import express, { Request, Response } from 'express';
import multer from 'multer';
import fs from 'fs/promises';
import path from 'path';
import { CONFIG } from './config.js';
import { addScreenshot, getScreenshotPath } from './storage.js';
import { generateScreenshotId, notifyNewScreenshot } from './utils.js';
export function createHttpServer() {
const app = express();
// CORS middleware for development
app.use((req, res, next) => {
res.header('Access-Control-Allow-Origin', '*');
res.header('Access-Control-Allow-Headers', 'Content-Type');
res.header('Access-Control-Allow-Methods', 'GET, POST, OPTIONS');
if (req.method === 'OPTIONS') {
res.sendStatus(200);
} else {
next();
}
});
app.use(express.json());
// Auto-discovery ping endpoint
app.get('/ping', (req: Request, res: Response) => {
// Get the actual port from the server instance
const actualPort = req.socket.localPort || CONFIG.HTTP_PORT;
res.json({
name: 'exposnap-mcp-server',
service: 'exposnap',
version: CONFIG.SERVER_VERSION,
status: 'ready',
port: actualPort,
});
});
// Discovery endpoint that also logs the connection
app.get('/discover', (req: Request, res: Response) => {
const actualPort = req.socket.localPort || CONFIG.HTTP_PORT;
console.error(`[ExpoSnap] Discovery request from ${req.ip}`);
res.json({
name: 'exposnap-mcp-server',
service: 'exposnap',
version: CONFIG.SERVER_VERSION,
status: 'ready',
port: actualPort,
timestamp: Date.now(),
});
});
// Configure multer for file uploads
const upload = multer({
dest: CONFIG.SCREENSHOTS_DIR,
});
app.post(
'/screenshot',
upload.single('screenshot'),
async (req: Request, res: Response) => {
const file = req.file;
if (!file) {
return res.status(400).json({ error: 'No image provided' });
}
// Generate unique filename
const id = generateScreenshotId();
const ext = path.extname(file.originalname) || '.png';
const newFilename = `${id}${ext}`;
const newPath = getScreenshotPath(newFilename);
await fs.rename(file.path, newPath);
const rawDescription =
typeof req.body?.description === 'string'
? req.body.description.trim()
: '';
const description =
rawDescription.length > 0 ? rawDescription : undefined;
await addScreenshot({
id,
timestamp: Date.now(),
source: 'expo',
filename: newFilename,
description,
});
// Notify that new screenshot is available
notifyNewScreenshot(newPath);
res.json({ success: true, path: newPath, id });
}
);
return app;
}
async function findAvailablePort(startPort: number): Promise<number> {
const net = await import('net');
return new Promise((resolve, reject) => {
const server = net.createServer();
server.listen(startPort, () => {
const port = (server.address() as { port: number })?.port;
server.close(() => resolve(port));
});
server.on('error', () => {
// Port is in use, try next one
findAvailablePort(startPort + 1)
.then(resolve)
.catch(reject);
});
});
}
export async function startHttpServer(): Promise<number> {
const app = createHttpServer();
// If port is 0, use dynamic allocation
// Otherwise start from configured port and auto-increment if needed
const requestedPort = CONFIG.HTTP_PORT;
const port = requestedPort === 0 ? 0 : await findAvailablePort(requestedPort);
return new Promise((resolve, reject) => {
const server = app.listen(port, (err?: Error) => {
if (err) {
console.error(`[ExpoSnap] Failed to start HTTP server:`, err);
reject(err);
return;
}
const actualPort =
(server.address() as { port: number } | null)?.port || port;
console.error(`[ExpoSnap] HTTP server running on port ${actualPort}`);
resolve(actualPort);
});
server.on('error', (err: Error) => {
console.error(`[ExpoSnap] HTTP server error:`, err);
reject(err);
});
});
}
