#!/usr/bin/env node
/**
 * PreToolUse hook: the remote approval gate.
 *
 * Asks the daemon what to do with this tool call. The daemon holds the request open while
 * your phone decides, then answers allow/deny. Every failure path here is fail-open —
 * a daemon that is down, slow, or confused must not be able to block your agent.
 *
 * Denying is the only outcome that changes behaviour, and approving only lets through a
 * call Grok was already about to make. This hook can never introduce a new command.
 */

import { baseUrl, envEnvelope, postJson, readConfig, readStdinJson } from "./glance-lib.mjs";

function allow() {
  process.exit(0);
}

function deny(reason) {
  // Belt and braces: the documented deny signals are a JSON decision on stdout *and*
  // exit code 2. We emit both so a change in precedence cannot silently allow.
  process.stdout.write(
    JSON.stringify({ decision: "deny", reason: reason || "Denied from grok-glance" }),
  );
  process.exit(2);
}

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

// Stay inside the hook timeout declared in hooks/hooks.json (125s).
const waitMs = Math.min(115_000, Number(cfg.approval?.timeoutMs ?? 90_000) + 15_000);

try {
  const { data } = await postJson(`${baseUrl(cfg)}/hook/approve`, payload, waitMs);
  if (data && data.decision === "deny") deny(data.reason);
  allow();
} catch {
  allow();
}