import { afterEach, describe, expect, it, vi } from "vitest";

// PCH-01-014: bound attacker-controlled page count and per-page render
// dimensions. Runs in the default node environment (no `document`), so
// renderPageToCanvas throws before any canvas is allocated — exactly the
// behaviour that lets us assert the clamps fire (or don't) by inspecting which
// per-page error surfaces.

function mockPdf(numPages: number, viewport: { width: number; height: number }) {
  const getPage = vi.fn(async () => ({ getViewport: () => viewport }));
  vi.doMock("pdfjs-dist", () => ({
    GlobalWorkerOptions: { workerSrc: "stub" },
    getDocument: () => ({ promise: Promise.resolve({ numPages, getPage }) }),
  }));
  return getPage;
}

function fakeFile(size = 1000): File {
  return { size, arrayBuffer: async () => new ArrayBuffer(8) } as unknown as File;
}

describe("PCH-01-014 — Codex PDF page/dimension clamps", () => {
  afterEach(() => {
    vi.resetModules();
    vi.doUnmock("pdfjs-dist");
  });

  it("importCodexPDF truncates page count at MAX_PDF_PAGES", async () => {
    const getPage = mockPdf(1000, { width: 600, height: 800 });
    const { importCodexPDF } = await import("./pdf-import");
    const result = await importCodexPDF(fakeFile());
    // 3 probe pages (detectRenderScale) + at most 250 main-loop pages.
    expect(getPage.mock.calls.length).toBeLessThanOrEqual(253);
    expect(result.errors.some((e) => e.includes("only the first 250"))).toBe(true);
  });

  it("renderPageToCanvas rejects an oversized viewport before allocating", async () => {
    mockPdf(1, { width: 14400 * 6, height: 14400 * 6 });
    const { importCodexPDF } = await import("./pdf-import");
    const result = await importCodexPDF(fakeFile());
    // The dimension guard throws before document.createElement, so the page
    // error is the render-limit message, not a "document is not defined".
    expect(result.errors.some((e) => e.includes("render limit"))).toBe(true);
  });

  it("does not fire the dimension clamp on a normal-sized page", async () => {
    mockPdf(3, { width: 600, height: 800 });
    const { importCodexPDF } = await import("./pdf-import");
    const result = await importCodexPDF(fakeFile());
    // No render-limit rejection for a legitimate A4-ish page, and no
    // page-count truncation message for a small document.
    expect(result.errors.some((e) => e.includes("render limit"))).toBe(false);
    expect(result.errors.some((e) => e.includes("only the first"))).toBe(false);
  });
});