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

const PORT = process.env.PORT || 3000;
const IMMICH_URL = process.env.IMMICH_URL || 'http://immich-server:2283';
const immichParsed = new URL(IMMICH_URL);

// Timeouts for large uploads (10 minutes)
const UPLOAD_TIMEOUT = 10 * 60 * 1000;

// Load the custom JS to inject
const customJS = fs.readFileSync(path.join(__dirname, 'live-search.js'), 'utf8');
const SCRIPT_TAG = `<script>${customJS}</script>`;

// Helper: make an internal request to Immich (for small JSON requests only)
function immichRequest(method, apiPath, headers, body) {
    return new Promise((resolve, reject) => {
        const url = new URL(apiPath, IMMICH_URL);
        const opts = {
            hostname: url.hostname,
            port: url.port || 80,
            path: url.pathname + url.search,
            method,
            headers: { ...headers, host: url.host }
        };
        delete opts.headers['accept-encoding'];

        const req = http.request(opts, (res) => {
            let chunks = [];
            res.on('data', c => chunks.push(c));
            res.on('end', () => {
                const data = Buffer.concat(chunks).toString('utf8');
                resolve({ status: res.statusCode, headers: res.headers, body: data });
            });
        });
        req.on('error', reject);
        if (body) req.write(body);
        req.end();
    });
}

const server = http.createServer((req, res) => {
    // --- Custom endpoint: batch fetch exif (needs buffered body) ---
    if (req.url === '/api/custom/batch-exif' && req.method === 'POST') {
        let bodyChunks = [];
        req.on('data', chunk => bodyChunks.push(chunk));
        req.on('end', async () => {
            const body = Buffer.concat(bodyChunks);
            try {
                const { ids } = JSON.parse(body.toString());
                const authHeader = req.headers['authorization'] || '';
                const apiKey = req.headers['x-api-key'] || '';
                const hdrs = { 'Content-Type': 'application/json' };
                if (authHeader) hdrs['Authorization'] = authHeader;
                if (apiKey) hdrs['x-api-key'] = apiKey;

                const results = await Promise.all(ids.map(async (id) => {
                    try {
                        const r = await immichRequest('GET', `/api/assets/${id}`, hdrs);
                        if (r.status === 200) {
                            const asset = JSON.parse(r.body);
                            const exif = asset.exifInfo || {};
                            return {
                                id,
                                latitude: exif.latitude || null,
                                longitude: exif.longitude || null,
                                city: exif.city || null,
                                state: exif.state || null,
                                country: exif.country || null
                            };
                        }
                    } catch {}
                    return { id, latitude: null, longitude: null };
                }));

                res.writeHead(200, { 'Content-Type': 'application/json' });
                res.end(JSON.stringify(results));
            } catch (e) {
                res.writeHead(400, { 'Content-Type': 'application/json' });
                res.end(JSON.stringify({ error: e.message }));
            }
        });
        return;
    }

    // --- Standard streaming proxy ---
    const targetUrl = new URL(req.url, IMMICH_URL);
    const headers = { ...req.headers };
    headers.host = targetUrl.host;
    delete headers['accept-encoding'];

    const proxyOpts = {
        hostname: targetUrl.hostname,
        port: targetUrl.port || 80,
        path: req.url,
        method: req.method,
        headers,
        timeout: UPLOAD_TIMEOUT
    };

    const proxyReq = http.request(proxyOpts, (proxyRes) => {
        const contentType = proxyRes.headers['content-type'] || '';
        const isHTML = contentType.includes('text/html');

        if (isHTML) {
            // Buffer HTML only to inject script tag
            let htmlChunks = [];
            proxyRes.on('data', chunk => htmlChunks.push(chunk));
            proxyRes.on('end', () => {
                let html = Buffer.concat(htmlChunks).toString('utf8');
                html = html.replace('</body>', SCRIPT_TAG + '</body>');

                const resHeaders = { ...proxyRes.headers };
                delete resHeaders['content-length'];
                delete resHeaders['content-encoding'];
                resHeaders['content-type'] = 'text/html; charset=utf-8';

                res.writeHead(proxyRes.statusCode, resHeaders);
                res.end(html);
            });
        } else {
            // Stream non-HTML responses directly (videos, images, API JSON)
            res.writeHead(proxyRes.statusCode, proxyRes.headers);
            proxyRes.pipe(res);
        }
    });

    proxyReq.on('error', (e) => {
        console.error('Proxy error:', e.message);
        if (!res.headersSent) {
            res.writeHead(502, { 'Content-Type': 'text/plain' });
            res.end('Bad Gateway');
        }
    });

    proxyReq.on('timeout', () => {
        console.error('Proxy request timed out');
        proxyReq.destroy();
        if (!res.headersSent) {
            res.writeHead(504, { 'Content-Type': 'text/plain' });
            res.end('Gateway Timeout');
        }
    });

    // Stream request body directly to Immich (no buffering)
    req.pipe(proxyReq);
});

// WebSocket proxy — handle HTTP upgrade events
server.on('upgrade', (req, clientSocket, head) => {
    const targetHost = immichParsed.hostname;
    const targetPort = immichParsed.port || 80;

    const proxySocket = net.connect(targetPort, targetHost, () => {
        // Reconstruct the HTTP upgrade request to forward
        const reqHeaders = [`${req.method} ${req.url} HTTP/1.1`];
        for (const [key, value] of Object.entries(req.headers)) {
            if (key.toLowerCase() === 'host') {
                reqHeaders.push(`Host: ${targetHost}:${targetPort}`);
            } else {
                reqHeaders.push(`${key}: ${value}`);
            }
        }
        reqHeaders.push('', '');

        proxySocket.write(reqHeaders.join('\r\n'));
        if (head.length > 0) proxySocket.write(head);

        // Bidirectional pipe
        proxySocket.pipe(clientSocket);
        clientSocket.pipe(proxySocket);
    });

    proxySocket.on('error', (e) => {
        console.error('WebSocket proxy error:', e.message);
        clientSocket.destroy();
    });

    clientSocket.on('error', (e) => {
        console.error('WebSocket client error:', e.message);
        proxySocket.destroy();
    });
});

// Increase server timeouts for large uploads
server.timeout = UPLOAD_TIMEOUT;
server.requestTimeout = UPLOAD_TIMEOUT;
server.headersTimeout = UPLOAD_TIMEOUT + 1000;
server.keepAliveTimeout = UPLOAD_TIMEOUT;

server.listen(PORT, '0.0.0.0', () => {
    console.log(`Immich proxy with live search running on port ${PORT}`);
    console.log(`Proxying to: ${IMMICH_URL}`);
    console.log(`Upload timeout: ${UPLOAD_TIMEOUT / 1000}s`);
});