import assert from "node:assert/strict";
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 repoRoot = path.resolve(import.meta.dirname, "../../..");
const temporary = fs.mkdtempSync(path.join(os.tmpdir(), "paint-depth-visibility-unit-"));

function transpile(sourceName, outputName, transform = (source) => source) {
  const sourcePath = path.join(repoRoot, "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, []);
  fs.writeFileSync(path.join(temporary, outputName), transform(transpiled.outputText));
}

transpile("paint.ts", "paint.mjs");
transpile("paint-depth-visibility.ts", "paint-depth-visibility.mjs", (source) => source.replace('from "./paint"', 'from "./paint.mjs"'));
const visibility = await import(pathToFileURL(path.join(temporary, "paint-depth-visibility.mjs")));

const request = {
  schemaVersion: 1,
  objectId: "object:Paint",
  meshId: "mesh:Paint",
  revision: 7,
  vertexIndices: [6, 2, 4],
};

test("M9-09 binds GPU depth visibility to stable vertex identities and Main revision", () => {
  const parsed = visibility.validatePaintDepthVisibilityRequest(request, 7);
  assert.deepEqual(parsed.vertexIndices, [2, 4, 6]);
  const result = visibility.validatePaintDepthVisibilityResult({
    ...parsed,
    backend: "MAIN_THREAD_WEBGL2",
    source: "GPU_RGBA_DEPTH_READBACK",
    width: 64,
    height: 32,
    depthReadbackBytes: 64 * 32 * 4,
    occluderPixelCount: 512,
    visibleVertexIndices: [2, 6],
  }, parsed);
  assert.deepEqual(result.visibleVertexIndices, [2, 6]);
  assert.equal(result.source, "GPU_RGBA_DEPTH_READBACK");
});

test("M9-09 fails closed on stale, forged, duplicate and over-budget depth samples", () => {
  assert.throws(() => visibility.validatePaintDepthVisibilityRequest(request, 8), (error) => error.code === "REVISION_CONFLICT");
  assert.throws(() => visibility.validatePaintDepthVisibilityRequest({ ...request, objectId: "mesh:Paint" }, 7), (error) => error.code === "PAINT_SCHEMA_INVALID");
  assert.throws(() => visibility.validatePaintDepthVisibilityRequest({ ...request, vertexIndices: [2, 2] }, 7), (error) => error.code === "PAINT_SCHEMA_INVALID");
  assert.throws(() => visibility.validatePaintDepthVisibilityRequest({ ...request, undeclared: true }, 7), (error) => error.code === "PAINT_SCHEMA_INVALID");
  assert.throws(
    () => visibility.validatePaintDepthVisibilityRequest({ ...request, vertexIndices: Array.from({ length: 100_001 }, (_, index) => index) }, 7),
    (error) => error.code === "PAINT_BUDGET_EXCEEDED",
  );
});

test("M9-09 rejects result drift and accepts a verified empty visible set", () => {
  const parsed = visibility.validatePaintDepthVisibilityRequest(request, 7);
  const base = {
    ...parsed,
    backend: "OFFSCREEN_WEBGL2",
    source: "GPU_RGBA_DEPTH_READBACK",
    width: 32,
    height: 32,
    depthReadbackBytes: 4096,
    occluderPixelCount: 128,
    visibleVertexIndices: [],
  };
  assert.deepEqual(visibility.validatePaintDepthVisibilityResult(base, parsed).visibleVertexIndices, []);
  assert.throws(() => visibility.validatePaintDepthVisibilityResult({ ...base, visibleVertexIndices: [99] }, parsed), (error) => error.code === "PAINT_SCHEMA_INVALID");
  assert.throws(() => visibility.validatePaintDepthVisibilityResult({ ...base, depthReadbackBytes: 4095 }, parsed), (error) => error.code === "PAINT_BUDGET_EXCEEDED");
  assert.throws(() => visibility.validatePaintDepthVisibilityResult({ ...base, source: "CPU_RAYCAST" }, parsed), (error) => error.code === "PAINT_SCHEMA_INVALID");
});