using System;
using BenchmarkDotNet.Running;
using BenchmarkDotNet.Attributes;
using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;

namespace ConsoleApp2
{
    public class Program
    {
        private static MemoryPool _pool;
        private static MemoryPoolIterator _iter;
        private static ulong _expectedResult;
        private static long _oldExpectedResult;

        static Program()
        {
            var blockBytes = 0;
            _pool = new MemoryPool();

            // Arrange
            _expectedResult = 0x0102030405060708UL;
            _oldExpectedResult = (long)_expectedResult;
            //var nonZeroData = 0xFF00FFFF0000FFFFUL;
            var nextBlockBytes = 8 - blockBytes;

            var block = _pool.Lease();
            block.Start += 8;
            block.End = block.Start + blockBytes;

            var nextBlock = _pool.Lease();
            nextBlock.Start += 8;
            nextBlock.End = nextBlock.Start + nextBlockBytes;

            block.Next = nextBlock;

            var bytes = BitConverter.GetBytes(_expectedResult);
            Buffer.BlockCopy(bytes, 0, block.Array, block.Start, blockBytes);
            Buffer.BlockCopy(bytes, blockBytes, nextBlock.Array, nextBlock.Start, nextBlockBytes);

            // Fill in surrounding bytes with non-zero data
            //var nonZeroBytes = BitConverter.GetBytes(nonZeroData);
            //Buffer.BlockCopy(nonZeroBytes, 0, block.Array, block.Start - 8, 8);
            //Buffer.BlockCopy(nonZeroBytes, 0, block.Array, block.End, 8);
            //Buffer.BlockCopy(nonZeroBytes, 0, nextBlock.Array, nextBlock.Start - 8, 8);
            //Buffer.BlockCopy(nonZeroBytes, 0, nextBlock.Array, nextBlock.End, 8);

             _iter = block.GetIterator();
        }

        public static void Main(string[] args)
        {
            new Program().TestPeekLong();
            new Program().TestOldPeekLong();
            var summary = BenchmarkRunner.Run<Program>();
            Console.WriteLine(summary);
        }

        [Benchmark]
        public void TestPeekLong()
        {
            ulong? result = _iter.PeekLong();
            if (result != _expectedResult)
            {
                throw new Exception();
            }
        }

        [Benchmark]
        public void TestOldPeekLong()
        {
            long result = _iter.OldPeekLong();
            if (result != _oldExpectedResult)
            {
                throw new Exception();
            }
        }
    }
}