'use strict';

const { CameraSwitch } = require('../src/cameraSwitch');

// Testet die Entscheidungslogik von grabSnapshot() ohne Hardware:
// _captureAt (FFmpeg) und _spawnLive sind gemockt.
function makeSwitch(opts = {}) {
  const sw = new CameraSwitch({ id: 'camT', device: '/dev/null', liveSize: '640x480', ...opts });
  sw._captureAt = jest.fn(() => Promise.resolve(Buffer.from([0xFF, 0xD8, 9])));
  sw._spawnLive = jest.fn(() => { sw.proc = {}; sw.state = 'live'; });
  return sw;
}

describe('CameraSwitch.grabSnapshot', () => {
  test('Live läuft (latest gesetzt) → liefert latest, kein Capture', async () => {
    const sw = makeSwitch({ stream: true });
    sw.latest = Buffer.from([1, 2, 3]);
    const f = await sw.grabSnapshot();
    expect(f).toBe(sw.latest);
    expect(sw._captureAt).not.toHaveBeenCalled();
  });

  test('stream:false ohne latest → one-shot _captureAt an liveSize', async () => {
    const sw = makeSwitch({ stream: false });
    sw.latest = null;
    const f = await sw.grabSnapshot();
    expect(Buffer.isBuffer(f)).toBe(true);
    expect(sw._captureAt).toHaveBeenCalledTimes(1);
    expect(sw._captureAt.mock.calls[0][0]).toBe('640x480'); // size = liveSize
    expect(sw._spawnLive).not.toHaveBeenCalled();           // kein Dauer-Stream
  });

  test('Lock wird nach dem one-shot wieder freigegeben', async () => {
    const sw = makeSwitch({ stream: false });
    sw.latest = null;
    await sw.grabSnapshot();
    expect(sw.lock).toBe(false);
    expect(sw.state).toBe('stopped');
  });

  test('belegtes Gerät (lock) → Fehler, kein zweiter Capture', async () => {
    const sw = makeSwitch({ stream: false });
    sw.latest = null;
    sw.lock = true;
    await expect(sw.grabSnapshot()).rejects.toThrow(/belegt/i);
    expect(sw._captureAt).not.toHaveBeenCalled();
  });
});