//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
//     file="DataHead.cs"
//     Project: StgSharp
//     AuthorGroup: Nitload Space
//     Copyright (c) Nitload Space. All rights reserved.
//     
//     Permission is hereby granted, free of charge, to any person 
//     obtaining a copy of this software and associated documentation 
//     files (the “Software”), to deal in the Software without restriction, 
//     including without limitation the rights to use, copy, modify, merge,
//     publish, distribute, sublicense, and/or sell copies of the Software, 
//     and to permit persons to whom the Software is furnished to do so, 
//     subject to the following conditions:
//     
//     The above copyright notice and 
//     this permission notice shall be included in all copies 
//     or substantial portions of the Software.
//     
//     THE SOFTWARE IS PROVIDED “AS IS”, 
//     WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
//     INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
//     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
//     IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
//     DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
//     ARISING FROM, OUT OF OR IN CONNECTION WITH 
//     THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//     
//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
using StgSharp.HighPerformance;

using System;
using System.Numerics;
using System.Runtime.InteropServices;

namespace StgSharp.Internal
{
    [StructLayout( LayoutKind.Explicit, Size = 16 )]
    public struct SSDSegmentHead
    {

        [FieldOffset( 12 )] internal byte size;

        [FieldOffset( 0 )] internal M128 data;
        [FieldOffset( 13 )] public byte selfDefine_1;
        [FieldOffset( 14 )] public byte selfDefine_2;
        [FieldOffset( 15 )] public byte selfDefine_3;

        [FieldOffset( 0 )] public int globalID;
        [FieldOffset( 4 )] public int nextID;
        [FieldOffset( 8 )] public int previousHash;

        public int Size
        {
            get => ( ( int )size ) + 1;
            set
            {
                if( ( value > 256 ) || ( value < 0 ) ) {
                    throw new ArgumentOutOfRangeException();
                }
                size = ( byte )( value - 1 );
            }
        }

        public unsafe byte[] GetBytes()
        {
            byte[] ret = new byte[16];
            fixed( Vector4* vptr = &data.Vec ) {
                byte* bptr = ( byte* )vptr;
                for( int i = 0; i < 15; i++ ) {
                    ret[ i ] = *bptr;
                }
            }
            return ret;
        }

    }
}