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);
    }
}