/*
* Assorted commonly used Vulkan helper functions
*
* Copyright (C) 2016 by Sascha Willems - www.saschawillems.de
*
* This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
*/

#pragma once

#include "vulkan/vulkan.h"

#include <math.h>
#include <stdlib.h>
#include <string>
#include <cstring>
#include <fstream>
#include <assert.h>
#include <stdio.h>
#include <vector>
#include <iostream>
#ifdef _WIN32
#include <windows.h>
#include <fcntl.h>
#include <io.h>
#else
#endif

// Custom define for better code readability
#define VK_FLAGS_NONE 0

namespace vkTools
{
	// Check if extension is globally available
	VkBool32 checkGlobalExtensionPresent(const char* extensionName);
	// Check if extension is present on the given device
	VkBool32 checkDeviceExtensionPresent(VkPhysicalDevice physicalDevice, const char* extensionName);
	// Return string representation of a vulkan error string
	std::string errorString(VkResult errorCode);
	
	// Selected a suitable supported depth format starting with 32 bit down to 16 bit
	// Returns false if none of the depth formats in the list is supported by the device
	VkBool32 getSupportedDepthFormat(VkPhysicalDevice physicalDevice, VkFormat *depthFormat);

	// Put an image memory barrier for setting an image layout into the given command buffer
	void setImageLayout(
		VkCommandBuffer cmdbuffer, 
		VkImage image, 
		VkImageAspectFlags aspectMask, 
		VkImageLayout oldImageLayout, 
		VkImageLayout newImageLayout);

	// Display error message and exit on fatal error
	void exitFatal(std::string message, std::string caption);
	// Load a text file (e.g. GLGL shader) into a std::string
	std::string readTextFile(const char *fileName);
	// Load a binary file into a buffer (e.g. SPIR-V)
	char *readBinaryFile(const char *filename, size_t *psize);
	// Load a SPIR-V shader
	VkShaderModule loadShader(const char *fileName, VkDevice device, VkShaderStageFlagBits stage);
	// Load a GLSL shader
	// Note : Only for testing purposes, support for directly feeding GLSL shaders into Vulkan
	// may be dropped at some point	
	VkShaderModule loadShaderGLSL(const char *fileName, VkDevice device, VkShaderStageFlagBits stage);

	// Returns a pre-present image memory barrier
	// Transforms the image's layout from color attachment to present khr
	VkImageMemoryBarrier prePresentBarrier(VkImage presentImage);

	// Returns a post-present image memory barrier
	// Transforms the image's layout back from present khr to color attachment
	VkImageMemoryBarrier postPresentBarrier(VkImage presentImage);

	// Contains all vulkan objects
	// required for a uniform data object
	struct UniformData 
	{
		VkBuffer buffer;
		VkDeviceMemory memory;
		VkDescriptorBufferInfo descriptor;
		uint32_t allocSize;
	};

	// Destroy (and free) Vulkan resources used by a uniform data structure
	void destroyUniformData(VkDevice device, vkTools::UniformData *uniformData);

	// Contains often used vulkan object initializers
	// Save lot of VK_STRUCTURE_TYPE assignments
	// Some initializers are parameterized for convenience
	namespace initializers
	{
		VkMemoryAllocateInfo memoryAllocateInfo();

		VkCommandBufferAllocateInfo commandBufferAllocateInfo(
			VkCommandPool commandPool,
			VkCommandBufferLevel level,
			uint32_t bufferCount);

		VkCommandPoolCreateInfo commandPoolCreateInfo();
		VkCommandBufferBeginInfo commandBufferBeginInfo();
		VkCommandBufferInheritanceInfo commandBufferInheritanceInfo();

		VkRenderPassBeginInfo renderPassBeginInfo();
		VkRenderPassCreateInfo renderPassCreateInfo();

		VkImageMemoryBarrier imageMemoryBarrier();
		VkBufferMemoryBarrier bufferMemoryBarrier();
		VkMemoryBarrier memoryBarrier();

		VkImageCreateInfo imageCreateInfo();
		VkSamplerCreateInfo samplerCreateInfo();
		VkImageViewCreateInfo imageViewCreateInfo();

		VkFramebufferCreateInfo framebufferCreateInfo();

		VkSemaphoreCreateInfo semaphoreCreateInfo();
		VkFenceCreateInfo fenceCreateInfo(VkFenceCreateFlags flags);

		VkSubmitInfo submitInfo();

		VkViewport viewport(
			float width, 
			float height, 
			float minDepth, 
			float maxDepth);

		VkRect2D rect2D(
			int32_t width,
			int32_t height,
			int32_t offsetX,
			int32_t offsetY);

		VkBufferCreateInfo bufferCreateInfo(
			VkBufferUsageFlags usage, 
			VkDeviceSize size);

		VkDescriptorPoolCreateInfo descriptorPoolCreateInfo(
			uint32_t poolSizeCount,
			VkDescriptorPoolSize* pPoolSizes,
			uint32_t maxSets);

		VkDescriptorPoolSize descriptorPoolSize(
			VkDescriptorType type,
			uint32_t descriptorCount);

		VkDescriptorSetLayoutBinding descriptorSetLayoutBinding(
			VkDescriptorType type, 
			VkShaderStageFlags stageFlags, 
			uint32_t binding);

		VkDescriptorSetLayoutCreateInfo descriptorSetLayoutCreateInfo(
			const VkDescriptorSetLayoutBinding* pBindings,
			uint32_t bindingCount);

		VkPipelineLayoutCreateInfo pipelineLayoutCreateInfo(
			const VkDescriptorSetLayout* pSetLayouts,
			uint32_t setLayoutCount	);

		VkDescriptorSetAllocateInfo descriptorSetAllocateInfo(
			VkDescriptorPool descriptorPool,
			const VkDescriptorSetLayout* pSetLayouts,
			uint32_t descriptorSetCount);

		VkDescriptorImageInfo descriptorImageInfo(
			VkSampler sampler,
			VkImageView imageView,
			VkImageLayout imageLayout);

		VkWriteDescriptorSet writeDescriptorSet(
			VkDescriptorSet dstSet, 
			VkDescriptorType type, 
			uint32_t binding, 
			VkDescriptorBufferInfo* bufferInfo);

		VkWriteDescriptorSet writeDescriptorSet(
			VkDescriptorSet dstSet, 
			VkDescriptorType type, 
			uint32_t binding, 
			VkDescriptorImageInfo* imageInfo);

		VkVertexInputBindingDescription vertexInputBindingDescription(
			uint32_t binding, 
			uint32_t stride, 
			VkVertexInputRate inputRate);

		VkVertexInputAttributeDescription vertexInputAttributeDescription(
			uint32_t binding,
			uint32_t location,
			VkFormat format,
			uint32_t offset);

		VkPipelineVertexInputStateCreateInfo pipelineVertexInputStateCreateInfo();

		VkPipelineInputAssemblyStateCreateInfo pipelineInputAssemblyStateCreateInfo(
			VkPrimitiveTopology topology,
			VkPipelineInputAssemblyStateCreateFlags flags,
			VkBool32 primitiveRestartEnable);

		VkPipelineRasterizationStateCreateInfo pipelineRasterizationStateCreateInfo(
			VkPolygonMode polygonMode,
			VkCullModeFlags cullMode,
			VkFrontFace frontFace,
			VkPipelineRasterizationStateCreateFlags flags);

		VkPipelineColorBlendAttachmentState pipelineColorBlendAttachmentState(
			VkColorComponentFlags colorWriteMask,
			VkBool32 blendEnable);

		VkPipelineColorBlendStateCreateInfo pipelineColorBlendStateCreateInfo(
			uint32_t attachmentCount,
			const VkPipelineColorBlendAttachmentState* pAttachments);

		VkPipelineDepthStencilStateCreateInfo pipelineDepthStencilStateCreateInfo(
			VkBool32 depthTestEnable,
			VkBool32 depthWriteEnable,
			VkCompareOp depthCompareOp);

		VkPipelineViewportStateCreateInfo pipelineViewportStateCreateInfo(
			uint32_t viewportCount,
			uint32_t scissorCount,
			VkPipelineViewportStateCreateFlags flags);

		VkPipelineMultisampleStateCreateInfo pipelineMultisampleStateCreateInfo(
			VkSampleCountFlagBits rasterizationSamples,
			VkPipelineMultisampleStateCreateFlags flags);

		VkPipelineDynamicStateCreateInfo pipelineDynamicStateCreateInfo(
			const VkDynamicState *pDynamicStates,
			uint32_t dynamicStateCount,
			VkPipelineDynamicStateCreateFlags flags);

		VkPipelineTessellationStateCreateInfo pipelineTessellationStateCreateInfo(
			uint32_t patchControlPoints);

		VkGraphicsPipelineCreateInfo pipelineCreateInfo(
			VkPipelineLayout layout,
			VkRenderPass renderPass,
			VkPipelineCreateFlags flags);

		VkComputePipelineCreateInfo computePipelineCreateInfo(
			VkPipelineLayout layout,
			VkPipelineCreateFlags flags);

		VkPushConstantRange pushConstantRange(
			VkShaderStageFlags stageFlags,
			uint32_t size,
			uint32_t offset);
	}

}