using System;
using System.IO;

using ACE.Common.Cryptography;

namespace ACE.Server.Network
{
    public class ClientPacketFragment : PacketFragment
    {
        public bool Unpack(BinaryReader payload)
        {
            Header.Unpack(payload);

            if (Header.Size - PacketFragmentHeader.HeaderSize < 0)
                return false;

            if (Header.Size > 464)
                return false;

            Data = payload.ReadBytes(Header.Size - PacketFragmentHeader.HeaderSize);

            return true;
        }

        public uint CalculateHash32()
        {
            Span<byte> buffer = stackalloc byte[PacketFragmentHeader.HeaderSize];

            Header.Pack(buffer);

            uint fragmentChecksum = Hash32.Calculate(buffer, buffer.Length) + Hash32.Calculate(Data, Data.Length);

            return fragmentChecksum;
        }
    }
}