import { setTestTimeScale } from '@/lib/sim/engine';

// TEST-ONLY hook (v0.52.0, ISS-117) — lets the e2e suite override the effective time scale now
// that there are no player-facing controls; without it every spec would run at the fixed world
// rate and a cross-Europe leg would take hours of real time. Disabled unless FLIGHT_TEST_HOOKS=1
// (set in docker-compose.yml for the e2e instance only); every other deployment 404s here.
// Sibling of /api/test/set-health — same gate, same conventions.
//
// POST /api/test/set-timescale
//   body { timeScale: number } — a finite number in [1, 100_000] (400 otherwise).
//   Ticks first so the write lands on current game state, under the sim lock.
//   Returns { clockMs, timeScale } — the new effective scale for test assertions.

export async function POST(req: Request) {
  if (process.env.FLIGHT_TEST_HOOKS !== '1') {
    return Response.json({ error: 'test hooks disabled' }, { status: 404 });
  }

  let body: unknown = {};
  try {
    const text = await req.text();
    body = text ? JSON.parse(text) : {};
  } catch {
    return Response.json({ error: 'invalid JSON body' }, { status: 400 });
  }
  if (typeof body !== 'object' || body === null || Array.isArray(body)) {
    return Response.json({ error: 'body must be a JSON object' }, { status: 400 });
  }
  const input = body as Record<string, unknown>;
  for (const key of Object.keys(input)) {
    if (key !== 'timeScale') {
      return Response.json({ error: `unknown field "${key}"` }, { status: 400 });
    }
  }
  const timeScale = input.timeScale;
  if (typeof timeScale !== 'number' || !Number.isFinite(timeScale) || timeScale < 1 || timeScale > 100_000) {
    return Response.json({ error: 'timeScale must be a finite number in [1, 100000]' }, { status: 400 });
  }

  try {
    const row = await setTestTimeScale(timeScale);
    return Response.json({ clockMs: row.clockMs, timeScale: row.timeScale });
  } catch (err) {
    console.error('test hook failed', err);
    return Response.json({ error: 'test hook failed' }, { status: 500 });
  }
}