import { env } from "mikro/env";
import { createServer, type ServerResponse } from "mikro/http/server";
import { sleep } from "mikro/sleep";
import { memoryUsage, uptime } from "mikro/sys";
import { wifi } from "mikro/wifi";

const ssid = env.require("WIFI_SSID");
const passphrase = env.require("WIFI_PASSPHRASE");

console.log("Connecting to %s...", ssid);
const connected = await wifi.connect({ ssid, passphrase });
if (!connected.ok) {
  console.error("WiFi connect failed:", connected.error);
} else {
  console.log("Connected. Open http://%s/", connected.value.ip);

  const json = (status: number, value: unknown): ServerResponse => ({
    status,
    headers: { "content-type": "application/json" },
    body: JSON.stringify(value),
  });

  // A short, finite stream. The server handles one request at a time, so a
  // long-lived stream holds the connection until it ends.
  async function* countdown() {
    for (let i = 5; i > 0; i--) {
      yield `data: ${i}\n\n`;
      await sleep(1000);
    }
    yield "data: liftoff\n\n";
  }

  // Routing is left to the app: branch on req.method and the path.
  const server = createServer((req): ServerResponse => {
    if (req.method !== "GET") return json(405, { error: "method not allowed" });
    const path = req.url.split("?")[0];

    if (path === "/") {
      return {
        status: 200,
        headers: { "content-type": "text/html; charset=utf-8" },
        body: `<h1>Mikro.js HTTP server</h1>
<ul>
  <li><a href="/api/status">/api/status</a>: JSON</li>
  <li><a href="/api/echo/hello">/api/echo/&lt;msg&gt;</a>: path param</li>
  <li><a href="/events">/events</a>: server-sent events</li>
</ul>`,
      };
    }

    if (path === "/api/status") {
      const mem = memoryUsage();
      return json(200, { uptime: uptime(), freeHeapBytes: mem.heapTotal - mem.heapUsed });
    }

    if (path?.startsWith("/api/echo/")) {
      return json(200, { echo: decodeURIComponent(path.slice("/api/echo/".length)) });
    }

    if (path === "/events") {
      return { status: 200, headers: { "content-type": "text/event-stream" }, body: countdown() };
    }

    return json(404, { error: "not found" });
  });

  server.listen({ port: 80 }).orPanic("Failed to start HTTP server");
  console.log("Listening on port 80");
}