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

const PORT = 80;
const ROOT = '/app';

function corsHeaders(extra = {}) {
    return {
        'Access-Control-Allow-Origin': '*',
        'Access-Control-Allow-Methods': 'GET, POST, OPTIONS, HEAD',
        'Access-Control-Allow-Headers': 'Content-Type, X-Requested-With',
        ...extra
    };
}

function sendFile(req, res, filePath, contentType) {
    if (!fs.existsSync(filePath)) {
        res.writeHead(404);
        return res.end('Not Found');
    }

    const stat = fs.statSync(filePath);

    res.writeHead(200, {
        ...corsHeaders(),
        'Content-Type': contentType,
        'Content-Length': stat.size,
        'Cache-Control': 'no-store, no-cache, must-revalidate, max-age=0'
    });

    if (req.method !== 'HEAD') {
        fs.createReadStream(filePath).pipe(res);
    } else {
        res.end();
    }
}

function contentType(file) {
    const ext = path.extname(file).toLowerCase();

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

    return types[ext] || 'application/octet-stream';
}

const server = http.createServer((req, res) => {
    const parsed = url.parse(req.url);
    const pathname = parsed.pathname;

    // CORS preflight
    if (req.method === 'OPTIONS') {
        res.writeHead(200, corsHeaders());
        return res.end();
    }

    // Get client IP
    if (pathname === '/getIP') {
        const ip =
            req.headers['x-forwarded-for']?.split(',')[0].trim() ||
            req.socket.remoteAddress ||
            '';

        res.writeHead(200, {
            ...corsHeaders(),
            'Content-Type': 'text/plain',
            'Cache-Control': 'no-store'
        });

        return res.end(ip);
    }

    // Upload endpoint
    if (pathname === '/upload') {
        if (req.method !== 'POST') {
            res.writeHead(200, corsHeaders());
            return res.end('OK');
        }

        let bytes = 0;

        req.on('data', chunk => {
            bytes += chunk.length;
        });

        req.on('end', () => {
            res.writeHead(200, {
                ...corsHeaders(),
                'Content-Type': 'text/plain',
                'Cache-Control': 'no-store'
            });

            res.end('OK');
        });

        req.on('error', () => {
            if (!res.headersSent) {
                res.writeHead(500, corsHeaders());
            }
            res.end('ERROR');
        });

        return;
    }

    // Download endpoint
    if (pathname === '/downloading') {
        const file = path.join(ROOT, 'downloading');

        if (!fs.existsSync(file)) {
            res.writeHead(404);
            return res.end('Not Found');
        }

        const stat = fs.statSync(file);

        res.writeHead(200, {
            ...corsHeaders(),
            'Content-Type': 'application/octet-stream',
            'Content-Length': stat.size,
            'Cache-Control': 'no-store, no-cache, must-revalidate, max-age=0',
            'Content-Disposition': 'inline'
        });

        if (req.method !== 'HEAD') {
            fs.createReadStream(file).pipe(res);
        } else {
            res.end();
        }

        return;
    }

    // Static files
    let requested = pathname === '/' ? '/index.html' : pathname;
    const filePath = path.normalize(path.join(ROOT, requested));

    // Prevent path traversal
    if (!filePath.startsWith(ROOT)) {
        res.writeHead(403);
        return res.end('Forbidden');
    }

    if (!fs.existsSync(filePath) || !fs.statSync(filePath).isFile()) {
        res.writeHead(404);
        return res.end('Not Found');
    }

    sendFile(req, res, filePath, contentType(filePath));
});

server.listen(PORT, '0.0.0.0', () => {
    console.log(`Speedtest server listening on port ${PORT}`);
});