import path from "node:path";
import { fileURLToPath } from "node:url";
import cors from "cors";
import express from "express";
import { createProxyMiddleware } from "http-proxy-middleware";

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

const app = express();
const PORT = process.env.PORT || 3000;
const BACKEND_URL = process.env.BACKEND_URL || "http://backend:3001";

// Enable CORS for API calls
app.use(
	cors({
		origin: process.env.CORS_ORIGIN || "*",
		credentials: true,
	}),
);

// Proxy API requests to backend
app.use(
	"/api",
	createProxyMiddleware({
		target: BACKEND_URL,
		changeOrigin: true,
		logLevel: "info",
		onError: (err, _req, res) => {
			console.error("Proxy error:", err.message);
			res.status(500).json({ error: "Backend service unavailable" });
		},
		onProxyReq: (_proxyReq, req, _res) => {
			console.log(`Proxying ${req.method} ${req.path} to ${BACKEND_URL}`);
		},
	}),
);

// Serve static files from dist directory
app.use(express.static(path.join(__dirname, "dist")));

// Handle SPA routing - serve index.html for all routes
app.get("*", (_req, res) => {
	res.sendFile(path.join(__dirname, "dist", "index.html"));
});

app.listen(PORT, () => {
	console.log(`Frontend server running on port ${PORT}`);
	console.log(`Serving from: ${path.join(__dirname, "dist")}`);
});