/**
 * Beyond our own code: after Chromium renders a document, nothing it left on disk may contain that document. Chromium
 * keeps a profile, a cache and crash data in temp folders; this searches all of them for a unique marker while the
 * browser is still running, and again after it closes. (Review follow-up, 2026-11-07.)
 */
import { existsSync, readdirSync, readFileSync, statSync } from "node:fs";
import { tmpdir } from "node:os";
import path from "node:path";
import { afterAll, describe, expect, it } from "vitest";
import { Renderer } from "@pagenull/renderer";

const renderer = new Renderer({ concurrency: 1 });
afterAll(() => renderer.close());

/** Every file under `dir` (skipping anything unreadable), up to a sane size. */
function files(dir: string, out: string[] = []): string[] {
  let entries: string[] = [];
  try {
    entries = readdirSync(dir);
  } catch {
    return out;
  }
  for (const e of entries) {
    const p = path.join(dir, e);
    let s;
    try {
      s = statSync(p);
    } catch {
      continue;
    }
    if (s.isDirectory()) files(p, out);
    else if (s.isFile() && s.size < 64 * 1024 * 1024) out.push(p);
  }
  return out;
}

/** Files holding the marker as UTF-8 or UTF-16 (Chromium stores some text as UTF-16). */
function holding(marker: string, paths: string[]): string[] {
  const needles = [Buffer.from(marker, "utf8"), Buffer.from(marker, "utf16le")];
  return paths.filter((p) => {
    try {
      const buf = readFileSync(p);
      return needles.some((n) => buf.includes(n));
    } catch {
      return false;
    }
  });
}

describe("no trace on disk", () => {
  it("Chromium's profile, cache and temp files never hold the document, during or after a render", async () => {
    const tmp = tmpdir();
    const before = new Set(existsSync(tmp) ? readdirSync(tmp) : []);
    const marker = `CANARY-${Math.random().toString(36).slice(2)}-DOCUMENT-TEXT`;
    const out = await renderer.pdf({ html: `<h1>${marker}</h1><p>${marker}</p>`, allowNetwork: false });
    expect(out.body.subarray(0, 5).toString()).toBe("%PDF-");

    // While the browser is still up: everything it created in the temp folder.
    const created = readdirSync(tmp).filter((e) => !before.has(e) || /playwright|chrom/i.test(e));
    const during = created.flatMap((e) => files(path.join(tmp, e)));
    expect(holding(marker, during)).toEqual([]);

    // And after it closes, in whatever is left.
    await renderer.close();
    const left = readdirSync(tmp).filter((e) => !before.has(e) || /playwright|chrom/i.test(e));
    expect(holding(marker, left.flatMap((e) => files(path.join(tmp, e))))).toEqual([]);
  }, 120_000);
});