import { mkdtemp, readdir } from "node:fs/promises";
import { tmpdir } from "node:os";
import path from "node:path";
import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";

const getUploadRootFromEnvMock = vi.fn();
let uploadRoot: string | null = null;

vi.mock("../../lib/server/uploads/uploadRoot", async () => {
  const actual = await vi.importActual<
    typeof import("../../lib/server/uploads/uploadRoot")
  >("../../lib/server/uploads/uploadRoot");
  return {
    ...actual,
    getUploadRootFromEnv: () => getUploadRootFromEnvMock(),
  };
});

import { saveCreateFlowUpload } from "../../lib/server/uploads/saveCreateFlowUpload";

const PNG_1X1 = Buffer.from(
  "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z8BQDwAEhQGAhKmMIQAAAABJRU5ErkJggg==",
  "base64",
);

describe("saveCreateFlowUpload", () => {
  beforeEach(async () => {
    uploadRoot = await mkdtemp(path.join(tmpdir(), "cr-upload-save-"));
    getUploadRootFromEnvMock.mockReset();
    getUploadRootFromEnvMock.mockImplementation(() => uploadRoot);
  });

  afterEach(() => {
    uploadRoot = null;
  });

  it("writes a sniffed PNG even when the client declared the wrong MIME", async () => {
    const saved = await saveCreateFlowUpload({
      purpose: "communityAvatar",
      buffer: PNG_1X1,
    });
    expect("error" in saved).toBe(false);
    if ("error" in saved) return;
    expect(saved.mimeType).toBe("image/png");
    const files = await readdir(uploadRoot!);
    expect(files).toEqual([`${saved.id}.png`]);
  });

  it("rejects spoofed bytes without writing", async () => {
    const saved = await saveCreateFlowUpload({
      purpose: "communityAvatar",
      buffer: Buffer.from("not an image"),
    });
    expect(saved).toEqual({ error: "validation", reason: "invalidType" });
    expect(await readdir(uploadRoot!)).toEqual([]);
  });
});