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

import {
  INK_MASK_FRAME_COUNT,
  INK_MASK_FRAME_MS,
  inkCoverageRadius,
  inkEdgeRadius,
  inkMaskFrameIndex,
} from '../src/lib/inkTransition.ts';

test('ink coverage reaches every viewport corner from the clicked origin', () => {
  const viewport = { width: 1440, height: 900, originX: 1060, originY: 140 };
  const radius = inkCoverageRadius(viewport);
  const farthestCorner = Math.max(
    Math.hypot(viewport.originX, viewport.originY),
    Math.hypot(viewport.width - viewport.originX, viewport.originY),
    Math.hypot(viewport.originX, viewport.height - viewport.originY),
    Math.hypot(viewport.width - viewport.originX, viewport.height - viewport.originY),
  );

  assert.ok(radius > farthestCorner);
});

test('ink edge is organic but remains close enough to guarantee coverage', () => {
  const base = 1000;
  const samples = Array.from({ length: 72 }, (_, index) => inkEdgeRadius(base, index / 72 * Math.PI * 2, 1.8));

  assert.ok(new Set(samples.map((value) => Math.round(value))).size > 20);
  assert.ok(Math.min(...samples) > base * 0.9);
  assert.ok(Math.max(...samples) < base * 1.1);
});

test('ink mask sequence matches the shipped APNG and clamps to its final frame', () => {
  assert.equal(INK_MASK_FRAME_COUNT, 124);
  assert.equal(inkMaskFrameIndex(0), 0);
  assert.equal(inkMaskFrameIndex(INK_MASK_FRAME_MS * 10), 10);
  assert.equal(inkMaskFrameIndex(60_000), 123);
  assert.equal(inkMaskFrameIndex(-100), 0);
});