#pragma once

#pragma push_macro("byte")
#pragma push_macro("GetNextSibling")
#pragma push_macro("GetFirstChild")
#undef byte
#undef GetNextSibling
#undef GetFirstChild

#include <RmlUi/Core/RenderInterface.h>
#include <d3d11.h>
#include <d3dcompiler.h>
#include <vector>

// NOTE: pop_macro at end of file

struct RmlD3D11Vertex
{
	float position[2];
	float texcoord[2];
	unsigned char color[4];
};

class RenderInterface_D3D11 : public Rml::RenderInterface
{
public:
	RenderInterface_D3D11(ID3D11Device* device, ID3D11DeviceContext* context);
	virtual ~RenderInterface_D3D11();

	bool IsInitialised() const { return m_initialised; }

	void BeginFrame();
	void EndFrame();

	void SetViewport(int width, int height);

	// Rml::RenderInterface
	Rml::CompiledGeometryHandle CompileGeometry(Rml::Span<const Rml::Vertex> vertices, Rml::Span<const int> indices) override;
	void RenderGeometry(Rml::CompiledGeometryHandle geometry, Rml::Vector2f translation, Rml::TextureHandle texture) override;
	void ReleaseGeometry(Rml::CompiledGeometryHandle geometry) override;

	Rml::TextureHandle LoadTexture(Rml::Vector2i& texture_dimensions, const Rml::String& source) override;
	Rml::TextureHandle GenerateTexture(Rml::Span<const Rml::byte> source_data, Rml::Vector2i source_dimensions) override;
	void ReleaseTexture(Rml::TextureHandle texture) override;

	void EnableScissorRegion(bool enable) override;
	void SetScissorRegion(Rml::Rectanglei region) override;

	void SetTransform(const Rml::Matrix4f* transform) override;

private:
	struct CompiledGeometry
	{
		ID3D11Buffer* vertex_buffer;
		ID3D11Buffer* index_buffer;
		int num_indices;
		int num_vertices;
		int vertex_stride;
		int index_stride;
		DXGI_FORMAT index_format;
	};

	struct TextureData
	{
		ID3D11ShaderResourceView* srv;
		int width;
		int height;
	};

	bool CompileShaders();
	bool CreateStateObjects();

	// Draws geometry with the current shader/projection
	void DrawCompiledGeometry(CompiledGeometry* geom, const Rml::Vector2f& translation, ID3D11ShaderResourceView* texture_srv);

	ID3D11Device* m_device;
	ID3D11DeviceContext* m_context;
	bool m_initialised;

	// Shaders
	ID3D11VertexShader* m_vertex_shader;
	ID3D11PixelShader* m_pixel_shader_textured;
	ID3D11PixelShader* m_pixel_shader_color;
	ID3D11InputLayout* m_input_layout;

	// State objects
	ID3D11BlendState* m_blend_state;
	ID3D11DepthStencilState* m_depth_state;
	ID3D11RasterizerState* m_raster_state;
	ID3D11SamplerState* m_sampler_state;

	// Constant buffer for projection
	ID3D11Buffer* m_projection_cb;
	Rml::Matrix4f m_projection;
	Rml::Matrix4f m_transform;
	bool m_transform_active;

	// Scissor state
	bool m_scissor_enabled;
	D3D11_RECT m_scissor_rect;

	// White fallback texture for untextured geometry
	ID3D11ShaderResourceView* m_white_texture;

	// Viewport dimensions
	int m_width;
	int m_height;

	// Geometry handle counter
	Rml::CompiledGeometryHandle m_next_geometry_handle;
	std::vector<CompiledGeometry*> m_geometry_lookup;

	// Texture handle counter
	Rml::TextureHandle m_next_texture_handle;
	std::vector<TextureData*> m_texture_lookup;
};

#pragma pop_macro("GetFirstChild")
#pragma pop_macro("GetNextSibling")
#pragma pop_macro("byte")