import { createServer } from "node:http";
import { readFile, stat } from "node:fs/promises";
import { watch } from "node:fs";
import { resolve, extname, sep } from "node:path";
import { fileURLToPath } from "node:url";
import { build, root } from "./build.mjs";
const mime = {
  ".json": "application/json; charset=utf-8",
  ".txt": "text/plain; charset=utf-8",
  ".html": "text/html; charset=utf-8",
  ".css": "text/css",
  ".js": "text/javascript",
  ".mjs": "text/javascript",
  ".svg": "image/svg+xml",
  ".webp": "image/webp",
  ".woff2": "font/woff2",
  ".png": "image/png",
};
export async function startPreview({ port = 4174, rebuild = true } = {}) {
  if (rebuild) await build();
  const directory = resolve(root, "dist");
  const server = createServer(async (req, res) => {
    try {
      const path = decodeURIComponent(
        new URL(req.url, "http://localhost").pathname,
      );
      let file = resolve(directory, "." + path);
      if (file !== directory && !file.startsWith(directory + sep)) {
        res.writeHead(403).end();
        return;
      }
      if ((await stat(file)).isDirectory()) file = resolve(file, "index.html");
      const body = await readFile(file);
      res
        .writeHead(200, {
          "Content-Type": mime[extname(file)] || "application/octet-stream",
          "Cache-Control": "no-store",
        })
        .end(body);
    } catch (error) {
      const status =
        error.code === "ENOENT" ? 404 : error instanceof URIError ? 400 : 500;
      if (status === 500) console.error(error);
      res
        .writeHead(status)
        .end(status === 404 ? "Not found" : "Unable to serve this file");
    }
  });
  await new Promise((done, reject) => {
    server.once("error", reject);
    server.listen(port, "127.0.0.1", done);
  });
  return {
    url: `http://127.0.0.1:${server.address().port}/`,
    close: () =>
      new Promise((done, reject) =>
        server.close((error) => (error ? reject(error) : done())),
      ),
  };
}
if (
  process.argv[1] &&
  resolve(process.argv[1]) === fileURLToPath(import.meta.url)
) {
  const app = await startPreview({ port: Number(process.env.PORT || 4174) });
  console.log(`Preview: ${app.url}`);
  let watcher,
    timer,
    building = Promise.resolve();
  if (process.argv.includes("--watch"))
    watcher = watch(resolve(root, "src"), { recursive: true }, () => {
      clearTimeout(timer);
      timer = setTimeout(() => {
        building = building
          .then(() => build())
          .then(() => console.log("Rebuilt. Refresh the browser."))
          .catch(console.error);
      }, 100);
    });
  async function close() {
    clearTimeout(timer);
    watcher?.close();
    await building;
    await app.close();
  }
  process.once("SIGINT", close);
  process.once("SIGTERM", close);
}