/** @jest-environment node */
import { GET } from '@/app/(frontend)/release.json/route';
import { readFile } from 'node:fs/promises';

jest.mock('node:fs/promises', () => ({ readFile: jest.fn() }));
const realFetch = global.fetch;
const identity = { sha: 'a'.repeat(40), build_id: 'b'.repeat(32) };
beforeEach(() => {
  jest.mocked(readFile).mockResolvedValue(JSON.stringify(identity));
  global.fetch = jest.fn(async () => Response.json(identity));
});
afterEach(() => { global.fetch = realFetch; jest.resetAllMocks(); });

test('reports immutable file identity and backend identity without caching', async () => {
  const response = await GET();
  expect(response.status).toBe(200);
  expect(response.headers.get('Cache-Control')).toBe('no-store');
  expect(await response.json()).toEqual({ frontend: identity, backend: identity });
  expect(fetch).toHaveBeenCalledWith(expect.stringMatching(/\/api\/release$/), expect.objectContaining({ cache: 'no-store', signal: expect.anything() }));
});

test('missing build metadata cannot pass the release gate', async () => {
  jest.mocked(readFile).mockRejectedValueOnce(new Error('missing file'));
  expect((await GET()).status).toBe(503);
});

test('backend failure cannot pass the release gate', async () => {
  jest.mocked(fetch).mockResolvedValueOnce(new Response('', { status: 503 }));
  expect((await GET()).status).toBe(503);
});