import test from 'node:test';
import assert from 'node:assert/strict';

import {
  analyzeFrameLuma,
  buildThumbnailCandidateTimes
} from '../public/modules/thumbnail-utils.js';

test('buildThumbnailCandidateTimes prefers early seconds and appends a bounded fallback', () => {
  assert.deepEqual(buildThumbnailCandidateTimes(0), [0.15]);
  assert.deepEqual(buildThumbnailCandidateTimes(1.2), [0.15, 0.5, 1, 1.15]);
  assert.deepEqual(buildThumbnailCandidateTimes(6), [0.15, 0.5, 1, 2, 3.5, 5, 5.95]);
});

test('analyzeFrameLuma marks near-black frames as black and bright frames as usable', () => {
  const blackFrame = new Uint8ClampedArray(64 * 4).fill(0);
  for (let index = 3; index < blackFrame.length; index += 4) {
    blackFrame[index] = 255;
  }

  const brightFrame = new Uint8ClampedArray(64 * 4);
  for (let index = 0; index < brightFrame.length; index += 4) {
    brightFrame[index] = 200;
    brightFrame[index + 1] = 180;
    brightFrame[index + 2] = 120;
    brightFrame[index + 3] = 255;
  }

  const blackAnalysis = analyzeFrameLuma(blackFrame, {
    stride: 1
  });
  const brightAnalysis = analyzeFrameLuma(brightFrame, {
    stride: 1
  });

  assert.equal(blackAnalysis.isBlackFrame, true);
  assert.equal(brightAnalysis.isBlackFrame, false);
  assert.ok(blackAnalysis.darkRatio > brightAnalysis.darkRatio);
  assert.ok(brightAnalysis.averageLuma > blackAnalysis.averageLuma);
});