using Ryujinx.Graphics.GAL;
using SharpMetal.Metal;
using System.Collections.Generic;
using System.Runtime.Versioning;

namespace Ryujinx.Graphics.Metal
{
    public struct DirtyFlags
    {
        public bool Pipeline = false;
        public bool DepthStencil = false;

        public DirtyFlags() { }

        public void MarkAll()
        {
            Pipeline = true;
            DepthStencil = true;
        }

        public void Clear()
        {
            Pipeline = false;
            DepthStencil = false;
        }
    }

    [SupportedOSPlatform("macos")]
    struct EncoderState
    {
        public MTLFunction? VertexFunction = null;
        public MTLFunction? FragmentFunction = null;

        public MTLTexture[] FragmentTextures = new MTLTexture[Constants.MaxTextures];
        public MTLSamplerState[] FragmentSamplers = new MTLSamplerState[Constants.MaxSamplers];

        public MTLTexture[] VertexTextures = new MTLTexture[Constants.MaxTextures];
        public MTLSamplerState[] VertexSamplers = new MTLSamplerState[Constants.MaxSamplers];

        public List<BufferInfo> UniformBuffers = [];
        public List<BufferInfo> StorageBuffers = [];

        public MTLBuffer IndexBuffer = default;
        public MTLIndexType IndexType = MTLIndexType.UInt16;
        public ulong IndexBufferOffset = 0;

        public MTLDepthStencilState? DepthStencilState = null;

        public MTLDepthClipMode DepthClipMode = MTLDepthClipMode.Clip;
        public MTLCompareFunction DepthCompareFunction = MTLCompareFunction.Always;
        public bool DepthWriteEnabled = false;

        public MTLStencilDescriptor BackFaceStencil = new();
        public MTLStencilDescriptor FrontFaceStencil = new();
        public bool StencilTestEnabled = false;

        public PrimitiveTopology Topology = PrimitiveTopology.Triangles;
        public MTLCullMode CullMode = MTLCullMode.None;
        public MTLWinding Winding = MTLWinding.CounterClockwise;

        public MTLViewport[] Viewports = [];
        public MTLScissorRect[] Scissors = [];

        // Changes to attachments take recreation!
        public Texture DepthStencil = default;
        public Texture[] RenderTargets = new Texture[Constants.MaxColorAttachments];
        public BlendDescriptor?[] BlendDescriptors = new BlendDescriptor?[Constants.MaxColorAttachments];
        public ColorF BlendColor = new();

        public VertexBufferDescriptor[] VertexBuffers = [];
        public VertexAttribDescriptor[] VertexAttribs = [];

        // Dirty flags
        public DirtyFlags Dirty = new();

        // Only to be used for present
        public bool ClearLoadAction = false;

        public EncoderState() { }

        public EncoderState Clone()
        {
            // Certain state (like viewport and scissor) doesn't need to be cloned, as it is always reacreated when assigned to
            EncoderState clone = this;
            clone.FragmentTextures = (MTLTexture[])FragmentTextures.Clone();
            clone.FragmentSamplers = (MTLSamplerState[])FragmentSamplers.Clone();
            clone.VertexTextures = (MTLTexture[])VertexTextures.Clone();
            clone.VertexSamplers = (MTLSamplerState[])VertexSamplers.Clone();
            clone.BlendDescriptors = (BlendDescriptor?[])BlendDescriptors.Clone();
            clone.VertexBuffers = (VertexBufferDescriptor[])VertexBuffers.Clone();
            clone.VertexAttribs = (VertexAttribDescriptor[])VertexAttribs.Clone();

            return clone;
        }
    }
}