using System;
using System.Runtime.InteropServices;
using ANX.Framework.NonXNA;
using ANX.Framework.NonXNA.RenderSystem;
using ANX.Framework.NonXNA.Development;

// 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

namespace ANX.Framework.Graphics
{
    [PercentageComplete(75)]
    [Developer("Glatzemann")]
    [TestState(TestStateAttribute.TestState.Untested)]
    public class GraphicsDevice : IDisposable
    {
        #region Private Members
        private SamplerStateCollection samplerStateCollection;
        private Viewport viewport;
        private BlendState blendState;
        private RasterizerState rasterizerState;
        private DepthStencilState depthStencilState;
        private GraphicsAdapter currentAdapter;
        private PresentationParameters currentPresentationParameters;
        private bool isDisposed;
        private GraphicsProfile graphicsProfile;
        private VertexBufferBinding[] currentVertexBufferBindings;
        private RenderTargetBinding[] currentRenderTargetBindings;
        private TextureCollection vertexTextureCollection;
        private TextureCollection textureCollection;

        #endregion // Private Members

        #region Events
        public event EventHandler<EventArgs> Disposing;
        public event EventHandler<ResourceDestroyedEventArgs> ResourceDestroyed;
        public event EventHandler<ResourceCreatedEventArgs> ResourceCreated;
        public event EventHandler<EventArgs> DeviceLost;
        public event EventHandler<EventArgs> DeviceReset;
        public event EventHandler<EventArgs> DeviceResetting;

        #endregion // Events

        #region Constructor & Destructor
        public GraphicsDevice(GraphicsAdapter adapter, GraphicsProfile graphicsProfile,
            PresentationParameters presentationParameters)
        {
            this.currentAdapter = adapter;
            this.graphicsProfile = graphicsProfile;

            this.viewport = new Viewport(0, 0, presentationParameters.BackBufferWidth, presentationParameters.BackBufferHeight);

            Recreate(presentationParameters);

            // TODO: get maximum number of sampler states from capabilities
            this.samplerStateCollection = new SamplerStateCollection(this, 8);
            this.textureCollection = new TextureCollection(16);
            this.vertexTextureCollection = new TextureCollection(16);

            samplerStateCollection.InitializeDeviceState();
            this.BlendState = BlendState.Opaque;
            this.DepthStencilState = DepthStencilState.Default;
            this.RasterizerState = RasterizerState.CullCounterClockwise;
        }

        ~GraphicsDevice()
        {
            this.Dispose(false);
        }
        #endregion // Constructor & Destructor

        #region Clear
        public void Clear(Color color)
        {
            ClearOptions options = ClearOptions.Target;
            if (this.currentPresentationParameters.DepthStencilFormat != DepthFormat.None)
                options |= ClearOptions.DepthBuffer;
            if (this.currentPresentationParameters.DepthStencilFormat == DepthFormat.Depth24Stencil8)
                options |= ClearOptions.Stencil;

            Clear(options, color, 1, 0);
            // nativeDevice.Clear(ref color);
        }

        public void Clear(ClearOptions options, Color color, float depth, int stencil)
        {
            Clear(options, color.ToVector4(), depth, stencil);
        }

        public void Clear(ClearOptions options, Vector4 color, float depth, int stencil)
        {
            if ((options & ClearOptions.DepthBuffer) == ClearOptions.DepthBuffer &&
                this.currentPresentationParameters.DepthStencilFormat == DepthFormat.None)
            {
                throw new InvalidOperationException("The depth buffer can only be cleared if it exists. The current " +
                    "DepthStencilFormat is DepthFormat.None");
            }

            if ((options & ClearOptions.Stencil) == ClearOptions.Stencil &&
                this.currentPresentationParameters.DepthStencilFormat != DepthFormat.Depth24Stencil8)
            {
                throw new InvalidOperationException("The stencil buffer can only be cleared if it exists. The current " +
                    "DepthStencilFormat is not DepthFormat.Depth24Stencil8");
            }

            NativeDevice.Clear(options, color, depth, stencil);
        }

        #endregion // Clear

        #region Present
        public void Present()
        {
            NativeDevice.Present();
        }

        public void Present(Rectangle? sourceRectangle, Rectangle? destinationRectangle, WindowHandle overrideWindowHandle)
        {
            NativeDevice.Present(sourceRectangle, destinationRectangle, overrideWindowHandle);
        }

        #endregion // Present

        #region DrawPrimitives & DrawIndexedPrimitives
        public void DrawIndexedPrimitives(PrimitiveType primitiveType, int baseVertex, int minVertexIndex, int numVertices, int startIndex, int primitiveCount)
        {
            NativeDevice.DrawIndexedPrimitives(primitiveType, baseVertex, minVertexIndex, numVertices, startIndex, primitiveCount);
        }

        public void DrawPrimitives(PrimitiveType primitiveType, int startVertex, int primitiveCount)
        {
            NativeDevice.DrawPrimitives(primitiveType, startVertex, primitiveCount);
        }
        #endregion

        #region DrawInstancedPrimitives
        public void DrawInstancedPrimitives(PrimitiveType primitiveType, int baseVertex, int minVertexIndex, int numVertices,
            int startIndex, int primitiveCount, int instanceCount)
        {
            NativeDevice.DrawInstancedPrimitives(primitiveType, baseVertex, minVertexIndex, numVertices, startIndex,
                primitiveCount, instanceCount);
        }
        #endregion

        #region DrawUserIndexedPrimitives<T>
        public void DrawUserIndexedPrimitives<T>(PrimitiveType primitiveType, T[] vertexData, int vertexOffset, int numVertices,
            short[] indexData, int indexOffset, int primitiveCount) where T : struct, IVertexType
        {
            var vertexDeclaration = VertexTypeHelper.GetDeclaration<T>();
            NativeDevice.DrawUserIndexedPrimitives<T>(primitiveType, vertexData, vertexOffset, numVertices, indexData,
                indexOffset, primitiveCount, vertexDeclaration, IndexElementSize.SixteenBits);
        }

        public void DrawUserIndexedPrimitives<T>(PrimitiveType primitiveType, T[] vertexData, int vertexOffset, int numVertices,
            short[] indexData, int indexOffset, int primitiveCount, VertexDeclaration vertexDeclaration)
            where T : struct, IVertexType
        {
            NativeDevice.DrawUserIndexedPrimitives<T>(primitiveType, vertexData, vertexOffset, numVertices, indexData,
                indexOffset, primitiveCount, vertexDeclaration, IndexElementSize.SixteenBits);
        }

        public void DrawUserIndexedPrimitives<T>(PrimitiveType primitiveType, T[] vertexData, int vertexOffset, int numVertices,
            int[] indexData, int indexOffset, int primitiveCount) where T : struct, IVertexType
        {
            var vertexDeclaration = VertexTypeHelper.GetDeclaration<T>();
            NativeDevice.DrawUserIndexedPrimitives<T>(primitiveType, vertexData, vertexOffset, numVertices, indexData,
                indexOffset, primitiveCount, vertexDeclaration, IndexElementSize.ThirtyTwoBits);
        }

        public void DrawUserIndexedPrimitives<T>(PrimitiveType primitiveType, T[] vertexData, int vertexOffset, int numVertices,
            int[] indexData, int indexOffset, int primitiveCount, VertexDeclaration vertexDeclaration)
            where T : struct, IVertexType
        {
            NativeDevice.DrawUserIndexedPrimitives<T>(primitiveType, vertexData, vertexOffset, numVertices, indexData,
                indexOffset, primitiveCount, vertexDeclaration, IndexElementSize.ThirtyTwoBits);
        }
        #endregion

        #region DrawUserPrimitives<T>
        public void DrawUserPrimitives<T>(PrimitiveType primitiveType, T[] vertexData, int vertexOffset, int primitiveCount)
            where T : struct, IVertexType
        {
            var vertexDeclaration = VertexTypeHelper.GetDeclaration<T>();
            NativeDevice.DrawUserPrimitives<T>(primitiveType, vertexData, vertexOffset, primitiveCount, vertexDeclaration);
        }

        public void DrawUserPrimitives<T>(PrimitiveType primitiveType, T[] vertexData, int vertexOffset, int primitiveCount,
            VertexDeclaration vertexDeclaration) where T : struct, IVertexType
        {
            NativeDevice.DrawUserPrimitives<T>(primitiveType, vertexData, vertexOffset, primitiveCount, vertexDeclaration);
        }
        #endregion
        
#if XNAEXT
        #region SetConstantBuffer
        /// <summary>
        /// Binds a ConstantBuffer to the current GraphicsDevice
        /// </summary>
        /// <param name="slot">The index of the constant buffer used in the shader</param>
        /// <param name="constantBuffer">The managed constant buffer object to bind.</param>
        public void SetConstantBuffer(int slot, ConstantBuffer constantBuffer)
        {
            NativeDevice.SetConstantBuffer(slot, constantBuffer);
        }

        /// <summary>
        /// Binds ConstantBuffer objects to the current GraphicsDevice.
        /// </summary>
        /// <param name="constantBuffers">The array of managed constant buffer objects to bind.</param>
        /// <remarks>The constant buffer objects are bound in the order found in the passed array.</remarks>
        public void SetConstantBuffers(params ConstantBuffer[] constantBuffers)
        {
            for (int slot = 0; slot < constantBuffers.Length; slot++)
                NativeDevice.SetConstantBuffer(slot, constantBuffers[slot]);
        }

        #endregion
#endif

        #region SetVertexBuffer
        public void SetVertexBuffer(VertexBuffer vertexBuffer)
        {
            if (vertexBuffer != null)
            {
                VertexBufferBinding[] bindings = new VertexBufferBinding[] { new VertexBufferBinding(vertexBuffer) };
                this.currentVertexBufferBindings = bindings;
                NativeDevice.SetVertexBuffers(bindings);
            }
            else
            {
                SetVertexBuffers(null);
            }
        }

        public void SetVertexBuffer(VertexBuffer vertexBuffer, int vertexOffset)
        {
            if (vertexBuffer != null)
            {
                VertexBufferBinding[] bindings = new VertexBufferBinding[] { new VertexBufferBinding(vertexBuffer, vertexOffset) };
                this.currentVertexBufferBindings = bindings;
                NativeDevice.SetVertexBuffers(bindings);
            }
            else
            {
                SetVertexBuffers(null);
            }
        }

        public void SetVertexBuffers(params Graphics.VertexBufferBinding[] vertexBuffers)
        {
            this.currentVertexBufferBindings = vertexBuffers;
            NativeDevice.SetVertexBuffers(vertexBuffers);
        }

        #endregion // SetVertexBuffer

        #region SetRenderTarget
        public void SetRenderTarget(RenderTarget2D renderTarget)
        {
            if (renderTarget != null)
            {
                RenderTargetBinding[] renderTargetBindings = new RenderTargetBinding[] { new RenderTargetBinding(renderTarget) };
                this.currentRenderTargetBindings = renderTargetBindings;
                NativeDevice.SetRenderTargets(renderTargetBindings);
            }
            else
                NativeDevice.SetRenderTargets(null);
        }

        public void SetRenderTarget(RenderTargetCube renderTarget, CubeMapFace cubeMapFace)
        {
            RenderTargetBinding[] renderTargetBindings = new RenderTargetBinding[] { new RenderTargetBinding(renderTarget, cubeMapFace) };
            this.currentRenderTargetBindings = renderTargetBindings;
            NativeDevice.SetRenderTargets(renderTargetBindings);
        }

        public void SetRenderTargets(params RenderTargetBinding[] renderTargets)
        {
            this.currentRenderTargetBindings = renderTargets;
            NativeDevice.SetRenderTargets(renderTargets);
        }

        #endregion // SetRenderTarget

        #region GetBackBufferData<T>
        public void GetBackBufferData<T>(Nullable<Rectangle> rect, T[] data, int startIndex, int elementCount) where T : struct
        {
            NativeDevice.GetBackBufferData<T>(rect, data, startIndex, elementCount);
        }

        public void GetBackBufferData<T>(T[] data) where T : struct
        {
            NativeDevice.GetBackBufferData<T>(data);
        }

        public void GetBackBufferData<T>(T[] data, int startIndex, int elementCount) where T : struct
        {
            NativeDevice.GetBackBufferData<T>(data, startIndex, elementCount);
        }

        #endregion // GetBackBufferData<T>

        public VertexBufferBinding[] GetVertexBuffers()
        {
            return this.currentVertexBufferBindings;
        }

        public RenderTargetBinding[] GetRenderTargets()
        {
            return this.currentRenderTargetBindings;
        }

        #region Reset
        public void Reset()
        {
            this.Reset(this.currentPresentationParameters, this.currentAdapter);
        }

        public void Reset(PresentationParameters presentationParameters)
        {
            this.Reset(presentationParameters, this.currentAdapter);
        }

        public void Reset(PresentationParameters presentationParameters, GraphicsAdapter adapter)
        {
            if (presentationParameters == null)
            {
                throw new ArgumentNullException("presentationParameters");
            }

            if (adapter == null)
            {
                throw new ArgumentNullException("adapter");
            }

            if (this.currentAdapter != adapter)
            {
                throw new InvalidOperationException("adapter switch not yet implemented");
            }

            raise_DeviceResetting(this, EventArgs.Empty);

            // As it seems that no hardware Depth24 exists we handle Depth24
            // and Depth24Stencil8 the same way. Problem is that the Clear method
            // checks for Depth24Stencil8 when trying to clear the stencil buffer
            // and the format is set to Depth24. Internally Depth24 is already
            // handled as Depth24Stencil8 so it is interchangeable.
            if ((this.currentPresentationParameters.DepthStencilFormat == DepthFormat.Depth24 ||
                this.currentPresentationParameters.DepthStencilFormat == DepthFormat.Depth24Stencil8) &&
                (presentationParameters.DepthStencilFormat == DepthFormat.Depth24 ||
                presentationParameters.DepthStencilFormat == DepthFormat.Depth24Stencil8))
            {
                this.currentPresentationParameters.DepthStencilFormat = presentationParameters.DepthStencilFormat;
            }

            // reset presentation parameters
            NativeDevice.ResizeBuffers(presentationParameters);
            this.viewport = new Graphics.Viewport(0, 0, presentationParameters.BackBufferWidth, presentationParameters.BackBufferHeight);
            this.currentPresentationParameters = presentationParameters;

            samplerStateCollection.InitializeDeviceState();

            raise_DeviceReset(this, EventArgs.Empty);
        }

        #endregion // Reset

        #region Dispose (TODO)
        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        protected virtual void Dispose([MarshalAs(UnmanagedType.U1)] bool disposeManaged)
        {
            if (isDisposed == false)
            {
                isDisposed = true;
                if (NativeDevice != null)
                {
                    NativeDevice.Dispose();
                    NativeDevice = null;
                }

                raise_Disposing(this, EventArgs.Empty);
                //TODO: more to dispose?
            }
        }
        #endregion

        #region Public Properties
        public IndexBuffer Indices
        {
            get
            {
                return this.NativeDevice.IndexBuffer;
            }
            set
            {
                this.NativeDevice.IndexBuffer = value;
            }
        }

        public Viewport Viewport
        {
            get
            {
                return this.viewport;
            }
            set
            {
                this.viewport = value;
                NativeDevice.SetViewport(this.viewport);    //TODO: this is not optimal...
            }
        }

        public BlendState BlendState
        {
            get
            {
                return this.blendState;
            }
            set
            {
                if (this.blendState != value)
                {
                    if (this.blendState != null)
                    {
                        this.blendState.NativeBlendState.Release();
                    }

                    this.blendState = value;

                    this.blendState.NativeBlendState.Apply(this);
                }
            }
        }

        public DepthStencilState DepthStencilState
        {
            get
            {
                return this.depthStencilState;
            }
            set
            {
                if (this.depthStencilState != value)
                {
                    if (this.depthStencilState != null)
                    {
                        this.depthStencilState.NativeDepthStencilState.Release();
                    }

                    this.depthStencilState = value;

                    this.depthStencilState.NativeDepthStencilState.Apply(this);
                }
            }
        }

        public RasterizerState RasterizerState
        {
            get
            {
                return this.rasterizerState;
            }
            set
            {
                if (this.rasterizerState != value)
                {
                    if (this.rasterizerState != null)
                    {
                        this.rasterizerState.NativeRasterizerState.Release();
                    }

                    this.rasterizerState = value;

                    this.rasterizerState.NativeRasterizerState.Apply(this);
                }
            }
        }

        public SamplerStateCollection SamplerStates
        {
            get
            {
                return this.samplerStateCollection;
            }
        }

        public bool IsDisposed
        {
            get
            {
                return this.isDisposed;
            }
        }

        public DisplayMode DisplayMode
        {
            get
            {
                return this.currentAdapter.CurrentDisplayMode;
            }
        }

        public GraphicsProfile GraphicsProfile
        {
            get
            {
                return this.graphicsProfile;
            }
        }

        public GraphicsAdapter Adapter
        {
            get
            {
                return this.currentAdapter;
            }
        }

        public PresentationParameters PresentationParameters
        {
            get
            {
                return this.currentPresentationParameters;
            }
        }

        public int ReferenceStencil
        {
            get
            {
                return DepthStencilState.ReferenceStencil;
            }
            set
            {
                if (DepthStencilState.ReferenceStencil != value)
                {
                    DepthStencilState.ReferenceStencil = value;
                }
            }
        }

        public int MultiSampleMask
        {
            get
            {
                return BlendState.MultiSampleMask;
            }
            set
            {
                if (BlendState.MultiSampleMask != value)
                {
                    BlendState.MultiSampleMask = value;
                }
            }
        }

        public Color BlendFactor
        {
            get
            {
                return BlendState.BlendFactor;
            }
            set
            {
                if (BlendState.BlendFactor != value)
                {
                    BlendState.BlendFactor = value;
                }
            }
        }

        public TextureCollection VertexTextures
        {
            get
            {
                return this.vertexTextureCollection;
            }
        }

        public TextureCollection Textures
        {
            get
            {
                return this.textureCollection;
            }
        }

        #endregion // Public Properties

        public Rectangle ScissorRectangle
        {
            get { return NativeDevice.ScissorRectangle; }
            set { NativeDevice.ScissorRectangle = value; }
        }

        public GraphicsDeviceStatus GraphicsDeviceStatus
        {
            get
            {
                throw new NotImplementedException();
            }
        }

        public SamplerStateCollection VertexSamplerStates
        {
            get
            {
                throw new NotImplementedException();
            }
        }

        internal INativeGraphicsDevice NativeDevice
        {
            get;
            set;
        }

        internal void Recreate(PresentationParameters presentationParameters)
        {
            if (NativeDevice != null)
            {
                NativeDevice.Dispose();
                raise_ResourceDestroyed(this, new ResourceDestroyedEventArgs("NativeGraphicsDevice", NativeDevice));
                NativeDevice = null;
            }

            if (NativeDevice == null)
            {
                this.currentPresentationParameters = presentationParameters;
                var creator = AddInSystemFactory.Instance.GetDefaultCreator<IRenderSystemCreator>();
                NativeDevice = creator.CreateGraphicsDevice(presentationParameters);
                this.viewport = new Viewport(0, 0, presentationParameters.BackBufferWidth,
                    presentationParameters.BackBufferHeight);

                raise_ResourceCreated(this, new ResourceCreatedEventArgs(NativeDevice));
                GraphicsResourceTracker.Instance.UpdateGraphicsDeviceReference(this);

                if (this.currentVertexBufferBindings != null)
                    NativeDevice.SetVertexBuffers(this.currentVertexBufferBindings);

                if (this.blendState != null)
                    this.blendState.NativeBlendState.Apply(this);

                if (this.rasterizerState != null)
                    this.rasterizerState.NativeRasterizerState.Apply(this);

                if (this.depthStencilState != null)
                    this.depthStencilState.NativeDepthStencilState.Apply(this);

                if (this.samplerStateCollection != null)
                {
                    for (int i = 0; i < 8; i++)
                    {
                        if (this.samplerStateCollection[i] != null)
                            this.samplerStateCollection[i].NativeSamplerState.Apply(this, i);
                    }
                }
            }
        }

        protected void raise_Disposing(object sender, EventArgs args)
        {
            RaiseIfNotNull(Disposing, sender, args);
        }

        protected void raise_DeviceResetting(object sender, EventArgs args)
        {
            RaiseIfNotNull(DeviceResetting, sender, args);
        }

        protected void raise_DeviceReset(object sender, EventArgs args)
        {
            RaiseIfNotNull(DeviceReset, sender, args);
        }

        protected void raise_DeviceLost(object sender, EventArgs args)
        {
            RaiseIfNotNull(DeviceLost, sender, args);
        }

        protected void raise_ResourceCreated(object sender, ResourceCreatedEventArgs args)
        {
            RaiseIfNotNull(ResourceCreated, sender, args);
        }

        protected void raise_ResourceDestroyed(object sender, ResourceDestroyedEventArgs args)
        {
            RaiseIfNotNull(ResourceDestroyed, sender, args);
        }

        private void RaiseIfNotNull<T>(EventHandler<T> handler, object sender, T args) where T : EventArgs
        {
            if (handler != null)
                handler(sender, args);
        }
    }
}