#region Using Statements
using System;
using System.Linq;
using System.Collections.Generic;
using ANX.Framework;
using ANX.Framework.Graphics;
using ANX.Framework.NonXNA;
using SharpDX.D3DCompiler;
using SharpDX.DXGI;
using SharpDX.Direct3D10;

#endregion

// This file is part of the ANX.Framework created by the
// "ANX.Framework developer group" and released under the Ms-PL license.
// For details see: http://anxframework.codeplex.com/license

using Dx10 = SharpDX.Direct3D10;

namespace ANX.RenderSystem.Windows.DX10
{
	public partial class GraphicsDeviceDX : INativeGraphicsDevice
	{
#if DEBUG
        static int graphicsDeviceCount = 0;
        static int swapChainCount = 0;
#endif
        //Restricted to 8 from DirectX side.
        const int MAX_RENDER_TARGETS = 8;

        #region Private
        private Dx10.Device nativeDevice;
        private Dx10.RenderTargetView[] renderTargetView = new RenderTargetView[MAX_RENDER_TARGETS];
        private Dx10.DepthStencilView[] depthStencilView = new DepthStencilView[MAX_RENDER_TARGETS];
        private RenderTarget2D_DX10 backBuffer;
        internal EffectPass_DX10 currentPass;
		#endregion

		#region CreateDevice
		protected void CreateDevice(PresentationParameters presentationParameters)
		{
			var desc = new SwapChainDescription()
			{
				BufferCount = 1,
				ModeDescription = new ModeDescription(
                    presentationParameters.BackBufferWidth,
                    presentationParameters.BackBufferHeight,
                    new Rational(60, 1),
                    DxFormatConverter.Translate(presentationParameters.BackBufferFormat)
                ),
				IsWindowed = true,
				OutputHandle = presentationParameters.DeviceWindowHandle,
				SampleDescription = new SampleDescription(1, 0),
				SwapEffect = SwapEffect.Discard,
				Usage = Usage.RenderTargetOutput | Usage.ShaderInput,
			};

			// http://msdn.microsoft.com/en-us/library/windows/desktop/bb205068(v=vs.85).aspx
#if DEBUG
			var flags = Dx10.DeviceCreationFlags.Debug;
#else
            var flags = Dx10.DeviceCreationFlags.None;
#endif
            var driverType = Dx10.DriverType.Hardware;
            if (GraphicsAdapter.UseReferenceDevice)
                driverType = DriverType.Reference;
            else if (GraphicsAdapter.UseNullDevice)
                driverType = DriverType.Null;

            Dx10.Device.CreateWithSwapChain(driverType, flags, desc, out nativeDevice, out swapChain);
#if DEBUG
            nativeDevice.DebugName = "GraphicsDevice_" + graphicsDeviceCount++;
            swapChain.DebugName = "SwapChain_" + swapChainCount++;
#endif

		}
		#endregion

		#region CreateRenderView
		protected void CreateRenderView(PresentationParameters presentationParameters)
		{
            backBuffer = new RenderTarget2D_DX10(this, Dx10.Texture2D.FromSwapChain<Dx10.Texture2D>(swapChain, 0), presentationParameters.DepthStencilFormat);
            this.SetRenderTargets();
		}
		#endregion

		#region Clear
        public void Clear(ClearOptions options, Vector4 color, float depth, int stencil)
        {
            if ((options & ClearOptions.Target) == ClearOptions.Target)
            {
                // Clear a RenderTarget (or BackBuffer)
                var clearColor = new SharpDX.Color4(color.X, color.Y, color.Z, color.W);

                for (int i = 0; i < MAX_RENDER_TARGETS; i++)
                {
                    if (this.renderTargetView[i] == null)
                        break;

                    nativeDevice.ClearRenderTargetView(this.renderTargetView[i], clearColor);
                }
            }

            Dx10.DepthStencilClearFlags clearFlags;
            if ((options | ClearOptions.Stencil | ClearOptions.DepthBuffer) == options)
            {
                clearFlags = Dx10.DepthStencilClearFlags.Depth | Dx10.DepthStencilClearFlags.Stencil;
            }
            else if ((options | ClearOptions.Stencil) == options)
            {
                clearFlags = Dx10.DepthStencilClearFlags.Stencil;
            }
            else
            {
                clearFlags = Dx10.DepthStencilClearFlags.Depth;
            }

            for (int i = 0; i < MAX_RENDER_TARGETS; i++)
            {
                if (this.depthStencilView[i] == null)
                    break;

                nativeDevice.ClearDepthStencilView(this.depthStencilView[i], clearFlags, depth, (byte)stencil);
            }
        }
		#endregion

        #region Present
        public void Present()
        {
			swapChain.Present(VSync ? 1 : 0, PresentFlags.None);
        }

        public void Present(Rectangle? sourceRectangle, Rectangle? destinationRectangle, WindowHandle overrideWindowHandle)
        {
            throw new NotImplementedException();
        }
        #endregion

        private void SetupDraw(PrimitiveType primitiveType)
        {
            var inputLayout = this.inputLayoutManager.GetInputLayout(NativeDevice, currentPass.Signature, this.currentVertexBuffer);

            nativeDevice.InputAssembler.PrimitiveTopology = DxFormatConverter.Translate(primitiveType);
            if (currentInputLayout != inputLayout)
            {
                nativeDevice.InputAssembler.InputLayout = inputLayout;
                currentInputLayout = inputLayout;
            }
        }

		#region SetVertexBuffers
        public void SetVertexBuffers(ANX.Framework.Graphics.VertexBufferBinding[] vertexBuffers)
        {
            if (vertexBuffers == null)
                throw new ArgumentNullException("vertexBuffers");

            if (this.currentVertexBuffer.SequenceEqual(vertexBuffers))
                return;

            this.currentVertexBufferCount = vertexBuffers.Length;

            if (this.currentVertexBuffer == null || this.currentVertexBuffer.Length < currentVertexBufferCount)
            {
                this.currentVertexBuffer = new ANX.Framework.Graphics.VertexBufferBinding[currentVertexBufferCount];
            }

            for (int i = 0; i < this.currentVertexBufferCount; i++)
            {
                this.currentVertexBuffer[i] = vertexBuffers[i];
            }

            Dx10.VertexBufferBinding[] nativeVertexBufferBindings = new Dx10.VertexBufferBinding[vertexBuffers.Length];
            for (int i = 0; i < vertexBuffers.Length; i++)
            {
                ANX.Framework.Graphics.VertexBufferBinding anxVertexBufferBinding = vertexBuffers[i];
                var nativeVertexBuffer = anxVertexBufferBinding.VertexBuffer.NativeVertexBuffer as DxVertexBuffer;

                if (nativeVertexBuffer != null)
                {
                    int vertexStride = anxVertexBufferBinding.VertexBuffer.VertexDeclaration.VertexStride;
                    nativeVertexBufferBindings[i] = new Dx10.VertexBufferBinding(nativeVertexBuffer.NativeBuffer, vertexStride, anxVertexBufferBinding.VertexOffset * vertexStride);
                }
                else
                {
                    throw new Exception("couldn't fetch native DirectX10 VertexBuffer");
                }
            }

			nativeDevice.InputAssembler.SetVertexBuffers(0, nativeVertexBufferBindings);
		}
		#endregion

		#region SetViewport
		protected void SetViewport(int x, int y, int width, int height, float minDepth, float maxDepth)
		{
            nativeDevice.Rasterizer.SetViewports(new SharpDX.Viewport(x, y, width, height, minDepth, maxDepth));
		}

        protected void SetViewport(params SharpDX.Viewport[] viewports)
        {
            nativeDevice.Rasterizer.SetViewports(viewports);
        }
        #endregion

		#region SetRenderTargets
		public void SetRenderTargets(params RenderTargetBinding[] renderTargets)
        {
            if (renderTargets == null || renderTargets.Length == 0)
            {
                this.renderTargetView[0] = this.backBuffer.RenderTargetView;
                this.depthStencilView[0] = this.backBuffer.DepthStencilView;

                for (int i = 1; i < MAX_RENDER_TARGETS; i++)
                {
                    this.renderTargetView[i] = null;
                    this.depthStencilView[i] = null;
                }

                //To correctly unset renderTargets, the amount of given rendertargetViews must be max(#previousRenderTargets, #newRenderTargets),
                //otherwise the old ones at the slots stay bound. For us it means, we try to unbind every possible previous slot.
                nativeDevice.OutputMerger.SetRenderTargets(MAX_RENDER_TARGETS, this.renderTargetView, this.backBuffer.DepthStencilView);
                nativeDevice.Rasterizer.SetViewports(new SharpDX.Viewport(0, 0, this.backBuffer.Width, this.backBuffer.Height));
            }
            else
            {
                int renderTargetCount = renderTargets.Length;
                if (renderTargetCount > MAX_RENDER_TARGETS)
                    throw new NotSupportedException(string.Format("{0} render targets are not supported. The maximum is {1}.", renderTargetCount, MAX_RENDER_TARGETS));

                SharpDX.Viewport[] rtViewports = new SharpDX.Viewport[renderTargetCount];

                var firstRenderTarget = renderTargets[0].RenderTarget as RenderTarget2D;
                for (int i = 1; i < renderTargetCount; i++)
                {
                    var renderTarget = renderTargets[i].RenderTarget as RenderTarget2D;
                    if (renderTarget.Width != firstRenderTarget.Width || renderTarget.Height != firstRenderTarget.Height || renderTarget.MultiSampleCount != firstRenderTarget.MultiSampleCount)
                        throw new ArgumentException("The render targets don't match");
                }

                for (int i = 0; i < renderTargetCount; i++)
                {
                    RenderTarget2D renderTarget = renderTargets[i].RenderTarget as RenderTarget2D;
                    RenderTarget2D_DX10 nativeRenderTarget = renderTarget.NativeRenderTarget as RenderTarget2D_DX10;

                    renderTargetView[i] = nativeRenderTarget.RenderTargetView;
                    depthStencilView[i] = nativeRenderTarget.DepthStencilView;
                    rtViewports[i] = new SharpDX.Viewport(0, 0, renderTarget.Width, renderTarget.Height);
                }

                for (int i = renderTargetCount; i < MAX_RENDER_TARGETS; i++)
                {
                    this.renderTargetView[i] = null;
                    this.depthStencilView[i] = null;
                }

                nativeDevice.OutputMerger.SetRenderTargets(MAX_RENDER_TARGETS, renderTargetView, this.depthStencilView[0]);
                nativeDevice.Rasterizer.SetViewports(rtViewports);
            }
        }
		#endregion

		protected void DisposeBackBuffer()
		{
            if (backBuffer != null)
            {
                for (int i = 0; i < MAX_RENDER_TARGETS; i++)
                {
                    this.renderTargetView[i] = null;
                    this.depthStencilView[i] = null;
                }

                nativeDevice.OutputMerger.SetRenderTargets(MAX_RENDER_TARGETS, this.renderTargetView, null);

                backBuffer.Dispose();
                backBuffer = null;
            }
		}

        internal Dx10.Device NativeDevice
        {
            get
            {
                return this.nativeDevice;
            }
        }

        public Rectangle ScissorRectangle
        {
            get { throw new NotImplementedException(); }
            set { throw new NotImplementedException(); }
        }
    }
}