import assert from "node:assert/strict";
import crypto from "node:crypto";
import fs from "node:fs";
import os from "node:os";
import path from "node:path";
import { pathToFileURL } from "node:url";
import test from "node:test";
import ts from "typescript";

const root = path.resolve(import.meta.dirname, "../../..");
const temporary = fs.mkdtempSync(path.join(os.tmpdir(), "compositor-webgpu-unit-"));

function transpile(sourceName, outputName, replacements = []) {
  const sourcePath = path.join(root, "web/protocol", sourceName);
  const transpiled = ts.transpileModule(fs.readFileSync(sourcePath, "utf8"), {
    compilerOptions: { module: ts.ModuleKind.ES2022, target: ts.ScriptTarget.ES2022 },
    fileName: sourcePath,
    reportDiagnostics: true,
  });
  assert.deepEqual(transpiled.diagnostics, []);
  const output = replacements.reduce((value, [from, to]) => value.replaceAll(from, to), transpiled.outputText);
  fs.writeFileSync(path.join(temporary, outputName), output);
}

transpile("capability-gates.ts", "capability-gates.mjs");
transpile("compositor.ts", "compositor.mjs", [
  ['from "./capability-gates"', 'from "./capability-gates.mjs"'],
]);
const compositor = await import(pathToFileURL(path.join(temporary, "compositor.mjs")));
const golden = JSON.parse(fs.readFileSync(path.join(root, "tests/golden/M11-07/compositor-node-golden.json"), "utf8"));
const sourceColor = [0.125, 0.25, 0.5, 0.75];

function graph(nodeTypes, extraNodes = [], resources = []) {
  const nodes = nodeTypes.map((type, index) => ({
    id: `node:${index}`,
    type,
    name: `${type}:${index}`,
    properties: type === "CONSTANT_COLOR" ? { color: sourceColor } : type === "EXPOSURE" ? { exposure: 1 } : {},
  }));
  return {
    schemaVersion: 1,
    id: `graph:${nodeTypes.join("-")}`,
    name: "M11-07 unit",
    outputNodeId: nodes.at(-1).id,
    nodes: [...nodes, ...extraNodes],
    links: nodes.slice(1).map((node, index) => ({ fromNodeId: nodes[index].id, fromSocket: "Image", toNodeId: node.id, toSocket: "Image" })),
    resources,
  };
}

function repeatedPixel(pixel, count) {
  const result = new Float32Array(count * 4);
  for (let index = 0; index < count; index++) result.set(pixel, index * 4);
  return result;
}

test("M11-07 freezes only nodes with an independent CPU/WebGPU golden", () => {
  assert.deepEqual(compositor.COMPOSITOR_WEBGPU_NODE_ALLOWLIST, golden.allowlist);
  for (const candidate of golden.cases) {
    const value = graph(candidate.nodeTypes);
    const plan = compositor.compileCompositorWebGPUPlan(value);
    assert.deepEqual(plan.instructions.map((instruction) => instruction.type), candidate.nodeTypes);
    const cpu = compositor.executeCompositorGraph(value, new Map(), { width: golden.width, height: golden.height });
    const expected = repeatedPixel(candidate.pixel, golden.width * golden.height);
    assert.deepEqual(cpu.composite.data, expected, candidate.scene);
    assert.equal(crypto.createHash("sha256").update(new Uint8Array(cpu.composite.data.buffer)).digest("hex"), candidate.float32Sha256);
  }
});

test("M11-07 rejects every CPU-only or undeclared node before WebGPU compilation", () => {
  const properties = { ALPHA_OVER: {}, BLUR: { radius: 1 }, IMAGE: { resourceId: "resource:test" }, MIX: { factor: 0.5 }, RENDER_LAYER: { resourceId: "resource:test" }, TRANSFORM: {}, UNSUPPORTED: {}, VIEWER: {} };
  for (const type of golden.blockedNodeTypes) {
    const node = { id: `blocked:${type}`, type, name: type, properties: properties[type], ...(type === "UNSUPPORTED" ? { blenderType: "CompositorNodeGlare" } : {}) };
    const resources = type === "IMAGE" || type === "RENDER_LAYER" ? [{ id: "resource:test", kind: type, sourceId: "image:test" }] : [];
    assert.throws(() => compositor.compileCompositorWebGPUPlan(graph(["CONSTANT_COLOR", "COMPOSITE"], [node], resources)), { code: "COMPOSITOR_NODE_UNSUPPORTED" });
  }
});

test("M11-07 rejects disconnected allowlisted nodes and non-Image links", () => {
  assert.throws(
    () => compositor.compileCompositorWebGPUPlan(graph(["CONSTANT_COLOR", "COMPOSITE"], [{ id: "extra", type: "INVERT", name: "extra", properties: {} }])),
    { code: "COMPOSITOR_GRAPH_INVALID" },
  );
  const malformed = graph(["CONSTANT_COLOR", "EXPOSURE", "COMPOSITE"]);
  malformed.links[0].toSocket = "Value";
  assert.throws(() => compositor.compileCompositorWebGPUPlan(malformed), { code: "COMPOSITOR_GRAPH_INVALID" });
});

test.after(() => fs.rmSync(temporary, { recursive: true, force: true }));