import { spawn } from 'node:child_process';
import path from 'node:path';
import { readPidfile, isProcessAlive } from '@visionl/daemon/dist/pidfile.js';
import { VisionLClient } from '@visionl/core';

const POLL_INTERVAL_MS = 100;
const MAX_WAIT_MS = 3000;

export async function ensureDaemonRunning(port: number): Promise<VisionLClient> {
  const client = new VisionLClient(`http://127.0.0.1:${port}`);

  if (await client.health()) {
    return client;
  }

  const pidInfo = readPidfile();
  if (pidInfo && isProcessAlive(pidInfo.pid)) {
    if (await client.health()) {
      return client;
    }
  }

  // Spawn the browser-enabled daemon entry (boot.js) so that page/content/
  // action routes are registered. Spawning server.js directly would start a
  // browser-less daemon that only serves /health.
  const daemonEntryPath = path.resolve(__dirname, '../../daemon/dist/boot.js');
  spawn('node', [daemonEntryPath], {
    env: { ...process.env, VISIONL_PORT: String(port) },
    stdio: 'ignore',
    detached: true,
  }).unref();

  const startTime = Date.now();
  while (Date.now() - startTime < MAX_WAIT_MS) {
    await new Promise((resolve) => setTimeout(resolve, POLL_INTERVAL_MS));
    if (await client.health()) {
      return client;
    }
  }

  throw new Error('DAEMON_UNREACHABLE');
}