream';

    fs.readFile(filePath, (err, data) => {
        if (err) {
            if (err.code === 'ENOENT') {
                res.writeHead(404);
                res.end('Not found');
            } else {
                res.writeHead(500);
                res.end('Server error');
            }
            return;
        }
        // Cache static assets
        if (ext === '.png' || ext === '.jpg' || ext === '.woff2') {
            res.setHeader('Cache-Control', 'public, max-age=86400');
        }
        res.writeHead(200, { 'Content-Type': contentType });
        res.end(data);
    });
});

server.listen(PORT, () => {
    console.log(`[server] Logic Gates running on port ${PORT}`);
    console.log(`[server] Static: ${STATIC_DIR}`);
    console.log(`[server] Maps file: ${MAPS_FILE}`);
});