#region Using Statements
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using ANX.Framework.NonXNA;
using SharpDX.Direct3D10;
using ANX.Framework.Graphics;
using System.Runtime.InteropServices;

#endregion // Using Statements

#region License

//
// This file is part of the ANX.Framework created by the "ANX.Framework developer group".
//
// This file is released under the Ms-PL license.
//
//
//
// Microsoft Public License (Ms-PL)
//
// This license governs use of the accompanying software. If you use the software, you accept this license. 
// If you do not accept the license, do not use the software.
//
// 1.Definitions
//   The terms "reproduce," "reproduction," "derivative works," and "distribution" have the same meaning 
//   here as under U.S. copyright law.
//   A "contribution" is the original software, or any additions or changes to the software.
//   A "contributor" is any person that distributes its contribution under this license.
//   "Licensed patents" are a contributor's patent claims that read directly on its contribution.
//
// 2.Grant of Rights
//   (A) Copyright Grant- Subject to the terms of this license, including the license conditions and limitations 
//       in section 3, each contributor grants you a non-exclusive, worldwide, royalty-free copyright license to 
//       reproduce its contribution, prepare derivative works of its contribution, and distribute its contribution
//       or any derivative works that you create.
//   (B) Patent Grant- Subject to the terms of this license, including the license conditions and limitations in 
//       section 3, each contributor grants you a non-exclusive, worldwide, royalty-free license under its licensed
//       patents to make, have made, use, sell, offer for sale, import, and/or otherwise dispose of its contribution 
//       in the software or derivative works of the contribution in the software.
//
// 3.Conditions and Limitations
//   (A) No Trademark License- This license does not grant you rights to use any contributors' name, logo, or trademarks.
//   (B) If you bring a patent claim against any contributor over patents that you claim are infringed by the software, your 
//       patent license from such contributor to the software ends automatically.
//   (C) If you distribute any portion of the software, you must retain all copyright, patent, trademark, and attribution 
//       notices that are present in the software.
//   (D) If you distribute any portion of the software in source code form, you may do so only under this license by including
//       a complete copy of this license with your distribution. If you distribute any portion of the software in compiled or 
//       object code form, you may only do so under a license that complies with this license.
//   (E) The software is licensed "as-is." You bear the risk of using it. The contributors give no express warranties, guarantees,
//       or conditions. You may have additional consumer rights under your local laws which this license cannot change. To the
//       extent permitted under your local laws, the contributors exclude the implied warranties of merchantability, fitness for a 
//       particular purpose and non-infringement.

#endregion // License

namespace ANX.Framework.Windows.DX10
{
    public class IndexBuffer_DX10 : INativeBuffer, IDisposable
    {
        private SharpDX.Direct3D10.Buffer buffer;
        private IndexElementSize size;

        public IndexBuffer_DX10(GraphicsDevice graphics, IndexElementSize size, int indexCount, BufferUsage usage)
        {
            this.size = size;

            //TODO: translate and use usage

            GraphicsDeviceWindowsDX10 gd10 = graphics.NativeDevice as GraphicsDeviceWindowsDX10;
            SharpDX.Direct3D10.Device device = gd10 != null ? gd10.NativeDevice as SharpDX.Direct3D10.Device : null;

            if (device != null)
            {
                BufferDescription description = new BufferDescription()
                {
                    Usage = ResourceUsage.Dynamic,
                    SizeInBytes = (size == IndexElementSize.SixteenBits ? 2 : 4) * indexCount,
                    BindFlags = BindFlags.IndexBuffer,
                    CpuAccessFlags = CpuAccessFlags.Write,
                    OptionFlags = ResourceOptionFlags.None
                };

                this.buffer = new SharpDX.Direct3D10.Buffer(device, description);
                this.buffer.Unmap();
            }
        }

        public void SetData<T>(GraphicsDevice graphicsDevice, T[] data) where T : struct
        {
            SetData<T>(graphicsDevice, data, 0, data.Length);
        }

        public void SetData<T>(GraphicsDevice graphicsDevice, int offsetInBytes, T[] data, int startIndex, int elementCount) where T : struct
        {
            if (startIndex > 0 || elementCount < data.Length)
            {
                throw new NotImplementedException("currently starIndex and elementCount of SetData are not implemented");
            }

            //TODO: check offsetInBytes parameter for bounds etc.

            GCHandle pinnedArray = GCHandle.Alloc(data, GCHandleType.Pinned); 
            IntPtr dataPointer = pinnedArray.AddrOfPinnedObject();

            int dataLength = Marshal.SizeOf(typeof(T)) * data.Length;

            unsafe
            {
                using (var vData = new SharpDX.DataStream(dataPointer, dataLength, true, false))
                {
                    if (offsetInBytes > 0)
                    {
                        vData.Seek(offsetInBytes / (size == IndexElementSize.SixteenBits ? 2 : 4), System.IO.SeekOrigin.Begin);
                    }

                    using (var d = buffer.Map(MapMode.WriteDiscard))
                    {
                        vData.CopyTo(d);
                        buffer.Unmap();
                    }
                }
            }

            pinnedArray.Free(); 
        }

        public void SetData<T>(GraphicsDevice graphicsDevice, T[] data, int startIndex, int elementCount) where T : struct
        {
            SetData<T>(graphicsDevice, 0, data, startIndex, elementCount);
        }

        public SharpDX.Direct3D10.Buffer NativeBuffer
        {
            get
            {
                return this.buffer;
            }
        }

        public void Dispose()
        {
            if (this.buffer != null)
            {
                buffer.Dispose();
                buffer = null;
            }
        }
    }
}