using FluentAssertions;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using System;
using System.IO;
using System.Security.Cryptography;
using System.Security.Encryption;
using System.Text;
using System.Threading.Tasks;

namespace SystemExtensions.NetStandard.Security.Tests;

[TestClass]
public class AesEncrypterTests
{
    private ISymmetricEncrypter symmetricEncrypter;
    private string keyString;
    private byte[] keyBytes;
    private byte[] ivBytes;
    private string ivString;
    private string toEncryptString;
    private byte[] toEncryptBytes;

    [TestInitialize]
    public void TestInitialize()
    {
        this.symmetricEncrypter = new AesEncrypter();
        this.keyBytes = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2 };
        this.keyString = Convert.ToBase64String(this.keyBytes);
        this.ivBytes = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6 };
        this.ivString = Convert.ToBase64String(this.ivBytes);
        this.toEncryptBytes = Encoding.UTF8.GetBytes("toEncrypt");
        this.toEncryptString = Convert.ToBase64String(this.toEncryptBytes);
    }

    [TestMethod]
    public async Task EncryptDecryptStringWithStringKeyStringIv()
    {
        var encrypted = await this.symmetricEncrypter.Encrypt(this.keyString, this.ivString, this.toEncryptString).ConfigureAwait(false);
        var decrypted = await this.symmetricEncrypter.Decrypt(this.keyString, this.ivString, encrypted).ConfigureAwait(false);

        this.toEncryptString.Should().Be(decrypted);
    }

    [TestMethod]
    public async Task EncryptDecryptStringWithByteKeyByteIv()
    {
        var encrypted = await this.symmetricEncrypter.Encrypt(this.keyBytes, this.ivBytes, this.toEncryptString).ConfigureAwait(false);
        var decrypted = await this.symmetricEncrypter.Decrypt(this.keyBytes, this.ivBytes, encrypted).ConfigureAwait(false);

        this.toEncryptString.Should().Be(decrypted);
    }

    [TestMethod]
    public async Task EncryptDecryptByteWithStringKeyStringIv()
    {
        var encrypted = await this.symmetricEncrypter.Encrypt(this.keyString, this.ivString, this.toEncryptBytes).ConfigureAwait(false);
        var decrypted = await this.symmetricEncrypter.Decrypt(this.keyString, this.ivString, encrypted).ConfigureAwait(false);

        this.toEncryptBytes.Should().BeEquivalentTo(decrypted);
    }

    [TestMethod]
    public async Task EncryptDecryptByteWithByteKeyByteIv()
    {
        var encrypted = await this.symmetricEncrypter.Encrypt(this.keyBytes, this.ivBytes, this.toEncryptBytes).ConfigureAwait(false);
        var decrypted = await this.symmetricEncrypter.Decrypt(this.keyBytes, this.ivBytes, encrypted).ConfigureAwait(false);

        this.toEncryptBytes.Should().BeEquivalentTo(decrypted);
    }

    [TestMethod]
    public async Task EncryptDecryptStreamWithStringKeyStringIv()
    {
        var encrypted = await this.symmetricEncrypter.Encrypt(this.keyString, this.ivString, new MemoryStream(this.toEncryptBytes)).ConfigureAwait(false);
        encrypted.Position = 0;
        var decrypted = await this.symmetricEncrypter.Decrypt(this.keyString, this.ivString, encrypted).ConfigureAwait(false);

        this.toEncryptBytes.Should().BeEquivalentTo(((MemoryStream)decrypted).ToArray());
    }

    [TestMethod]
    public async Task EncryptDecryptStreamWithByteKeyByteIv()
    {
        var encrypted = await this.symmetricEncrypter.Encrypt(this.keyBytes, this.ivBytes, new MemoryStream(this.toEncryptBytes)).ConfigureAwait(false);
        encrypted.Position = 0;
        var decrypted = await this.symmetricEncrypter.Decrypt(this.keyBytes, this.ivBytes, encrypted).ConfigureAwait(false);

        this.toEncryptBytes.Should().BeEquivalentTo(((MemoryStream)decrypted).ToArray());
    }

    [TestMethod]
    public void GetEncryptionStreamReturnsCryptoStream()
    {
        var encryptionStream = this.symmetricEncrypter.GetEncryptionStream(this.keyBytes, this.ivBytes, new MemoryStream());
        encryptionStream.Should().BeAssignableTo<CryptoStream>();
    }

    [TestMethod]
    public void GetDecryptionStreamReturnsCryptoStream()
    {
        var encryptionStream = this.symmetricEncrypter.GetDecryptionStream(this.keyBytes, this.ivBytes, new MemoryStream());
        encryptionStream.Should().BeAssignableTo<CryptoStream>();
    }
}