import crypto from "node:crypto";
import fs from "node:fs";
import os from "node:os";
import path from "node:path";
import { spawnSync } from "node:child_process";
import { expect, test, type Page } from "@playwright/test";

const root = path.resolve(import.meta.dirname, "../../..");
const fixtureRoot = path.join(root, "tests/files/web/m12_obj_multi_v1");
const sourceObj = fs.readFileSync(path.join(fixtureRoot, "multi-object.obj"));
const sourceMtl = fs.readFileSync(path.join(fixtureRoot, "multi-object.mtl"));
const texture = fs.readFileSync(path.join(fixtureRoot, "m12_obj_texture.png"));
const reportPath = path.join(root, "tests/golden/M12-07C/web-roundtrip-report.json");
const sha256 = (bytes: Uint8Array | Buffer | string) => crypto.createHash("sha256").update(bytes).digest("hex");

async function runBrowserRoundtrip(page: Page, textureAssets: string[]) {
  return page.evaluate(async (input: { obj: number[]; mtl: number[]; textureAssets: string[] }) => new Promise<any>((resolve, reject) => {
    const worker = new Worker("/src/workers/obj-roundtrip-test.worker.ts", { type: "module" });
    worker.onmessage = (event: MessageEvent<any>) => { worker.terminate(); resolve(event.data); };
    worker.onerror = (event) => { worker.terminate(); reject(new Error(event.message)); };
    const obj = Uint8Array.from(input.obj).buffer;
    const mtl = Uint8Array.from(input.mtl).buffer;
    worker.postMessage({ obj, mtl, textureAssets: input.textureAssets }, [obj, mtl]);
  }), { obj: Array.from(sourceObj), mtl: Array.from(sourceMtl), textureAssets });
}

test("M12-07C round-trips a Web OBJ through desktop Blender and reports texture loss", async ({ page }) => {
  await page.goto("/");
  const bound = await runBrowserRoundtrip(page, ["m12_obj_texture.png"]);
  const missing = await runBrowserRoundtrip(page, []);
  expect(bound.ok).toBe(true);
  expect(bound.lossReport).toEqual({ schemaVersion: 1, operation: "OBJ_EXPORT_LOSS_REPORT", canRoundTrip: true, warningCount: 0, warnings: [] });
  expect(missing.lossReport.warnings.map((warning: { code: string }) => warning.code)).toEqual(["OBJ_TEXTURE_ORIGIN_UNRESOLVED", "OBJ_TEXTURE_ORIGIN_UNRESOLVED"]);

  const temporary = fs.mkdtempSync(path.join(os.tmpdir(), "m12-07c-web-obj-"));
  try {
    const webObjPath = path.join(temporary, "web-output.obj");
    const webMtlPath = path.join(temporary, "single-mesh.mtl");
    fs.writeFileSync(webObjPath, bound.obj, "utf8");
    fs.writeFileSync(webMtlPath, bound.mtl, "utf8");
    fs.writeFileSync(path.join(temporary, "m12_obj_texture.png"), texture);
    const desktopReportPath = path.join(temporary, "desktop-report.json");
    const blender = process.env.BLENDER_BIN ?? path.join(root, "build_blender_5.2.0/bin/blender");
    const result = spawnSync(blender, ["-b", "--factory-startup", "--python", path.join(root, "tools/web/check-obj-web-roundtrip.py"), "--", webObjPath, desktopReportPath], { cwd: root, encoding: "utf8", maxBuffer: 20 * 1024 * 1024 });
    expect(result.status, `${result.stdout}\n${result.stderr}`).toBe(0);
    const desktop = JSON.parse(fs.readFileSync(desktopReportPath, "utf8"));
    const report = {
      schemaVersion: 1,
      task: "M12-07C",
      operation: "WEB_OBJ_TO_DESKTOP_ROUNDTRIP",
      source: { objSha256: sha256(sourceObj), mtlSha256: sha256(sourceMtl), textureSha256: sha256(texture) },
      browser: {
        imported: {
          schemaVersion: bound.imported.schemaVersion,
          objectCount: bound.imported.objects.length,
          positionCount: bound.imported.positions.length,
          texcoordCount: bound.imported.texcoords.length,
          normalCount: bound.imported.normals.length,
          faceCount: bound.imported.faces.length,
          materialCount: bound.imported.materials.length,
        },
        outputObjSha256: sha256(Buffer.from(bound.obj)),
        outputMtlSha256: sha256(Buffer.from(bound.mtl)),
        lossReport: bound.lossReport,
        missingTextureLoss: missing.lossReport,
      },
      desktop,
      comparisons: {
        objectCountExact: desktop.objectCount === bound.imported.objects.length,
        triangleCountExact: desktop.objects.reduce((sum: number, object: { triangleCount: number }) => sum + object.triangleCount, 0) === bound.imported.faces.length,
        uvLayerPresent: desktop.objects.every((object: { uvLayers: string[] }) => object.uvLayers.includes("UVMap")),
        materialPresent: desktop.objects.every((object: { materials: string[] }) => object.materials.length === 1),
      },
      nextTask: "M12-07D",
    };
    if (process.env.UPDATE_OBJ_ROUNDTRIP === "1") {
      fs.mkdirSync(path.dirname(reportPath), { recursive: true });
      fs.writeFileSync(reportPath, JSON.stringify(report, null, 2) + "\n");
    }
    const expected = JSON.parse(fs.readFileSync(reportPath, "utf8"));
    expect(report).toEqual(expected);
    expect(report.comparisons).toEqual({ objectCountExact: true, triangleCountExact: true, uvLayerPresent: true, materialPresent: true });
  }
  finally {
    fs.rmSync(temporary, { recursive: true, force: true });
  }
});