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

const root = __dirname;
const startPort = Number(process.env.PORT || 5173);
const mimeTypes = {
  ".html": "text/html; charset=utf-8",
  ".css": "text/css; charset=utf-8",
  ".js": "application/javascript; charset=utf-8",
  ".svg": "image/svg+xml; charset=utf-8",
  ".json": "application/json; charset=utf-8"
};

function createServer(port) {
  const server = http.createServer((request, response) => {
    const parsed = url.parse(request.url);
    const pathname = decodeURIComponent(parsed.pathname === "/" ? "/index.html" : parsed.pathname);
    let filePath = path.resolve(root, "." + pathname);

    if (!filePath.startsWith(root)) {
      response.writeHead(403);
      response.end("Forbidden");
      return;
    }

    if (!fs.existsSync(filePath) && pathname.endsWith(".html") && pathname !== "/index.html") {
      filePath = path.resolve(root, "./pages" + pathname);
    }

    fs.readFile(filePath, (error, content) => {
      if (error) {
        response.writeHead(404);
        response.end("Not found");
        return;
      }
      response.writeHead(200, {
        "Content-Type": mimeTypes[path.extname(filePath)] || "application/octet-stream"
      });
      response.end(content);
    });
  });

  server.on("error", (error) => {
    if (error.code === "EADDRINUSE" && port < startPort + 20) {
      createServer(port + 1);
      return;
    }
    throw error;
  });

  server.listen(port, () => {
    console.log("visitor-admin-ui running at http://localhost:" + port + "/");
  });
}

createServer(startPort);