import { createHash } from "node:crypto";
import { describe, expect, it } from "vitest";
import { Sha256 } from "./media-sha256";

const node = (data: Uint8Array) => createHash("sha256").update(data).digest("hex");
const text = (value: string) => new TextEncoder().encode(value);

describe("Sha256", () => {
  it("matches known vectors", () => {
    expect(new Sha256().hex()).toBe(
      "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
    );
    expect(new Sha256().update(text("abc")).hex()).toBe(
      "ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad",
    );
  });

  it("matches node:crypto across block boundaries", () => {
    for (const size of [1, 55, 56, 63, 64, 65, 119, 120, 128, 1000, 4097]) {
      const data = new Uint8Array(size);
      for (let index = 0; index < size; index++) data[index] = (index * 13 + size) & 0xff;
      expect(new Sha256().update(data).hex()).toBe(node(data));
    }
  });

  it("gives the same digest however the input is split", () => {
    const data = new Uint8Array(5000);
    for (let index = 0; index < data.length; index++) data[index] = (index * 7) & 0xff;
    for (const step of [1, 3, 63, 64, 100, 4096]) {
      const hash = new Sha256();
      for (let offset = 0; offset < data.length; offset += step) {
        hash.update(data.subarray(offset, offset + step));
      }
      expect(hash.hex()).toBe(node(data));
    }
  });

  it("refuses updates after finishing", () => {
    const hash = new Sha256();
    hash.hex();
    expect(() => hash.update(text("x"))).toThrow();
    expect(() => hash.hex()).toThrow();
  });
});