#pragma once
#include "vulkan/basalt_render_pass.h"

namespace basalt
{
	typedef VkVertexInputBindingDescription (*PFN_GetVertexInputBindingDescription)(void);
	typedef VkResult(*PFN_GetVertexAttributeDescriptions)(VkVertexInputAttributeDescription* out_attachments, u32* num_attachments);


	class Pipeline
	{
	public:
		Pipeline(const Pipeline& src) = delete;
		Pipeline& operator =(const Pipeline& src) = delete;
		Pipeline(Pipeline&& other) noexcept;
		Pipeline& operator =(Pipeline&& other) noexcept;

		Pipeline(basalt::Device& device, VkPipeline pipeline, VkPipelineLayout layout);
		~Pipeline();

		void swap(Pipeline& other) noexcept;

		VkPipeline vk = VK_NULL_HANDLE;
		VkPipelineLayout layout = VK_NULL_HANDLE;
		basalt::Device* device = nullptr;
		bool should_free = true;
	};

	class PipelineBuilder
	{
	public:
		PipelineBuilder(basalt::Device& device, VkExtent2D extent, VkPipeline previous_pipeline=VK_NULL_HANDLE);
		~PipelineBuilder();

		PipelineBuilder& add_shader(const char* fpath, VkShaderStageFlagBits stage, const char* entry="main");
		PipelineBuilder& add_dynamic_state(const VkDynamicState state);
		PipelineBuilder& add_dynamic_states(const VkDynamicState* states, const u32 num_states);
		PipelineBuilder& add_dynamic_states(const basalt::darray<VkDynamicState>& states);
		PipelineBuilder& set_render_pass(VkRenderPass render_pass);
		PipelineBuilder& add_colour_attachment(VkPipelineColorBlendAttachmentState attachment);
		PipelineBuilder& add_vertex_binding(VkVertexInputBindingDescription binding, VkVertexInputAttributeDescription* attributes, u32 num_attributes);

		template <typename T>
		PipelineBuilder& add_vertex_binding(void);

		Pipeline build();


		VkPipelineRasterizationStateCreateInfo raster_ci;
		VkPipelineColorBlendStateCreateInfo colour_blend_ci;
		VkPipelineLayoutCreateInfo layout_ci;
		VkPipelineVertexInputStateCreateInfo vertex_ci;
		VkPipelineMultisampleStateCreateInfo multisample_ci;
		VkPipelineViewportStateCreateInfo viewport_ci;
		VkPipelineInputAssemblyStateCreateInfo assembly_ci;
		VkPipelineDynamicStateCreateInfo dynamic_state_ci;
		basalt::darray<VkVertexInputAttributeDescription> vertex_input_attributes;
		basalt::darray<VkVertexInputBindingDescription> vertex_binding_description;
		basalt::darray<VkShaderModule> shader_modules;
		basalt::darray<VkPipelineShaderStageCreateInfo> shader_stages;
		basalt::darray<VkPipelineColorBlendAttachmentState> colour_attachments;
		basalt::darray<VkDynamicState> dynamic_states;
		VkViewport viewport;
		VkRect2D scissor;
		basalt::Device& device;
		VkRenderPass render_pass = VK_NULL_HANDLE;
		VkPipeline previous_pipeline = VK_NULL_HANDLE;
	protected:
		/// <summary>
		/// Will read all of the contents of a file into outptr
		/// Should outptr not be big enough or nullptr, it will be allocated
		/// If it is not big enough it will be reallocated
		/// </summary>
		/// <param name="fpath">Path to the file to read</param>
		/// <param name="outptr">A reference to a pointer that may be updated</param>
		/// <param name="size">Size of an existing allocation associated with outptr</param>
		/// <returns>Number of bytes read from the file</returns>
		static size_t read_file(const char* fpath, char*& outptr, size_t& outptr_size);
	};
	template<typename T>
	inline PipelineBuilder& PipelineBuilder::add_vertex_binding(void)
	{
		VkResult err = VK_SUCCESS;
		this->vertex_binding_description.push_back(T::get_binding_description());
		u32 sz = 0;
		VK_ASSERT(T::get_attribute_descriptions(nullptr, &sz), "Failed to get number of vertex attribute descriptions for object\n\tAt %s:%d\n\tError %s\n\tObject %s\n", typeid(T).name());
		this->vertex_input_attributes.expand(sz);
		VK_ASSERT(T::get_attribute_descriptions(this->vertex_input_attributes.end(), &sz), "Failed to get vertex attribute descriptions for object\n\tAt %s:%d\n\tError %s\n\tObject %s\n", typeid(T).name());
		this->vertex_input_attributes.resize(this->vertex_input_attributes.m_nelements + sz);
		return *this;
	}
}