'use strict';
const { test } = require('node:test');
const assert = require('node:assert');
const crypto = require('node:crypto');
const Sha256 = require('./sha256');

const ref = (buf) => crypto.createHash('sha256').update(buf).digest('hex');

test('known vectors', () => {
  assert.strictEqual(Sha256.hex(new Uint8Array(0)), 'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855');
  assert.strictEqual(Sha256.hex(new TextEncoder().encode('abc')), 'ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad');
  assert.strictEqual(
    Sha256.hex(new TextEncoder().encode('abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq')),
    '248d6a61d20638b8e5c026930c3e6039a33ce45964ff2167f6ecedd419db06c1');
});

test('every length around block boundaries matches node:crypto', () => {
  for (let n = 0; n <= 200; n++) {
    const buf = crypto.randomBytes(n);
    assert.strictEqual(Sha256.hex(new Uint8Array(buf)), ref(buf), 'length ' + n);
  }
});

test('random chunk boundaries give the same digest as one shot', () => {
  const buf = crypto.randomBytes(3 * 1024 * 1024 + 17);
  for (let round = 0; round < 5; round++) {
    const h = Sha256.create();
    let pos = 0;
    while (pos < buf.length) {
      const n = Math.min(buf.length - pos, 1 + Math.floor(Math.random() * 200000));
      h.update(new Uint8Array(buf.buffer, buf.byteOffset + pos, n));
      pos += n;
    }
    assert.strictEqual(h.hex(), ref(buf));
    assert.strictEqual(h.bytes, buf.length);
  }
});

test('update after digest throws; isHex', () => {
  const h = Sha256.create();
  h.hex();
  assert.throws(() => h.update(new Uint8Array(1)));
  assert.ok(Sha256.isHex(ref(Buffer.from('x'))));
  assert.ok(!Sha256.isHex('ABC'));
});