using BenchmarkDotNet.Attributes;
using System.Text;

namespace Benchmarks.Console.Memory;

[MemoryDiagnoser]
public class Utf8Strings
{
    private const string Dummy32 = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";
    private const string Dummy64 = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";
    private const string Dummy128 = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";

    private readonly MemoryStream _stream = new(1_024);

    [Benchmark]
    public ReadOnlySpan<byte> GetUtf8Value_32_u16const()
    {
        return Encoding.UTF8.GetBytes(Dummy32);
    }

    [Benchmark]
    public ReadOnlySpan<byte> GetUtf8Value_32_u8const()
    {
        return "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"u8;
    }

    [Benchmark]
    public ReadOnlySpan<byte> GetUtf8Value_64_u16const()
    {
        return Encoding.UTF8.GetBytes(Dummy64);
    }

    [Benchmark]
    public ReadOnlySpan<byte> GetUtf8Value_64_u8const()
    {
        return "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"u8;
    }

    [Benchmark]
    public ReadOnlySpan<byte> GetUtf8Value_128_u16const()
    {
        return Encoding.UTF8.GetBytes(Dummy128);
    }

    [Benchmark]
    public ReadOnlySpan<byte> GetUtf8Value_128_u8const()
    {
        return "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"u8;
    }

    [Benchmark]
    [ArgumentsSource(nameof(GetAuthValues))]
    public void WriteAuthHeaderToStream_u16const(string value)
    {
        var authHeaderName = Encoding.UTF8.GetBytes("Authorization: ");
        var authHeaderValue = Encoding.UTF8.GetBytes(value);

        _stream.Seek(0, SeekOrigin.Begin); // Prevent OutOfMemoryException when running the benchmark (which obviously not reinstantiates the class for each run)
        _stream.Write(authHeaderName.AsSpan());
        _stream.Write(authHeaderValue.AsSpan());
    }

    [Benchmark]
    [ArgumentsSource(nameof(GetAuthValues))]
    public void WriteAuthHeaderToStream_u8const(string value)
    {
        var authHeaderValue = Encoding.UTF8.GetBytes(value);

        _stream.Seek(0, SeekOrigin.Begin); // Prevent OutOfMemoryException when running the benchmark (which obviously not reinstantiates the class for each run)
        _stream.Write("Authorization: "u8);
        _stream.Write(authHeaderValue.AsSpan());
    }

    public static IEnumerable<object[]> GetAuthValues()
    {
        yield return new object[] { Dummy32 };
        yield return new object[] { Dummy64 };
        yield return new object[] { Dummy128 };
    }
}