using System;
using System.Linq;
using System.Runtime.CompilerServices;

namespace FrostFS.SDK.Cryptography;

internal static class ArrayHelper
{
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static byte[] Concat(params byte[][] buffers)
    {
        var length = buffers.Sum(buffer => buffer.Length);

        var dst = new byte[length];
        var p = 0;
        foreach (var src in buffers)
        {
            Buffer.BlockCopy(src, 0, dst, p, src.Length);
            p += src.Length;
        }

        return dst;
    }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static void GetRevertedArray(ReadOnlySpan<byte> source, byte[] data)
    {
        if (source.Length != 0)
        {
            int i = 0;
            int j = source.Length - 1;
            while (i < source.Length)
            {
                data[i++] = source[j--];
            }
        }
    }
}