// LosaDev Tools production server: serves the Vite build in dist/ with no extra dependencies.
// Settings come from .env next to this file (or the real environment, which wins):
//   PORT  port to listen on (default 4700)
//   HOST  address to bind (default 0.0.0.0; use 127.0.0.1 behind a reverse proxy)
// The tools read game files in the visitor's browser (File System Access API), which needs HTTPS
// on a real domain: put this behind the panel's reverse proxy with a certificate.
import http from "node:http";
import fs from "node:fs";
import path from "node:path";
import zlib from "node:zlib";
import { fileURLToPath } from "node:url";

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

function loadEnv(file) {
	let text;
	try {
		text = fs.readFileSync(file, "utf8");
	} catch {
		return;
	}
	for (const raw of text.split(/\r?\n/)) {
		const line = raw.trim();
		if (!line || line.startsWith("#")) continue;
		const eq = line.indexOf("=");
		if (eq < 1) continue;
		const key = line.slice(0, eq).trim();
		let value = line.slice(eq + 1).trim();
		if (/^(["']).*\1$/.test(value)) value = value.slice(1, -1);
		if (process.env[key] === undefined) process.env[key] = value;
	}
}
loadEnv(path.join(here, ".env"));

const PORT = Number.parseInt(process.env.PORT, 10) || 4700;
const HOST = process.env.HOST || "0.0.0.0";
const ROOT = path.join(here, "dist");

if (!fs.existsSync(path.join(ROOT, "index.html"))) {
	console.error("dist/index.html not found. Run `npm run build` first (or `npm run rebuild`).");
	process.exit(1);
}

const TYPES = {
	".html": "text/html; charset=utf-8",
	".js": "text/javascript; charset=utf-8",
	".mjs": "text/javascript; charset=utf-8",
	".css": "text/css; charset=utf-8",
	".json": "application/json; charset=utf-8",
	".map": "application/json; charset=utf-8",
	".svg": "image/svg+xml",
	".png": "image/png",
	".jpg": "image/jpeg",
	".jpeg": "image/jpeg",
	".webp": "image/webp",
	".gif": "image/gif",
	".ico": "image/x-icon",
	".woff": "font/woff",
	".woff2": "font/woff2",
	".ttf": "font/ttf",
	".wasm": "application/wasm",
	".txt": "text/plain; charset=utf-8",
	".xml": "application/xml; charset=utf-8",
	".ini": "text/plain; charset=utf-8",
};
const COMPRESS = /^(text\/|application\/(json|javascript|xml|wasm)|image\/svg)/;

function resolveFile(urlPath) {
	let rel;
	try {
		rel = decodeURIComponent(urlPath.split("?")[0]);
	} catch {
		return null;
	}
	const full = path.normalize(path.join(ROOT, rel));
	if (full !== ROOT && !full.startsWith(ROOT + path.sep)) return null; // no ../ out of dist
	try {
		const st = fs.statSync(full);
		if (st.isDirectory()) {
			const index = path.join(full, "index.html");
			return fs.existsSync(index) ? index : null;
		}
		return full;
	} catch {
		// Routes without a file extension fall back to the app (it routes by #hash, this is a safety net).
		return path.extname(rel) ? null : path.join(ROOT, "index.html");
	}
}

const server = http.createServer((req, res) => {
	res.setHeader("X-Content-Type-Options", "nosniff");
	res.setHeader("Referrer-Policy", "strict-origin-when-cross-origin");
	if (req.method !== "GET" && req.method !== "HEAD") {
		res.writeHead(405, { Allow: "GET, HEAD" });
		return res.end();
	}
	const file = resolveFile(req.url || "/");
	if (!file) {
		res.writeHead(404, { "Content-Type": "text/plain; charset=utf-8" });
		return res.end("Not found");
	}
	const type = TYPES[path.extname(file).toLowerCase()] || "application/octet-stream";
	// Vite puts content-hashed files in /assets/: cache them for a year. Everything else
	// (index.html, legacy/ files that use a ?v= query) is revalidated on every visit.
	const hashed = req.url.startsWith("/assets/");
	const headers = { "Content-Type": type, "Cache-Control": hashed ? "public, max-age=31536000, immutable" : "no-cache" };
	const gzip = COMPRESS.test(type) && /\bgzip\b/.test(req.headers["accept-encoding"] || "");
	if (gzip) {
		headers["Content-Encoding"] = "gzip";
		headers.Vary = "Accept-Encoding";
	} else {
		headers["Content-Length"] = fs.statSync(file).size;
	}
	res.writeHead(200, headers);
	if (req.method === "HEAD") return res.end();
	const stream = fs.createReadStream(file);
	stream.on("error", () => res.destroy());
	(gzip ? stream.pipe(zlib.createGzip()) : stream).pipe(res);
});

server.listen(PORT, HOST, () => console.log(`LosaDev Tools on http://${HOST === "0.0.0.0" ? "localhost" : HOST}:${PORT}`));