import { describe, it, expect, vi, afterEach } from 'vitest';
import { loadConfig, DEFAULT_RENDER } from './config';

function mockFetch(body: unknown, ok = true) {
  vi.stubGlobal('fetch', vi.fn().mockResolvedValue({
    ok,
    json: () => Promise.resolve(body),
  }));
}

afterEach(() => vi.unstubAllGlobals());

describe('loadConfig', () => {
  it('loads stream URL and fills render defaults', async () => {
    mockFetch({ streamUrl: 'http://cam/stream' });
    const cfg = await loadConfig('config.json');
    expect(cfg.streamUrl).toBe('http://cam/stream');
    expect(cfg.renderDefaults).toEqual(DEFAULT_RENDER);
    expect(cfg.calibration).toBeNull();
  });

  it('keeps a valid calibration', async () => {
    const calibration = {
      imagePoints: [[0, 0], [1, 0], [1, 1], [0, 1]],
      machinePoints: [[0, 0], [1, 0], [1, 1], [0, 1]],
      homography: [1, 0, 0, 0, 1, 0, 0, 0, 1],
    };
    mockFetch({ streamUrl: 'x', calibration });
    const cfg = await loadConfig('config.json');
    expect(cfg.calibration).toEqual(calibration);
  });

  it('drops a malformed calibration to null', async () => {
    mockFetch({ streamUrl: 'x', calibration: { homography: [1, 2, 3] } });
    const cfg = await loadConfig('config.json');
    expect(cfg.calibration).toBeNull();
  });

  it('throws when the request fails', async () => {
    mockFetch({}, false);
    await expect(loadConfig('config.json')).rejects.toThrow();
  });

  it('ignores malformed renderDefaults fields, keeping defaults and dropping extras', async () => {
    mockFetch({ streamUrl: 'x', renderDefaults: { lineWidth: 'thick', cutColor: '#abc', bogus: true } });
    const cfg = await loadConfig('config.json');
    expect(cfg.renderDefaults.cutColor).toBe('#abc'); // valid string kept
    expect(cfg.renderDefaults.lineWidth).toBe(DEFAULT_RENDER.lineWidth); // invalid number → default
    expect(cfg.renderDefaults.rapidColor).toBe(DEFAULT_RENDER.rapidColor); // missing → default
    expect(cfg.renderDefaults).not.toHaveProperty('bogus'); // extra key dropped
  });

  it('rejects a calibration whose homography contains NaN', async () => {
    const calibration = {
      imagePoints: [[0, 0], [1, 0], [1, 1], [0, 1]],
      machinePoints: [[0, 0], [1, 0], [1, 1], [0, 1]],
      homography: [1, 0, 0, 0, 1, 0, 0, 0, NaN],
    };
    mockFetch({ streamUrl: 'x', calibration });
    const cfg = await loadConfig('config.json');
    expect(cfg.calibration).toBeNull();
  });
});