import { statSync } from "node:fs";
import { render } from "@testing-library/react";
import { OG_IMAGE_MAX_BYTES, OgCard, readProjectOgImage } from "./og-card";
import { PROJECT_VIDEO_IDS } from "./project-showcase";

jest.mock("node:fs", () => {
  const actual = jest.requireActual<typeof import("node:fs")>("node:fs");
  return { ...actual, statSync: jest.fn(actual.statSync) };
});

const mockedStatSync = jest.mocked(statSync);
const actualStatSync =
  jest.requireActual<typeof import("node:fs")>("node:fs").statSync;

afterEach(() => {
  mockedStatSync.mockImplementation(actualStatSync);
});

/** Largura e altura de um JPEG, lidas do primeiro marcador de quadro (SOF). */
function jpegSize(image: Buffer) {
  let offset = 2;
  while (offset < image.length) {
    const marker = image[offset + 1];
    const length = image.readUInt16BE(offset + 2);
    if (
      marker >= 0xc0 &&
      marker <= 0xcf &&
      marker !== 0xc4 &&
      marker !== 0xc8
    ) {
      return {
        height: image.readUInt16BE(offset + 5),
        width: image.readUInt16BE(offset + 7),
      };
    }
    offset += 2 + length;
  }
  throw new Error("JPEG sem marcador de quadro");
}

describe("readProjectOgImage", () => {
  it("returns the recorded cover of a showcase project as it is, in JPEG", () => {
    const image = readProjectOgImage("nutriscan");
    expect(image?.subarray(0, 2).toString("hex")).toBe("ffd8");
    expect(image?.length).toBeGreaterThan(5_000);
  });

  it("serves every recorded cover below 150 KB and in the 1200x630 card size", () => {
    expect(OG_IMAGE_MAX_BYTES).toBe(150_000);
    for (const id of PROJECT_VIDEO_IDS) {
      const image = readProjectOgImage(id);
      expect(image).toBeDefined();
      expect(image?.length ?? Infinity).toBeLessThan(150_000);
      expect(jpegSize(image as Buffer)).toEqual({ width: 1200, height: 630 });
    }
  });

  it("returns undefined for a cover that weighs the limit or more, so the plain card is used", () => {
    mockedStatSync.mockReturnValue({
      size: OG_IMAGE_MAX_BYTES,
    } as ReturnType<typeof statSync>);
    expect(readProjectOgImage("nutriscan")).toBeUndefined();

    mockedStatSync.mockReturnValue({
      size: OG_IMAGE_MAX_BYTES - 1,
    } as ReturnType<typeof statSync>);
    expect(readProjectOgImage("nutriscan")).toBeDefined();
  });

  it("returns undefined for projects without a recorded cover", () => {
    expect(readProjectOgImage("twins-lab")).toBeUndefined();
    expect(readProjectOgImage("../../etc/passwd")).toBeUndefined();
  });

  it("returns undefined when the file is missing on disk", () => {
    mockedStatSync.mockImplementation(() => {
      throw new Error("ENOENT");
    });
    expect(readProjectOgImage("nutriscan")).toBeUndefined();
  });
});

describe("OgCard", () => {
  const props = { eyebrow: "Case", title: "Título", description: "Resumo." };

  it("keeps the plain dark card when there is no background", () => {
    const { container } = render(<OgCard {...props} />);
    // só a marca
    expect(container.querySelectorAll("img")).toHaveLength(1);
  });

  it("puts the project cover behind the text with a darkening gradient", () => {
    const { container } = render(
      <OgCard {...props} backgroundImage="data:image/jpeg;base64,AAAA" />,
    );
    const images = [...container.querySelectorAll("img")];
    expect(images).toHaveLength(2);
    expect(images[0]).toHaveAttribute("src", "data:image/jpeg;base64,AAAA");
    expect(images[0]).toHaveAttribute("alt", "");
    expect(container.innerHTML).toContain("linear-gradient");
  });
});