SlabUploader/frontend/src/png/inventory.test.ts

import { test } from 'node:test';
import assert from 'node:assert/strict';
import { composeInventoryFrame } from './inventory.ts';
import type { Mask, Source } from '../capture/capture.types';

const makePhoto = (w: number, h: number, paint: (x: number, y: number) => [number, number, number, number] = () => [255, 255, 255, 255]) => {
  const rgba = new Uint8Array(w * h * 4);
  for (let y = 0; y < h; y++) {
    for (let x = 0; x < w; x++) {
      const [r, g, b, a] = paint(x, y);
      const i = (y * w + x) * 4;
      rgba[i] = r; rgba[i + 1] = g; rgba[i + 2] = b; rgba[i + 3] = a;
    }
  }
  return { width: w, height: h, rgba };
};

const maskFor = (bitset: Uint8Array, slabBounds: Mask['slabBounds']): Pick<Mask, 'bitset' | 'slabBounds'> =>
  ({ bitset, slabBounds });

test('alpha contract: removed pixels transparent, slab pixels keep RGB at alpha 255', () => {
  const W = 8, H = 8;
  const bitset = new Uint8Array(W * H);
  for (let y = 1; y < 5; y++) for (let x = 1; x < 5; x++) bitset[y * W + x] = 1;
  bitset[2 * W + 2] = 0;
  bitset[3 * W + 3] = 0;
  const SLAB = [200, 40, 20, 255] as const;
  const SHEET = [0, 255, 0, 255] as const;
  const src = makePhoto(W, H, (x, y) => (bitset[y * W + x] === 1 ? [...SLAB] : [...SHEET]));
  const source: Pick<Source, 'widthPx' | 'heightPx'> = { widthPx: W, heightPx: H };
  const out = composeInventoryFrame(src, maskFor(bitset, { x: 1, y: 1, w: 4, h: 4 }), source);

  assert.equal(out.sourceBelowFloor, true);
  assert.ok(out.width < 800, 'undersized source stays small');

  let opaque = 0;
  let transparent = 0;
  for (let i = 0; i < out.rgba.length; i += 4) {
    const a = out.rgba[i + 3];
    if (a === 0) {
      transparent++;
      assert.equal(out.rgba[i], 0);
      assert.equal(out.rgba[i + 1], 0);
      assert.equal(out.rgba[i + 2], 0);
      continue;
    }
    opaque++;
    assert.equal(a, 255);
    assert.deepEqual(
      [out.rgba[i], out.rgba[i + 1], out.rgba[i + 2]],
      [SLAB[0], SLAB[1], SLAB[2]],
      'opaque pixel must be slab RGB, never sheet green',
    );
  }
  assert.ok(opaque > 0, 'slab pixels are opaque');
  assert.ok(transparent > 0, 'frame has transparent pixels');
});

test('3:4 frame at the floor: 2000×1800 slab → 800×1067', () => {
  const source: Pick<Source, 'widthPx' | 'heightPx'> = { widthPx: 2000, heightPx: 1800 };
  const bitset = new Uint8Array(source.widthPx * source.heightPx).fill(1);
  const out = composeInventoryFrame(
    makePhoto(source.widthPx, source.heightPx),
    maskFor(bitset, { x: 0, y: 0, w: 2000, h: 1800 }),
    source,
  );
  assert.equal(out.width, 800);
  assert.equal(out.height, 1067);
  assert.equal(out.sourceBelowFloor, false);
});

test('mid-band: slab shorter side 1000 (between 800 and 1600) → at floor, not belowFloor', () => {
  const source: Pick<Source, 'widthPx' | 'heightPx'> = { widthPx: 1200, heightPx: 1000 };
  const bitset = new Uint8Array(source.widthPx * source.heightPx).fill(1);
  const out = composeInventoryFrame(
    makePhoto(source.widthPx, source.heightPx),
    maskFor(bitset, { x: 0, y: 0, w: 1200, h: 1000 }),
    source,
  );
  assert.equal(out.sourceBelowFloor, false);
  assert.equal(out.width, 800);
});

test('80% fill: limiting dimension maps to 0.8 × frame side', () => {
  const source: Pick<Source, 'widthPx' | 'heightPx'> = { widthPx: 2200, heightPx: 2000 };
  const bitset = new Uint8Array(source.widthPx * source.heightPx).fill(1);
  const out = composeInventoryFrame(
    makePhoto(source.widthPx, source.heightPx),
    maskFor(bitset, { x: 100, y: 100, w: 2000, h: 1800 }),
    source,
  );
  let minx = out.width, maxx = -1, miny = out.height, maxy = -1;
  for (let y = 0; y < out.height; y++) {
    for (let x = 0; x < out.width; x++) {
      if (out.rgba[(y * out.width + x) * 4 + 3] !== 0) {
        if (x < minx) minx = x;
        if (x > maxx) maxx = x;
        if (y < miny) miny = y;
        if (y > maxy) maxy = y;
      }
    }
  }
  const xs = [minx, maxx], ys = [miny, maxy];
  const wExtent = Math.max(...xs) - Math.min(...xs) + 1;
  const hExtent = Math.max(...ys) - Math.min(...ys) + 1;
  assert.ok(Math.abs(wExtent - 640) <= 2, `width extent ${wExtent} ≈ 640 (0.8×800)`);
  assert.ok(Math.abs(hExtent - 576) <= 2, `height extent ${hExtent} ≈ 576 (1800×0.32)`);
});

test('belowFloor: small slab → sourceBelowFloor, outW capped at floor (no upscale)', () => {
  const source: Pick<Source, 'widthPx' | 'heightPx'> = { widthPx: 900, heightPx: 700 };
  const bitset = new Uint8Array(source.widthPx * source.heightPx).fill(1);
  const out = composeInventoryFrame(
    makePhoto(source.widthPx, source.heightPx),
    maskFor(bitset, { x: 0, y: 0, w: 900, h: 700 }),
    source,
  );
  assert.equal(out.sourceBelowFloor, true);
  assert.ok(out.width <= 800, `outW ${out.width} must not exceed the floor`);
});