import { createServer } from "node:http";
import { readFile } from "node:fs/promises";
import { dirname, extname, join, normalize, resolve } from "node:path";
import { fileURLToPath } from "node:url";
import { stripTypeScriptTypes } from "node:module";

const scriptDir = dirname(fileURLToPath(import.meta.url));
const root = resolve(scriptDir, "..");
const requestedPort = Number(process.env.PORT || 5173);
const host = process.env.HOST || "127.0.0.1";

const mimeByExtension = {
  ".css": "text/css; charset=utf-8",
  ".html": "text/html; charset=utf-8",
  ".js": "text/javascript; charset=utf-8",
  ".json": "application/json; charset=utf-8",
  ".ts": "text/javascript; charset=utf-8",
  ".txt": "text/plain; charset=utf-8"
};

function requestPathToFile(url) {
  const parsed = new URL(url, `http://${host}:${requestedPort}`);
  const rawPath = parsed.pathname === "/" ? "/index.html" : parsed.pathname;
  const safePath = normalize(rawPath).replace(/^(\.\.[/\\])+/, "");
  const filePath = join(root, safePath);

  if (!filePath.startsWith(root)) {
    return null;
  }

  return filePath;
}

async function handleRequest(request, response) {
  try {
    const filePath = requestPathToFile(request.url || "/");
    if (!filePath) {
      response.writeHead(403);
      response.end("Forbidden");
      return;
    }

    const extension = extname(filePath);
    let body = await readFile(filePath, "utf8");

    if (extension === ".ts") {
      body = stripTypeScriptTypes(body, { mode: "strip" });
    }

    response.writeHead(200, {
      "content-type": mimeByExtension[extension] || "application/octet-stream",
      "cache-control": "no-store"
    });
    response.end(body);
  } catch (error) {
    const status = error && error.code === "ENOENT" ? 404 : 500;
    response.writeHead(status, { "content-type": "text/plain; charset=utf-8" });
    response.end(status === 404 ? "Not found" : String(error.stack || error));
  }
}

function listen(port) {
  const server = createServer(handleRequest);

  server.on("error", (error) => {
    if (error && error.code === "EADDRINUSE" && port < requestedPort + 50) {
      listen(port + 1);
      return;
    }

    throw error;
  });

  server.listen(port, host, () => {
    console.log(`PromptBoost V2 running at http://${host}:${port}/`);
  });
}

listen(requestedPort);