/**
 * Development server with livereload.
 *
 * Serves the test page and ribbit dist files. Watches src/ for
 * changes, rebuilds automatically, and notifies connected browsers
 * to reload via a simple EventSource stream.
 *
 * Run: npm run dev
 */
const { createServer } = require('./server');
const { execSync } = require('child_process');
const fs = require('fs');
const path = require('path');

const PORT = 8080;
const WATCH_DIRS = [
    path.join(__dirname, '..', '..', 'src'),
    path.join(__dirname, '..', '..', 'test', 'integration'),
];
const DEBOUNCE_MS = 300;

const server = createServer(PORT);
const reloadClients = [];

// Patch the server to add the livereload endpoint
const originalServer = require('http').createServer;
const httpServer = server._server || (() => {
    // Access the internal server by starting and intercepting
    let captured = null;
    const origListen = require('http').Server.prototype.listen;
    require('http').Server.prototype.listen = function (...args) {
        captured = this;
        return origListen.apply(this, args);
    };
    server.start();
    require('http').Server.prototype.listen = origListen;
    return captured;
})();

// Simpler approach: create a standalone livereload server
const reloadServer = require('http').createServer((request, response) => {
    response.writeHead(200, {
        'Content-Type': 'text/event-stream',
        'Cache-Control': 'no-cache',
        'Connection': 'keep-alive',
        'Access-Control-Allow-Origin': '*',
    });
    reloadClients.push(response);
    request.on('close', () => {
        const index = reloadClients.indexOf(response);
        if (index >= 0) {
            reloadClients.splice(index, 1);
        }
    });
});

function notifyReload() {
    for (const client of reloadClients) {
        client.write('data: reload\n\n');
    }
}

function rebuild() {
    try {
        console.log('\n🔨 Rebuilding...');
        execSync('npm run build:js && npm run build:css', {
            cwd: path.join(__dirname, '..', '..'),
            stdio: 'pipe',
        });
        console.log('✅ Build complete');
        notifyReload();
    } catch (error) {
        console.error('❌ Build failed:', error.stderr?.toString().slice(0, 500));
    }
}

let debounceTimer = null;
function onFileChange(filename) {
    if (debounceTimer) {
        clearTimeout(debounceTimer);
    }
    console.log(`📝 Changed: ${filename}`);
    debounceTimer = setTimeout(rebuild, DEBOUNCE_MS);
}

// Watch source directories
for (const directory of WATCH_DIRS) {
    if (fs.existsSync(directory)) {
        fs.watch(directory, { recursive: true }, (eventType, filename) => {
            if (filename && !filename.includes('node_modules')) {
                onFileChange(filename);
            }
        });
    }
}

server.start().then(() => {
    reloadServer.listen(PORT + 1, () => {
        console.log(`\n🐸 Ribbit dev server`);
        console.log(`   Editor:     http://localhost:${PORT}`);
        console.log(`   Livereload: http://localhost:${PORT + 1} (EventSource)`);
        console.log(`   Watching:   src/, test/integration/`);
        console.log(`\n   Add this to the page to enable livereload:`);
        console.log(`   <script>new EventSource('http://localhost:${PORT + 1}').onmessage = () => location.reload()</script>\n`);
    });
});