// <copyright file="EncryptionBenchmarks.cs" company="MUnique">
// Licensed under the MIT License. See LICENSE file in the project root for full license information.
// </copyright>

namespace MUnique.OpenMU.Network.Benchmarks;

using System.Buffers;
using System.IO.Pipelines;
using MUnique.OpenMU.Network.SimpleModulus;
using MUnique.OpenMU.Network.Xor;

/// <summary>
/// Benchmarks for the simple modulus encryption.
/// </summary>
[SimpleJob(RuntimeMoniker.NetCoreApp31)]
[MemoryDiagnoser]
[InvocationCount(100)]
public class EncryptionBenchmarks
{
    /// <summary>
    /// The packet count for each benchmark run.
    /// </summary>
    private const int PacketCount = 100000;

    /// <summary>
    /// That's a 185 bytes unencrypted C3 packet. Encrypted it takes 255 bytes.
    /// </summary>
    private readonly byte[] _c3Packet = Convert.FromBase64String("w7kxFgK8hYpGGLgdXe7ZpTZViB+r3sRI3YSqZs7/Mh5Vmh2mXqs+3dqkvURmXrL57ASs+FkJz/236Tl9ER67R+WZyMLRMkeLF6tEBiB/4X7SsXrKUznES8of73RxwMy76HZezJbvJ7m9IOGuxcjcNwe6q1+k8fOs1Hz3sULSGlbfiB6qIBXo4onADTNYFoYCQrdtthVsF/aDsvcZ93V36gaKzzyqMhby0sjV4+TAU7719W6LZWNAcnA=");

    private readonly byte[] _c1Packet = Convert.FromBase64String("wf8AudHEjjSP53H6Rkp3oXj7B9z+rVDR2f0Is4bvsIsUL3RM/aTDB2FX9YG3Hkboy1Z1JThot558MeDTvNuunzfl5RbWK6TTOP97prjPGbq3IOcweopTq3fVz8vD8EuFqVVJ0jgvEZ+xoe047RHmrRgmG5zzfSWtkTmeAVzZD0i09f1jhUeBiA5HfticGr5m7iGzndSvkSwvm0D/kRBD15GlhPgTgyfQpJONrP5NEHd7NxI6JnJzBWPQM+kHgvb+BKdH95bFUmv54vlBIeUt4ovIg1r9CLEfMX+UQk89yCKcj6dXBRjgteSmQUN5MuN9o1FePv6cAPv2KMUXMBAc");

    /// <summary>
    /// Benchmarks the performance of the <see cref="SimpleModulusEncryptionAsync"/>.
    /// </summary>
    /// <returns>The value task.</returns>
    [Benchmark]
    public async ValueTask SimpleModulusEncryptionAsync()
    {
        var pipe = new Pipe();
        var pipelinedEncryptor = new PipelinedSimpleModulusEncryptor(pipe.Writer);
        var readBuffer = new byte[256];
        for (int i = 0; i < PacketCount; i++)
        {
            await pipelinedEncryptor.Writer.WriteAsync(this._c3Packet).ConfigureAwait(false);
            await pipelinedEncryptor.Writer.FlushAsync().ConfigureAwait(false);
            var readResult = await pipe.Reader.ReadAsync().ConfigureAwait(false);
            readResult.Buffer.CopyTo(readBuffer);
            //// In the server, I would process the readBuffer here
            pipe.Reader.AdvanceTo(readResult.Buffer.Start, readResult.Buffer.End);
        }

        await pipelinedEncryptor.Writer.CompleteAsync().ConfigureAwait(false);
    }

    /// <summary>
    /// Benchmarks the performance of the <see cref="MUnique.OpenMU.Network.Xor.PipelinedXor32Encryptor"/>.
    /// </summary>
    /// <returns>The value task.</returns>
    [Benchmark]
    public async ValueTask Xor32EncryptionAsync()
    {
        var pipe = new Pipe();
        var pipelinedEncryptor = new PipelinedXor32Encryptor(pipe.Writer);
        var readBuffer = new byte[256];
        for (int i = 0; i < PacketCount; i++)
        {
            await pipelinedEncryptor.Writer.WriteAsync(this._c1Packet).ConfigureAwait(false);
            await pipelinedEncryptor.Writer.FlushAsync().ConfigureAwait(false);
            var readResult = await pipe.Reader.ReadAsync().ConfigureAwait(false);
            readResult.Buffer.CopyTo(readBuffer);
            //// In the client/server, I would process the readBuffer here
            pipe.Reader.AdvanceTo(readResult.Buffer.Start, readResult.Buffer.End);
        }

        await pipelinedEncryptor.Writer.CompleteAsync().ConfigureAwait(false);
    }
}