using System;
using LibHac.Crypto;
using Xunit;

namespace LibHac.Tests.CryptoTests
{
    internal static class Common
    {
        internal delegate ICipher CipherCreator(byte[] key, byte[] iv);

        internal static void CipherTestCore(byte[] inputData, byte[] expected, ICipher cipher)
        {
            byte[] transformBuffer = new byte[inputData.Length];
            Buffer.BlockCopy(inputData, 0, transformBuffer, 0, inputData.Length);

            cipher.Transform(transformBuffer, transformBuffer);

            Assert.Equal(expected, transformBuffer);
        }

        internal static void EncryptCipherTest(EncryptionTestVector[] testVectors, CipherCreator cipherGenerator)
        {
            foreach (EncryptionTestVector tv in testVectors)
            {
                CipherTestCore(tv.PlainText, tv.CipherText, cipherGenerator(tv.Key, tv.Iv));
            }
        }

        internal static void DecryptCipherTest(EncryptionTestVector[] testVectors, CipherCreator cipherGenerator)
        {
            foreach (EncryptionTestVector tv in testVectors)
            {
                CipherTestCore(tv.CipherText, tv.PlainText, cipherGenerator(tv.Key, tv.Iv));
            }
        }

        internal static void HashTestCore(ReadOnlySpan<byte> message, byte[] expectedDigest, IHash hash)
        {
            byte[] digestBuffer = new byte[Sha256.DigestSize];

            hash.Initialize();
            hash.Update(message);
            hash.GetHash(digestBuffer);

            Assert.Equal(expectedDigest, digestBuffer);
        }
    }
}