import assert from "node:assert/strict";
import test from "node:test";
import { Mesh } from "../src/Mesh";
import { FXAA } from "../src/PostProcesses/FXAA";
import { PBRMaterial } from "../src/materials/PBRMaterial";
import { Texture } from "../src/materials/Texture";
import {
  bucketDraws,
  createScene,
  detailedMesh,
  forwardPasses,
  latestGraph,
  pbrPipelines,
  renderPipeline,
  testCore,
  triangle,
} from "./scene-helpers";

if (typeof globalThis.ImageBitmap === "undefined")
  Object.defineProperty(globalThis, "ImageBitmap", {
    value: class ImageBitmap {},
  });

test("empty scenes use neutral authored defaults without placeholder geometry", async () => {
  const scene = await createScene();
  const emptyPass = latestGraph(scene).passes.find(
    (pass: any) => pass.id === "forward-empty",
  );

  assert.equal(emptyPass.draw.vertices, 0);
  assert.deepEqual(emptyPass.color[0].clear, [0, 0, 0, 1]);
  assert.deepEqual(Array.from(scene.array("sceneAccent").row(0)), [1, 1, 1, 1]);
});

test("opaque PBR graph has no implicit environment and compacts sparse lights", async () => {
  const scene = await createScene();
  const material = new PBRMaterial(scene);
  await material.ready;
  const mesh = detailedMesh(scene, material);
  await mesh.ready;

  const graph = latestGraph(scene);
  const pipeline = pbrPipelines(graph)[0];
  const forward = forwardPasses(graph)[0];
  const present = renderPipeline(graph, "present");
  const clusters = graph.pipelines.compute.find(
    (candidate: any) => candidate.id === "cluster-lights",
  );

  assert.equal(pipeline.primitive.frontFace, "ccw");
  assert.equal(
    graph.passes.some((pass: any) => pass.id.includes("background")),
    false,
  );
  assert.doesNotMatch(JSON.stringify(graph), /studio/iu);
  assert.deepEqual(forward.color[0].clear, [0, 0, 0, 1]);
  assert.match(pipeline.code, /@interpolate\(flat\) material: u32/u);
  assert.match(pipeline.code, /materials\[input\.material \* 3u\]/u);
  assert.doesNotMatch(pipeline.code, /defaultLight|studioEnvironment/u);
  assert.doesNotMatch(pipeline.code, /0\.4, 0\.7, 0\.6/u);
  assert.match(
    pipeline.code,
    /let ambient = vec3<f32>\(bitcast<f32>\(clusters\[1012\]\)/u,
  );
  assert.match(pipeline.code, /fn directContribution/u);
  assert.match(pipeline.code, /fn directionalContribution/u);
  assert.equal(
    forward.bindings.find((binding: any) => binding.binding === 10)?.resource,
    "directional-lights",
  );

  assert.match(clusters.code, /clusters\[11u \+ pointCount\] = i/u);
  assert.match(clusters.code, /clusters\[512u \+ spotCount\] = i/u);
  assert.match(pipeline.code, /let pointCount = clusters\[10\]/u);
  assert.match(pipeline.code, /pointCount <= 500u/u);
  assert.match(pipeline.code, /arrayLength\(&pointLights\) \/ 2u/u);
  assert.match(
    pipeline.code,
    /let sourceRoughness = clamp\(roughness \+ max\(state\.z/u,
  );
  assert.match(pipeline.code, /let spotCount = clusters\[511\]/u);
  assert.match(pipeline.code, /spotCount <= 500u/u);
});

test("materials with identical shader features share one pipeline", async () => {
  const scene = await createScene();
  const firstMaterial = new PBRMaterial(scene, { roughness: 0.2 });
  const secondMaterial = new PBRMaterial(scene, { roughness: 0.8 });
  await Promise.all([firstMaterial.ready, secondMaterial.ready]);
  const firstMesh = detailedMesh(scene, firstMaterial);
  const secondMesh = detailedMesh(scene, secondMaterial);
  await Promise.all([firstMesh.ready, secondMesh.ready]);

  const graph = latestGraph(scene);
  const draws = bucketDraws(scene, graph);
  assert.equal(pbrPipelines(graph).length, 1);
  // One indirect bucket pass holds both meshes: same pipeline and bind set.
  assert.equal(forwardPasses(graph).length, 1);
  assert.deepEqual(
    draws.map((draw) => draw.firstInstance & 0xffff),
    [firstMesh.id, secondMesh.id],
  );
  assert.deepEqual(
    draws.map((draw) => (draw.firstInstance >>> 16) - 1),
    [firstMaterial.id, secondMaterial.id],
  );
});

test("transmission renders directly into a composited layer with five taps", async () => {
  const scene = await createScene();
  const material = new PBRMaterial(scene, {
    transmission: 0.9,
    thickness: 0.25,
    attenuationDistance: 2,
  });
  await material.ready;
  const mesh = detailedMesh(scene, material);
  await mesh.ready;

  const graph = latestGraph(scene);
  const pipeline = pbrPipelines(graph)[0];
  const present = renderPipeline(graph, "present");
  const presentPass = graph.passes.find((pass: any) => pass.id === "present");

  assert.equal(
    graph.passes.some((pass: any) => pass.id === "scene-color-clear"),
    true,
  );
  const sceneColorClear = graph.passes.find(
    (pass: any) => pass.id === "scene-color-clear",
  );
  assert.equal(sceneColorClear.draw.vertices, 0);
  assert.deepEqual(sceneColorClear.color[0].clear, [0, 0, 0, 1]);
  assert.equal(
    graph.passes.some((pass: any) => pass.id === "copy-scene-color"),
    false,
  );
  assert.equal(
    presentPass.bindings.some(
      (binding: any) => binding.resource === "scene-color",
    ),
    true,
  );
  assert.match(present.code, /textureSample\(scene, sourceSampler/u);
  assert.equal(
    pipeline.code.match(/textureSampleLevel\(sceneColor/g)?.length,
    5,
  );
  assert.match(pipeline.code, /transmitted \*= pow/u);
});

test("clear color is explicit scene data used by empty and forward graphs", async () => {
  const clearColor = [0.03, 0.06, 0.09, 1] as const;
  const scene = await createScene({ clearColor });
  const empty = latestGraph(scene).passes.find(
    (pass: any) => pass.id === "forward-empty",
  );
  assert.deepEqual(empty.color[0].clear, clearColor);

  const material = new PBRMaterial(scene);
  await material.ready;
  const mesh = detailedMesh(scene, material);
  await mesh.ready;

  const graph = latestGraph(scene);
  assert.deepEqual(forwardPasses(graph)[0].color[0].clear, clearColor);
  assert.deepEqual(
    graph.passes.find((pass: any) => pass.id === "present").color[0].clear,
    clearColor,
  );
});

test("post-processing keeps the conservative transmission copy", async () => {
  const scene = await createScene();
  const material = new PBRMaterial(scene, { transmission: 1 });
  await material.ready;
  const mesh = detailedMesh(scene, material);
  await mesh.ready;
  const effect = new FXAA(scene);
  await effect.ready;

  const graph = latestGraph(scene);
  const presentPass = graph.passes.find((pass: any) => pass.id === "present");
  assert.equal(
    graph.passes.some((pass: any) => pass.id === "copy-scene-color"),
    true,
  );
  assert.equal(
    presentPass.bindings.some(
      (binding: any) => binding.resource === "scene-color",
    ),
    false,
  );
  assert.equal(
    graph.passes.some((pass: any) => pass.pipeline.startsWith("post-fxaa-")),
    true,
  );
});

test("PBR generation eliminates inactive features and specializes active ones", async () => {
  const scene = await createScene();
  const textures = Array.from(
    { length: 13 },
    () => new Texture(scene, { size: [1, 1, 1] }),
  );
  await Promise.all(textures.map((texture) => texture.ready));
  const textureOptions = {
    baseColorTexture: textures[0],
    metallicRoughnessTexture: textures[1],
    normalTexture: textures[2],
    emissiveTexture: textures[3],
    occlusionTexture: textures[4],
    transmissionTexture: textures[5],
    thicknessTexture: textures[6],
    clearcoatTexture: textures[7],
    iridescenceTexture: textures[8],
    iridescenceThicknessTexture: textures[9],
    anisotropyTexture: textures[10],
    specularTexture: textures[11],
    specularColorTexture: textures[12],
  };
  const active = new PBRMaterial(scene, {
    ...textureOptions,
    transmission: 1,
    thickness: 0.5,
    attenuationDistance: 2,
    clearcoat: 0.7,
    sheenColor: [0.2, 0.3, 0.4],
    iridescence: 0.8,
    anisotropy: 0.6,
    textureInfos: Array.from({ length: 13 }, (_, slot) => ({
      texCoord: slot === 1 ? 1 : 0,
    })),
  });
  const unlit = new PBRMaterial(scene, { ...textureOptions, flags: 8 });
  await Promise.all([active.ready, unlit.ready]);
  const activeMesh = detailedMesh(scene, active);
  const unlitMesh = detailedMesh(scene, unlit);
  await Promise.all([activeMesh.ready, unlitMesh.ready]);

  const pipelines = pbrPipelines(latestGraph(scene));
  const activeCode = pipelines.find((pipeline: any) =>
    pipeline.code.includes("transmissionAmount"),
  ).code;
  const unlitCode = pipelines.find((pipeline: any) =>
    pipeline.code.includes("color = base.rgb + emissive"),
  ).code;

  for (const binding of [
    "baseTexture",
    "materialTexture",
    "normalTexture",
    "emissiveTexture",
    "occlusionTexture",
    "transmissionTexture",
    "thicknessTexture",
    "clearcoatTexture",
    "iridescenceTexture",
    "iridescenceThicknessTexture",
    "anisotropyTexture",
    "specularTexture",
    "specularColorTexture",
  ])
    assert.match(activeCode, new RegExp(`var ${binding}: texture_2d`));
  assert.match(
    activeCode,
    /textureSample\(baseTexture, materialSampler, input\.uv\)/u,
  );
  assert.match(
    activeCode,
    /textureSample\(materialTexture, materialSampler, input\.uv2\)/u,
  );
  assert.match(activeCode, /let anisotropyAmount/u);
  assert.match(activeCode, /let iridescenceAmount/u);
  assert.match(activeCode, /let clearcoatFresnel/u);
  assert.match(activeCode, /let sheen =/u);
  assert.match(unlitCode, /var baseTexture: texture_2d/u);
  assert.match(unlitCode, /var emissiveTexture: texture_2d/u);
  assert.doesNotMatch(unlitCode, /var normalTexture: texture_2d/u);
  assert.doesNotMatch(unlitCode, /var clearcoatTexture: texture_2d/u);
  assert.doesNotMatch(unlitCode, /let clearcoatFresnel/u);
});

test("alpha blending uses source-over and disables depth writes", async () => {
  const scene = await createScene();
  const material = new PBRMaterial(scene, { flags: 2 });
  await material.ready;
  const mesh = detailedMesh(scene, material);
  await mesh.ready;

  const pipeline = pbrPipelines(latestGraph(scene))[0];
  assert.deepEqual(pipeline.fragment.targets[0].blend, {
    color: {
      srcFactor: "src-alpha",
      dstFactor: "one-minus-src-alpha",
      operation: "add",
    },
    alpha: {
      srcFactor: "one",
      dstFactor: "one-minus-src-alpha",
      operation: "add",
    },
  });
  assert.equal(pipeline.depthStencil.depth_write_enabled, false);
});

test("batchGraphUpdates compiles once for multiple mesh registrations", async () => {
  const scene = await createScene();
  const material = new PBRMaterial(scene);
  await material.ready;
  const before = testCore(scene).graphs.length;

  await scene.batchGraphUpdates(async () => {
    const first = new Mesh(scene, { material, vertexData: triangle });
    const second = new Mesh(scene, { material, vertexData: triangle });
    await Promise.all([first.ready, second.ready]);
  });

  assert.equal(testCore(scene).graphs.length - before, 1);
  assert.equal(forwardPasses(latestGraph(scene)).length, 1);
  assert.equal(bucketDraws(scene, latestGraph(scene)).length, 2);
});

test("draw buckets persist per bind set, zero their inactive tail, and stay blocked while compiling", async () => {
  const scene = await createScene();
  const core = testCore(scene);
  const plain = new PBRMaterial(scene);
  const texture = new Texture(scene, { size: [1, 1, 1] });
  await texture.ready;
  const textured = new PBRMaterial(scene, { baseColorTexture: texture });
  await Promise.all([plain.ready, textured.ready]);
  const meshes: Mesh[] = [];
  for (let index = 0; index < 3; index++)
    meshes.push(await detailedMesh(scene, plain).ready);

  // Three plain meshes fill one bucket; the array grew geometrically from 1 → 2 → 4 rows.
  let graph = latestGraph(scene);
  const bucket = graph.resources.buffers.find((buffer: any) =>
    buffer.id.startsWith("draws-"),
  );
  assert.deepEqual(
    { usage: bucket.usage, sync: bucket.sync },
    { usage: ["indirect"], sync: "manual" },
  );
  assert.equal(core.array(bucket.array).rows, 4);
  assert.equal(bucketDraws(scene, graph).length, 3);
  assert.equal(forwardPasses(graph).length, 1);

  // Moving one mesh to a textured material creates a second bucket; the first keeps two rows
  // and its freed tail is zero (instanceCount 0) so the GPU skips it.
  meshes[1].material = textured;
  await meshes[1].ready;
  await scene.updateRenderGraph();
  graph = latestGraph(scene);
  assert.equal(forwardPasses(graph).length, 2);
  const draws = bucketDraws(scene, graph);
  assert.deepEqual(
    draws.map((draw) => [draw.pass, draw.firstInstance & 0xffff]),
    [
      ["forward-bucket-0", meshes[0].id],
      ["forward-bucket-0", meshes[2].id],
      ["forward-bucket-1", meshes[1].id],
    ],
  );
  assert.deepEqual(
    [...core.array(bucket.array).view.subarray(16, 32)],
    Array(16).fill(0),
  );

  // Back to plain: the second bucket vanishes from the graph, the first regains its row.
  meshes[1].material = plain;
  await meshes[1].ready;
  await scene.updateRenderGraph();
  graph = latestGraph(scene);
  assert.equal(forwardPasses(graph).length, 1);
  assert.equal(bucketDraws(scene, graph).length, 3);

  // A compile that starts after an earlier switch cleared signal 6 re-asserts it before
  // touching bucket rows, so no frame renders the old graph with new bucket contents.
  const signals = core.array("signals").row(0);
  const switchLoadout = core.switchLoadout.bind(core);
  let observed = -1;
  core.switchLoadout = async (id) => {
    await switchLoadout(id);
    signals[6] = 0;
    core.switchLoadout = async (next) => {
      observed = signals[6];
      await switchLoadout(next);
    };
  };
  await Promise.all([scene.updateRenderGraph(), scene.updateRenderGraph()]);
  assert.equal(observed, 1);
  core.switchLoadout = switchLoadout;
});

test("opaque buckets render into the composited layer ahead of transmission", async () => {
  const scene = await createScene();
  const opaque = new PBRMaterial(scene);
  const glass = new PBRMaterial(scene, { transmission: 0.9 });
  await Promise.all([opaque.ready, glass.ready]);
  const solid = detailedMesh(scene, opaque);
  const window = detailedMesh(scene, glass);
  await Promise.all([solid.ready, window.ready]);

  const passes = forwardPasses(latestGraph(scene));
  assert.deepEqual(
    passes.map((pass: any) => [
      pass.id,
      pass.color[0].resource,
      Boolean(pass.indirect),
    ]),
    [
      ["forward-bucket-0", "scene-color", true],
      [
        `forward-${window.id}-${scene.geometry(window.geometryId).indexRow * 4}`,
        "hdr",
        false,
      ],
    ],
  );
});

test("render graph snapshots expose isolated scene-owned declarations", async () => {
  const scene = await createScene();
  const source: any = await scene.getRenderGraph();

  assert.equal(source.id, "scene");
  assert.ok(
    source.resources.buffers.some((buffer: any) => buffer.id === "clusters"),
  );
  source.id = "mutated";
  source.resources.buffers.length = 0;

  const next: any = await scene.getRenderGraph();
  assert.equal(next.id, "scene");
  assert.ok(
    next.resources.buffers.some((buffer: any) => buffer.id === "clusters"),
  );
});

test("serialized render graphs compile into explicitly selectable loadouts", async () => {
  const scene = await createScene();
  const core = testCore(scene);
  const serialized = core.serializedGraphs.at(-1)!;
  const before = core.graphs.length;

  const loadoutId = await scene.compileRenderGraph(serialized);
  await scene.setLoadout(loadoutId);

  assert.equal(core.graphs.length, before + 1);
  assert.equal(loadoutId, `loadout-${before + 1}`);
  assert.equal(core.loadouts.at(-1), loadoutId);
});