#!/usr/bin/env node
/**
 * SessionStart hook: make sure the glance daemon is running, then record the event.
 *
 * This is the only hook that spawns anything. It always exits 0 — a monitoring
 * dashboard must never be the reason a Grok Build session fails to start.
 */

import fs from "node:fs";
import path from "node:path";
import { spawn } from "node:child_process";
import {
  PLUGIN_ROOT,
  baseUrl,
  envEnvelope,
  glanceHome,
  hookHeaders,
  isDaemonUp,
  postJson,
  readConfig,
  readStdinJson,
  sleep,
} from "./glance-lib.mjs";

const SERVER_ENTRY = path.join(PLUGIN_ROOT, "dist", "server", "index.js");

async function ensureDaemon(cfg) {
  if (await isDaemonUp(cfg)) return true;

  if (!fs.existsSync(SERVER_ENTRY)) {
    // dist/ ships with the plugin, so this means an incomplete checkout. Say so once, on
    // stderr, where it is recorded but harmless — a hook must never fail a session.
    process.stderr.write(
      `[grok-glance] dist/ is missing - run \`npm install && npm run build\` in ${PLUGIN_ROOT}\n`,
    );
    return false;
  }

  const home = glanceHome();
  fs.mkdirSync(home, { recursive: true });
  const logFd = fs.openSync(path.join(home, "daemon.log"), "a");

  const child = spawn(process.execPath, [SERVER_ENTRY], {
    detached: true,
    stdio: ["ignore", logFd, logFd],
    env: { ...process.env, GLANCE_STARTED_BY: "hook" },
  });
  child.unref();

  // Give it a moment to bind before the first http hook fires.
  for (let i = 0; i < 40; i++) {
    await sleep(200);
    if (await isDaemonUp(cfg, 300)) return true;
  }
  return false;
}

const payload = envEnvelope(await readStdinJson());
const cfg = readConfig();

try {
  const up = await ensureDaemon(cfg);
  if (up) {
    // hookHeaders() is read here, not at import time: on a first-ever run the daemon we just
    // spawned is what created hook.secret.
    await postJson(`${baseUrl(cfg)}/hook/record`, payload, 2500, hookHeaders());
  }
} catch {
  // Fail open, always.
}

process.exit(0);