import { mkdtemp, readFile, rm, writeFile } from "node:fs/promises";
import os from "node:os";
import path from "node:path";
import { brotliDecompressSync, gunzipSync } from "node:zlib";
import { afterEach, describe, expect, test } from "vitest";

import { precompressWebAssets, pruneUnreferencedDuplicateCss } from "./precompress-web-assets.mjs";

const temporaryDirectories = [];

afterEach(async () => {
  await Promise.all(temporaryDirectories.splice(0).map((directory) => rm(directory, { force: true, recursive: true })));
});

describe("precompressWebAssets", () => {
  test("writes deterministic sidecars only for worthwhile static text assets", async () => {
    const directory = await mkdtemp(path.join(os.tmpdir(), "hivegrid-precompress-"));
    temporaryDirectories.push(directory);
    const source = Buffer.from("const message = 'compressible';\n".repeat(500));
    const jsPath = path.join(directory, "app.js");
    await Promise.all([writeFile(jsPath, source), writeFile(path.join(directory, "small.json"), "{}")]);

    const report = await precompressWebAssets(directory);
    expect(report).toEqual({ considered: 1, brotliWritten: 1, gzipWritten: 1 });
    expect(brotliDecompressSync(await readFile(`${jsPath}.br`))).toEqual(source);
    expect(gunzipSync(await readFile(`${jsPath}.gz`))).toEqual(source);
    await expect(readFile(path.join(directory, "small.json.br"))).rejects.toMatchObject({ code: "ENOENT" });
  });

  test("removes only byte-identical unreferenced React Router server CSS duplicates", async () => {
    const directory = await mkdtemp(path.join(os.tmpdir(), "hivegrid-css-prune-"));
    temporaryDirectories.push(directory);
    const duplicateCss = Buffer.from(".root { color: green; }".repeat(100));
    await Promise.all([
      writeFile(path.join(directory, "root-hash.css"), duplicateCss),
      writeFile(path.join(directory, "server-build-hash.css"), duplicateCss),
      writeFile(path.join(directory, "manifest.js"), 'window.assets=["root-hash.css"];'),
    ]);

    await expect(pruneUnreferencedDuplicateCss(directory)).resolves.toEqual({
      removed: 1,
      bytesRemoved: duplicateCss.length,
    });
    await expect(readFile(path.join(directory, "server-build-hash.css"))).rejects.toMatchObject({ code: "ENOENT" });
    await expect(readFile(path.join(directory, "root-hash.css"))).resolves.toEqual(duplicateCss);
  });

  test("keeps referenced or non-identical server CSS assets", async () => {
    const directory = await mkdtemp(path.join(os.tmpdir(), "hivegrid-css-prune-"));
    temporaryDirectories.push(directory);
    await Promise.all([
      writeFile(path.join(directory, "root-hash.css"), ".root { color: green; }"),
      writeFile(path.join(directory, "server-build-referenced.css"), ".root { color: green; }"),
      writeFile(path.join(directory, "server-build-distinct.css"), ".root { color: red; }"),
      writeFile(path.join(directory, "manifest.js"), 'window.assets=["server-build-referenced.css"];'),
    ]);

    await expect(pruneUnreferencedDuplicateCss(directory)).resolves.toEqual({ removed: 0, bytesRemoved: 0 });
    await expect(readFile(path.join(directory, "server-build-referenced.css"))).resolves.toBeTruthy();
    await expect(readFile(path.join(directory, "server-build-distinct.css"))).resolves.toBeTruthy();
  });
});