import { describe, expect, it } from 'vitest';
import * as THREE from 'three';
import { applyMapTransform } from './cardMaterial';

describe('applyMapTransform', () => {
  it('injects the repeat/offset uniforms and UV transform into the shader', () => {
    const mat = new THREE.MeshStandardMaterial();
    applyMapTransform(mat, new THREE.Vector2(0.5, 0.25), new THREE.Vector2(0.1, 0.2));

    expect(mat.onBeforeCompile).toBeTypeOf('function');

    const shader = {
      uniforms: {} as Record<string, { value: unknown }>,
      vertexShader: '#include <uv_vertex>\nvoid main() {}',
    };
    mat.onBeforeCompile!(shader as never, {} as never);

    // Uniforms are copied, so the caller's vectors stay reusable.
    expect(shader.uniforms.uMapRepeat!.value).toEqual(new THREE.Vector2(0.5, 0.25));
    expect(shader.uniforms.uMapOffset!.value).toEqual(new THREE.Vector2(0.1, 0.2));
    // The override is injected right after the chunk include, which stays in
    // place (it declares `vMapUv`/`uv`).
    expect(shader.vertexShader).toContain('#include <uv_vertex>\n\tvMapUv = uv * uMapRepeat + uMapOffset;');
  });

  it('copies the vectors so later mutation of the inputs has no effect', () => {
    const mat = new THREE.MeshStandardMaterial();
    const repeat = new THREE.Vector2(1, 1);
    const offset = new THREE.Vector2(0, 0);
    applyMapTransform(mat, repeat, offset);

    repeat.set(9, 9);
    offset.set(9, 9);

    const shader = { uniforms: {} as Record<string, { value: unknown }>, vertexShader: '' };
    mat.onBeforeCompile!(shader as never, {} as never);
    expect(shader.uniforms.uMapRepeat!.value).toEqual(new THREE.Vector2(1, 1));
    expect(shader.uniforms.uMapOffset!.value).toEqual(new THREE.Vector2(0, 0));
  });
});