/*
* Vulkan Example -  Mesh rendering and loading using ASSIMP
*
* Copyright (C) 2016 by Sascha Willems - www.saschawillems.de
*
* This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <vector>

#define GLM_FORCE_RADIANS
#define GLM_FORCE_DEPTH_ZERO_TO_ONE
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>

#include <vulkan/vulkan.h>
#include "vulkanexamplebase.h"

#define VERTEX_BUFFER_BIND_ID 0
#define ENABLE_VALIDATION false

// Vertex layout used in this example
struct Vertex {
	glm::vec3 pos;
	glm::vec3 normal;
	glm::vec2 uv;
	glm::vec3 color;
};

class VulkanExample : public VulkanExampleBase
{
public:
	bool wireframe = false;

	struct {
		vkTools::VulkanTexture colorMap;
	} textures;

	struct {
		VkPipelineVertexInputStateCreateInfo inputState;
		std::vector<VkVertexInputBindingDescription> bindingDescriptions;
		std::vector<VkVertexInputAttributeDescription> attributeDescriptions;
	} vertices;

	// Contains all buffers and information
	// necessary to represent a mesh for rendering purposes
	// This is for demonstration and learning purposes,
	// the other examples use a mesh loader class for easy access
	struct Mesh {
		struct {
			VkBuffer buf;
			VkDeviceMemory mem;
		} vertices;
		struct {
			int count;
			VkBuffer buf;
			VkDeviceMemory mem;
		} indices;
	} mesh;

	struct {
		vkTools::UniformData vsScene;
	} uniformData;

	struct {
		glm::mat4 projection;
		glm::mat4 model;
		glm::vec4 lightPos = glm::vec4(25.0f, 5.0f, 5.0f, 1.0f);
	} uboVS;

	struct {
		VkPipeline solid;
		VkPipeline wireframe;
	} pipelines;

	VkPipelineLayout pipelineLayout;
	VkDescriptorSet descriptorSet;
	VkDescriptorSetLayout descriptorSetLayout;

	VulkanExample() : VulkanExampleBase(ENABLE_VALIDATION)
	{
		zoom = -5.5f;
		zoomSpeed = 2.5f;
		rotationSpeed = 0.5f;
		rotation = { -0.5f, -112.75f, 0.0f };
		cameraPos = { 0.1f, 1.1f, 0.0f };
		enableTextOverlay = true;
		title = "Vulkan Example - Mesh rendering";
	}

	~VulkanExample()
	{
		// Clean up used Vulkan resources 
		// Note : Inherited destructor cleans up resources stored in base class
		vkDestroyPipeline(device, pipelines.solid, nullptr);

		vkDestroyPipelineLayout(device, pipelineLayout, nullptr);
		vkDestroyDescriptorSetLayout(device, descriptorSetLayout, nullptr);

		// Destroy and free mesh resources 
		vkDestroyBuffer(device, mesh.vertices.buf, nullptr);
		vkFreeMemory(device, mesh.vertices.mem, nullptr);
		vkDestroyBuffer(device, mesh.indices.buf, nullptr);
		vkFreeMemory(device, mesh.indices.mem, nullptr);

		textureLoader->destroyTexture(textures.colorMap);

		vkTools::destroyUniformData(device, &uniformData.vsScene);
	}

	void reBuildCommandBuffers()
	{
		if (!checkCommandBuffers())
		{
			destroyCommandBuffers();
			createCommandBuffers();
		}
		buildCommandBuffers();
	}

	void buildCommandBuffers()
	{
		VkCommandBufferBeginInfo cmdBufInfo = vkTools::initializers::commandBufferBeginInfo();

		VkClearValue clearValues[2];
		clearValues[0].color = defaultClearColor;
		clearValues[1].depthStencil = { 1.0f, 0 };

		VkRenderPassBeginInfo renderPassBeginInfo = vkTools::initializers::renderPassBeginInfo();
		renderPassBeginInfo.renderPass = renderPass;
		renderPassBeginInfo.renderArea.offset.x = 0;
		renderPassBeginInfo.renderArea.offset.y = 0;
		renderPassBeginInfo.renderArea.extent.width = width;
		renderPassBeginInfo.renderArea.extent.height = height;
		renderPassBeginInfo.clearValueCount = 2;
		renderPassBeginInfo.pClearValues = clearValues;

		for (int32_t i = 0; i < drawCmdBuffers.size(); ++i)
		{
			// Set target frame buffer
			renderPassBeginInfo.framebuffer = frameBuffers[i];

			VK_CHECK_RESULT(vkBeginCommandBuffer(drawCmdBuffers[i], &cmdBufInfo));

			vkCmdBeginRenderPass(drawCmdBuffers[i], &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);

			VkViewport viewport = vkTools::initializers::viewport((float)width, (float)height, 0.0f, 1.0f);
			vkCmdSetViewport(drawCmdBuffers[i], 0, 1, &viewport);

			VkRect2D scissor = vkTools::initializers::rect2D(width, height, 0, 0);
			vkCmdSetScissor(drawCmdBuffers[i], 0, 1, &scissor);

			vkCmdBindDescriptorSets(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout, 0, 1, &descriptorSet, 0, NULL);
			vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, wireframe ? pipelines.wireframe : pipelines.solid);

			VkDeviceSize offsets[1] = { 0 };
			// Bind mesh vertex buffer
			vkCmdBindVertexBuffers(drawCmdBuffers[i], VERTEX_BUFFER_BIND_ID, 1, &mesh.vertices.buf, offsets);
			// Bind mesh index buffer
			vkCmdBindIndexBuffer(drawCmdBuffers[i], mesh.indices.buf, 0, VK_INDEX_TYPE_UINT32);
			// Render mesh vertex buffer using it's indices
			vkCmdDrawIndexed(drawCmdBuffers[i], mesh.indices.count, 1, 0, 0, 0);

			vkCmdEndRenderPass(drawCmdBuffers[i]);

			VK_CHECK_RESULT(vkEndCommandBuffer(drawCmdBuffers[i]));
		}
	}

	// Load a mesh based on data read via assimp 
	// The other example will use the VulkanMesh loader which has some additional functionality for loading meshes
	void loadMesh()
	{
		VulkanMeshLoader *meshLoader = new VulkanMeshLoader(vulkanDevice);
#if defined(__ANDROID__)
		meshLoader->assetManager = androidApp->activity->assetManager;
#endif
		meshLoader->LoadMesh(getAssetPath() + "models/voyager/voyager.dae");

		// Generate vertex buffer
		float scale = 1.0f;
		std::vector<Vertex> vertexBuffer;
		// Iterate through all meshes in the file
		// and extract the vertex information used in this demo
		for (uint32_t m = 0; m < meshLoader->m_Entries.size(); m++)
		{
			for (uint32_t i = 0; i < meshLoader->m_Entries[m].Vertices.size(); i++)
			{
				Vertex vertex;

				vertex.pos = meshLoader->m_Entries[m].Vertices[i].m_pos * scale;
				vertex.normal = meshLoader->m_Entries[m].Vertices[i].m_normal;
				vertex.uv = meshLoader->m_Entries[m].Vertices[i].m_tex;
				vertex.color = meshLoader->m_Entries[m].Vertices[i].m_color;

				vertexBuffer.push_back(vertex);
			}
		}
		uint32_t vertexBufferSize = vertexBuffer.size() * sizeof(Vertex);

		// Generate index buffer from loaded mesh file
		std::vector<uint32_t> indexBuffer;
		for (uint32_t m = 0; m < meshLoader->m_Entries.size(); m++)
		{
			uint32_t indexBase = indexBuffer.size();
			for (uint32_t i = 0; i < meshLoader->m_Entries[m].Indices.size(); i++)
			{
				indexBuffer.push_back(meshLoader->m_Entries[m].Indices[i] + indexBase);
			}
		}
		uint32_t indexBufferSize = indexBuffer.size() * sizeof(uint32_t);
		mesh.indices.count = indexBuffer.size();

		// Static mesh should always be device local

		bool useStaging = true;

		if (useStaging)
		{
			struct {
				VkBuffer buffer;
				VkDeviceMemory memory;
			} vertexStaging, indexStaging;

			// Create staging buffers
			// Vertex data
			createBuffer(
				VK_BUFFER_USAGE_TRANSFER_SRC_BIT,
				VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT,
				vertexBufferSize,
				vertexBuffer.data(),
				&vertexStaging.buffer,
				&vertexStaging.memory);
			// Index data
			createBuffer(
				VK_BUFFER_USAGE_TRANSFER_SRC_BIT,
				VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT,
				indexBufferSize,
				indexBuffer.data(),
				&indexStaging.buffer,
				&indexStaging.memory);

			// Create device local buffers
			// Vertex buffer
			createBuffer(
				VK_BUFFER_USAGE_VERTEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT,
				VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT,
				vertexBufferSize,
				nullptr,
				&mesh.vertices.buf,
				&mesh.vertices.mem);
			// Index buffer
			createBuffer(
				VK_BUFFER_USAGE_INDEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT,
				VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT,
				indexBufferSize,
				nullptr,
				&mesh.indices.buf,
				&mesh.indices.mem);

			// Copy from staging buffers
			VkCommandBuffer copyCmd = VulkanExampleBase::createCommandBuffer(VK_COMMAND_BUFFER_LEVEL_PRIMARY, true);

			VkBufferCopy copyRegion = {};

			copyRegion.size = vertexBufferSize;
			vkCmdCopyBuffer(
				copyCmd,
				vertexStaging.buffer,
				mesh.vertices.buf,
				1,
				&copyRegion);

			copyRegion.size = indexBufferSize;
			vkCmdCopyBuffer(
				copyCmd,
				indexStaging.buffer,
				mesh.indices.buf,
				1,
				&copyRegion);

			VulkanExampleBase::flushCommandBuffer(copyCmd, queue, true);

			vkDestroyBuffer(device, vertexStaging.buffer, nullptr);
			vkFreeMemory(device, vertexStaging.memory, nullptr);
			vkDestroyBuffer(device, indexStaging.buffer, nullptr);
			vkFreeMemory(device, indexStaging.memory, nullptr);
		}
		else
		{
			// Vertex buffer
			createBuffer(
				VK_BUFFER_USAGE_VERTEX_BUFFER_BIT,
				VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT,
				vertexBufferSize,
				vertexBuffer.data(),
				&mesh.vertices.buf,
				&mesh.vertices.mem);
			// Index buffer
			createBuffer(
				VK_BUFFER_USAGE_INDEX_BUFFER_BIT,
				VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT,
				indexBufferSize,
				indexBuffer.data(),
				&mesh.indices.buf,
				&mesh.indices.mem);
		}

		delete(meshLoader);
	}

	void loadTextures()
	{
		textureLoader->loadTexture(
			getAssetPath() + "models/voyager/voyager.ktx",
			VK_FORMAT_BC3_UNORM_BLOCK,
			&textures.colorMap);
	}

	void setupVertexDescriptions()
	{
		// Binding description
		vertices.bindingDescriptions.resize(1);
		vertices.bindingDescriptions[0] =
			vkTools::initializers::vertexInputBindingDescription(
				VERTEX_BUFFER_BIND_ID,
				sizeof(Vertex),
				VK_VERTEX_INPUT_RATE_VERTEX);

		// Attribute descriptions
		// Describes memory layout and shader positions
		vertices.attributeDescriptions.resize(4);
		// Location 0 : Position
		vertices.attributeDescriptions[0] =
			vkTools::initializers::vertexInputAttributeDescription(
				VERTEX_BUFFER_BIND_ID,
				0,
				VK_FORMAT_R32G32B32_SFLOAT,
				0);
		// Location 1 : Normal
		vertices.attributeDescriptions[1] =
			vkTools::initializers::vertexInputAttributeDescription(
				VERTEX_BUFFER_BIND_ID,
				1,
				VK_FORMAT_R32G32B32_SFLOAT,
				sizeof(float) * 3);
		// Location 2 : Texture coordinates
		vertices.attributeDescriptions[2] =
			vkTools::initializers::vertexInputAttributeDescription(
				VERTEX_BUFFER_BIND_ID,
				2,
				VK_FORMAT_R32G32_SFLOAT,
				sizeof(float) * 6);
		// Location 3 : Color
		vertices.attributeDescriptions[3] =
			vkTools::initializers::vertexInputAttributeDescription(
				VERTEX_BUFFER_BIND_ID,
				3,
				VK_FORMAT_R32G32B32_SFLOAT,
				sizeof(float) * 8);

		vertices.inputState = vkTools::initializers::pipelineVertexInputStateCreateInfo();
		vertices.inputState.vertexBindingDescriptionCount = vertices.bindingDescriptions.size();
		vertices.inputState.pVertexBindingDescriptions = vertices.bindingDescriptions.data();
		vertices.inputState.vertexAttributeDescriptionCount = vertices.attributeDescriptions.size();
		vertices.inputState.pVertexAttributeDescriptions = vertices.attributeDescriptions.data();
	}

	void setupDescriptorPool()
	{
		// Example uses one ubo and one combined image sampler
		std::vector<VkDescriptorPoolSize> poolSizes =
		{
			vkTools::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1),
			vkTools::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1),
		};

		VkDescriptorPoolCreateInfo descriptorPoolInfo =
			vkTools::initializers::descriptorPoolCreateInfo(
				poolSizes.size(),
				poolSizes.data(),
				1);

		VK_CHECK_RESULT(vkCreateDescriptorPool(device, &descriptorPoolInfo, nullptr, &descriptorPool));
	}

	void setupDescriptorSetLayout()
	{
		std::vector<VkDescriptorSetLayoutBinding> setLayoutBindings =
		{
			// Binding 0 : Vertex shader uniform buffer
			vkTools::initializers::descriptorSetLayoutBinding(
			VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER,
				VK_SHADER_STAGE_VERTEX_BIT,
				0),
			// Binding 1 : Fragment shader combined sampler
			vkTools::initializers::descriptorSetLayoutBinding(
				VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
				VK_SHADER_STAGE_FRAGMENT_BIT,
				1),
		};

		VkDescriptorSetLayoutCreateInfo descriptorLayout =
			vkTools::initializers::descriptorSetLayoutCreateInfo(
				setLayoutBindings.data(),
				setLayoutBindings.size());

		VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorLayout, nullptr, &descriptorSetLayout));

		VkPipelineLayoutCreateInfo pPipelineLayoutCreateInfo =
			vkTools::initializers::pipelineLayoutCreateInfo(
				&descriptorSetLayout,
				1);

		VK_CHECK_RESULT(vkCreatePipelineLayout(device, &pPipelineLayoutCreateInfo, nullptr, &pipelineLayout));
	}

	void setupDescriptorSet()
	{
		VkDescriptorSetAllocateInfo allocInfo =
			vkTools::initializers::descriptorSetAllocateInfo(
				descriptorPool,
				&descriptorSetLayout,
				1);

		VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorSet));

		VkDescriptorImageInfo texDescriptor =
			vkTools::initializers::descriptorImageInfo(
				textures.colorMap.sampler,
				textures.colorMap.view,
				VK_IMAGE_LAYOUT_GENERAL);

		std::vector<VkWriteDescriptorSet> writeDescriptorSets =
		{
			// Binding 0 : Vertex shader uniform buffer
			vkTools::initializers::writeDescriptorSet(
			descriptorSet,
				VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER,
				0,
				&uniformData.vsScene.descriptor),
			// Binding 1 : Color map 
			vkTools::initializers::writeDescriptorSet(
				descriptorSet,
				VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
				1,
				&texDescriptor)
		};

		vkUpdateDescriptorSets(device, writeDescriptorSets.size(), writeDescriptorSets.data(), 0, NULL);
	}

	void preparePipelines()
	{
		VkPipelineInputAssemblyStateCreateInfo inputAssemblyState =
			vkTools::initializers::pipelineInputAssemblyStateCreateInfo(
				VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST,
				0,
				VK_FALSE);

		VkPipelineRasterizationStateCreateInfo rasterizationState =
			vkTools::initializers::pipelineRasterizationStateCreateInfo(
				VK_POLYGON_MODE_FILL,
				VK_CULL_MODE_BACK_BIT,
				VK_FRONT_FACE_CLOCKWISE,
				0);

		VkPipelineColorBlendAttachmentState blendAttachmentState =
			vkTools::initializers::pipelineColorBlendAttachmentState(
				0xf,
				VK_FALSE);

		VkPipelineColorBlendStateCreateInfo colorBlendState =
			vkTools::initializers::pipelineColorBlendStateCreateInfo(
				1,
				&blendAttachmentState);

		VkPipelineDepthStencilStateCreateInfo depthStencilState =
			vkTools::initializers::pipelineDepthStencilStateCreateInfo(
				VK_TRUE,
				VK_TRUE,
				VK_COMPARE_OP_LESS_OR_EQUAL);

		VkPipelineViewportStateCreateInfo viewportState =
			vkTools::initializers::pipelineViewportStateCreateInfo(1, 1, 0);

		VkPipelineMultisampleStateCreateInfo multisampleState =
			vkTools::initializers::pipelineMultisampleStateCreateInfo(
				VK_SAMPLE_COUNT_1_BIT,
				0);

		std::vector<VkDynamicState> dynamicStateEnables = {
			VK_DYNAMIC_STATE_VIEWPORT,
			VK_DYNAMIC_STATE_SCISSOR
		};
		VkPipelineDynamicStateCreateInfo dynamicState =
			vkTools::initializers::pipelineDynamicStateCreateInfo(
				dynamicStateEnables.data(),
				dynamicStateEnables.size(),
				0);

		// Solid rendering pipeline
		// Load shaders
		std::array<VkPipelineShaderStageCreateInfo, 2> shaderStages;

		shaderStages[0] = loadShader(getAssetPath() + "shaders/mesh/mesh.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
		shaderStages[1] = loadShader(getAssetPath() + "shaders/mesh/mesh.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);

		VkGraphicsPipelineCreateInfo pipelineCreateInfo =
			vkTools::initializers::pipelineCreateInfo(
				pipelineLayout,
				renderPass,
				0);

		pipelineCreateInfo.pVertexInputState = &vertices.inputState;
		pipelineCreateInfo.pInputAssemblyState = &inputAssemblyState;
		pipelineCreateInfo.pRasterizationState = &rasterizationState;
		pipelineCreateInfo.pColorBlendState = &colorBlendState;
		pipelineCreateInfo.pMultisampleState = &multisampleState;
		pipelineCreateInfo.pViewportState = &viewportState;
		pipelineCreateInfo.pDepthStencilState = &depthStencilState;
		pipelineCreateInfo.pDynamicState = &dynamicState;
		pipelineCreateInfo.stageCount = shaderStages.size();
		pipelineCreateInfo.pStages = shaderStages.data();

		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCreateInfo, nullptr, &pipelines.solid));

		// Wire frame rendering pipeline
		rasterizationState.polygonMode = VK_POLYGON_MODE_LINE;
		rasterizationState.lineWidth = 1.0f;

		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCreateInfo, nullptr, &pipelines.wireframe));
	}

	// Prepare and initialize uniform buffer containing shader uniforms
	void prepareUniformBuffers()
	{
		// Vertex shader uniform buffer block
		createBuffer(
			VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT,
			VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT,
			sizeof(uboVS),
			nullptr,
			&uniformData.vsScene.buffer,
			&uniformData.vsScene.memory,
			&uniformData.vsScene.descriptor);

		updateUniformBuffers();
	}

	void updateUniformBuffers()
	{
		uboVS.projection = glm::perspective(glm::radians(60.0f), (float)width / (float)height, 0.1f, 256.0f);
		glm::mat4 viewMatrix = glm::translate(glm::mat4(), glm::vec3(0.0f, 0.0f, zoom));

		uboVS.model = viewMatrix * glm::translate(glm::mat4(), cameraPos);
		uboVS.model = glm::rotate(uboVS.model, glm::radians(rotation.x), glm::vec3(1.0f, 0.0f, 0.0f));
		uboVS.model = glm::rotate(uboVS.model, glm::radians(rotation.y), glm::vec3(0.0f, 1.0f, 0.0f));
		uboVS.model = glm::rotate(uboVS.model, glm::radians(rotation.z), glm::vec3(0.0f, 0.0f, 1.0f));

		uint8_t *pData;
		VK_CHECK_RESULT(vkMapMemory(device, uniformData.vsScene.memory, 0, sizeof(uboVS), 0, (void **)&pData));
		memcpy(pData, &uboVS, sizeof(uboVS));
		vkUnmapMemory(device, uniformData.vsScene.memory);
	}

	void draw()
	{
		VulkanExampleBase::prepareFrame();

		// Command buffer to be sumitted to the queue
		submitInfo.commandBufferCount = 1;
		submitInfo.pCommandBuffers = &drawCmdBuffers[currentBuffer];

		// Submit to queue
		VK_CHECK_RESULT(vkQueueSubmit(queue, 1, &submitInfo, VK_NULL_HANDLE));

		VulkanExampleBase::submitFrame();
	}

	void prepare()
	{
		VulkanExampleBase::prepare();
		loadTextures();
		loadMesh();
		setupVertexDescriptions();
		prepareUniformBuffers();
		setupDescriptorSetLayout();
		preparePipelines();
		setupDescriptorPool();
		setupDescriptorSet();
		buildCommandBuffers();
		prepared = true;
	}

	virtual void render()
	{
		if (!prepared)
			return;
		draw();
	}

	virtual void viewChanged()
	{
		updateUniformBuffers();
	}

	virtual void keyPressed(uint32_t keyCode)
	{
		switch (keyCode)
		{
		case KEY_W:
		case GAMEPAD_BUTTON_A:
			wireframe = !wireframe;
			reBuildCommandBuffers();
			break;
		}
	}

	virtual void getOverlayText(VulkanTextOverlay *textOverlay)
	{
#if defined(__ANDROID__)
		textOverlay->addText("Press \"Button A\" to toggle wireframe", 5.0f, 85.0f, VulkanTextOverlay::alignLeft);
#else
		textOverlay->addText("Press \"w\" to toggle wireframe", 5.0f, 85.0f, VulkanTextOverlay::alignLeft);
#endif
	}
};

VULKAN_EXAMPLE_MAIN()