import { spawn } from "node:child_process";
import net from "node:net";

export function isPortFree(host: string, port: number): Promise<boolean> {
  return new Promise((resolve) => {
    const socket = net.connect({ host, port, timeout: 500 });
    socket.once("connect", () => {
      socket.destroy();
      resolve(false);
    });
    socket.once("timeout", () => {
      socket.destroy();
      resolve(true);
    });
    socket.once("error", () => {
      resolve(true);
    });
  });
}

export async function waitUntilReady(
  url: string,
  timeoutMs: number,
  intervalMs = 400,
): Promise<boolean> {
  const deadline = Date.now() + timeoutMs;
  while (Date.now() < deadline) {
    try {
      const response = await fetch(url, { signal: AbortSignal.timeout(1500) });
      if (response.status === 200) return true;
    } catch {
      // not ready yet
    }
    await new Promise((resolve) => setTimeout(resolve, intervalMs));
  }
  return false;
}

/** Single-shot check (not a poll loop, unlike `waitUntilReady`) for whether a triggershell server
 * is already listening at `url` - used to decide whether `run` can go through the REST/WS API. */
export async function isServerReachable(url: string): Promise<boolean> {
  try {
    const response = await fetch(`${url}/api/healthz`, {
      signal: AbortSignal.timeout(1000),
    });
    return response.status === 200;
  } catch {
    return false;
  }
}

export function openBrowser(url: string): void {
  const command =
    process.platform === "darwin"
      ? "open"
      : process.platform === "win32"
        ? "start"
        : "xdg-open";
  const args = process.platform === "win32" ? ["", url] : [url];
  try {
    spawn(command, args, {
      detached: true,
      stdio: "ignore",
      shell: process.platform === "win32",
    }).unref();
  } catch {
    // best-effort - not fatal if no browser opener is available
  }
}