/*
* 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)
*/

#include "VulkanTools.h"

const std::string getAssetPath()
{
#if defined(VK_USE_PLATFORM_ANDROID_KHR)
	return "";
#elif defined(VK_EXAMPLE_DATA_DIR)
	return VK_EXAMPLE_DATA_DIR;
#else
	return "./../data/";
#endif
}

namespace vks
{
	namespace tools
	{
		bool errorModeSilent = false;

		std::string errorString(VkResult errorCode)
		{
			switch (errorCode)
			{
#define STR(r) case VK_ ##r: return #r
				STR(NOT_READY);
				STR(TIMEOUT);
				STR(EVENT_SET);
				STR(EVENT_RESET);
				STR(INCOMPLETE);
				STR(ERROR_OUT_OF_HOST_MEMORY);
				STR(ERROR_OUT_OF_DEVICE_MEMORY);
				STR(ERROR_INITIALIZATION_FAILED);
				STR(ERROR_DEVICE_LOST);
				STR(ERROR_MEMORY_MAP_FAILED);
				STR(ERROR_LAYER_NOT_PRESENT);
				STR(ERROR_EXTENSION_NOT_PRESENT);
				STR(ERROR_FEATURE_NOT_PRESENT);
				STR(ERROR_INCOMPATIBLE_DRIVER);
				STR(ERROR_TOO_MANY_OBJECTS);
				STR(ERROR_FORMAT_NOT_SUPPORTED);
				STR(ERROR_SURFACE_LOST_KHR);
				STR(ERROR_NATIVE_WINDOW_IN_USE_KHR);
				STR(SUBOPTIMAL_KHR);
				STR(ERROR_OUT_OF_DATE_KHR);
				STR(ERROR_INCOMPATIBLE_DISPLAY_KHR);
				STR(ERROR_VALIDATION_FAILED_EXT);
				STR(ERROR_INVALID_SHADER_NV);
#undef STR
			default:
				return "UNKNOWN_ERROR";
			}
		}

		std::string physicalDeviceTypeString(VkPhysicalDeviceType type)
		{
			switch (type)
			{
#define STR(r) case VK_PHYSICAL_DEVICE_TYPE_ ##r: return #r
				STR(OTHER);
				STR(INTEGRATED_GPU);
				STR(DISCRETE_GPU);
				STR(VIRTUAL_GPU);
#undef STR
			default: return "UNKNOWN_DEVICE_TYPE";
			}
		}

		VkBool32 getSupportedDepthFormat(VkPhysicalDevice physicalDevice, VkFormat *depthFormat)
		{
			// Since all depth formats may be optional, we need to find a suitable depth format to use
			// Start with the highest precision packed format
			std::vector<VkFormat> depthFormats = {
				VK_FORMAT_D32_SFLOAT_S8_UINT,
				VK_FORMAT_D32_SFLOAT,
				VK_FORMAT_D24_UNORM_S8_UINT,
				VK_FORMAT_D16_UNORM_S8_UINT,
				VK_FORMAT_D16_UNORM
			};

			for (auto& format : depthFormats)
			{
				VkFormatProperties formatProps;
				vkGetPhysicalDeviceFormatProperties(physicalDevice, format, &formatProps);
				// Format must support depth stencil attachment for optimal tiling
				if (formatProps.optimalTilingFeatures & VK_FORMAT_FEATURE_DEPTH_STENCIL_ATTACHMENT_BIT)
				{
					*depthFormat = format;
					return true;
				}
			}

			return false;
		}

		// Create an image memory barrier for changing the layout of
		// an image and put it into an active command buffer
		// See chapter 11.4 "Image Layout" for details

		void setImageLayout(
			VkCommandBuffer cmdbuffer,
			VkImage image,
			VkImageLayout oldImageLayout,
			VkImageLayout newImageLayout,
			VkImageSubresourceRange subresourceRange,
			VkPipelineStageFlags srcStageMask,
			VkPipelineStageFlags dstStageMask)
		{
			// Create an image barrier object
			VkImageMemoryBarrier imageMemoryBarrier = vks::initializers::imageMemoryBarrier();
			imageMemoryBarrier.oldLayout = oldImageLayout;
			imageMemoryBarrier.newLayout = newImageLayout;
			imageMemoryBarrier.image = image;
			imageMemoryBarrier.subresourceRange = subresourceRange;

			// Source layouts (old)
			// Source access mask controls actions that have to be finished on the old layout
			// before it will be transitioned to the new layout
			switch (oldImageLayout)
			{
			case VK_IMAGE_LAYOUT_UNDEFINED:
				// Image layout is undefined (or does not matter)
				// Only valid as initial layout
				// No flags required, listed only for completeness
				imageMemoryBarrier.srcAccessMask = 0;
				break;

			case VK_IMAGE_LAYOUT_PREINITIALIZED:
				// Image is preinitialized
				// Only valid as initial layout for linear images, preserves memory contents
				// Make sure host writes have been finished
				imageMemoryBarrier.srcAccessMask = VK_ACCESS_HOST_WRITE_BIT;
				break;

			case VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL:
				// Image is a color attachment
				// Make sure any writes to the color buffer have been finished
				imageMemoryBarrier.srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
				break;

			case VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL:
				// Image is a depth/stencil attachment
				// Make sure any writes to the depth/stencil buffer have been finished
				imageMemoryBarrier.srcAccessMask = VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT;
				break;

			case VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL:
				// Image is a transfer source 
				// Make sure any reads from the image have been finished
				imageMemoryBarrier.srcAccessMask = VK_ACCESS_TRANSFER_READ_BIT;
				break;

			case VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL:
				// Image is a transfer destination
				// Make sure any writes to the image have been finished
				imageMemoryBarrier.srcAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
				break;

			case VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL:
				// Image is read by a shader
				// Make sure any shader reads from the image have been finished
				imageMemoryBarrier.srcAccessMask = VK_ACCESS_SHADER_READ_BIT;
				break;
			default:
				// Other source layouts aren't handled (yet)
				break;
			}

			// Target layouts (new)
			// Destination access mask controls the dependency for the new image layout
			switch (newImageLayout)
			{
			case VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL:
				// Image will be used as a transfer destination
				// Make sure any writes to the image have been finished
				imageMemoryBarrier.dstAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
				break;

			case VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL:
				// Image will be used as a transfer source
				// Make sure any reads from the image have been finished
				imageMemoryBarrier.dstAccessMask = VK_ACCESS_TRANSFER_READ_BIT;
				break;

			case VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL:
				// Image will be used as a color attachment
				// Make sure any writes to the color buffer have been finished
				imageMemoryBarrier.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
				break;

			case VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL:
				// Image layout will be used as a depth/stencil attachment
				// Make sure any writes to depth/stencil buffer have been finished
				imageMemoryBarrier.dstAccessMask = imageMemoryBarrier.dstAccessMask | VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT;
				break;

			case VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL:
				// Image will be read in a shader (sampler, input attachment)
				// Make sure any writes to the image have been finished
				if (imageMemoryBarrier.srcAccessMask == 0)
				{
					imageMemoryBarrier.srcAccessMask = VK_ACCESS_HOST_WRITE_BIT | VK_ACCESS_TRANSFER_WRITE_BIT;
				}
				imageMemoryBarrier.dstAccessMask = VK_ACCESS_SHADER_READ_BIT;
				break;
			default:
				// Other source layouts aren't handled (yet)
				break;
			}

			// Put barrier inside setup command buffer
			vkCmdPipelineBarrier(
				cmdbuffer,
				srcStageMask,
				dstStageMask,
				0,
				0, nullptr,
				0, nullptr,
				1, &imageMemoryBarrier);
		}

		// Fixed sub resource on first mip level and layer
		void setImageLayout(
			VkCommandBuffer cmdbuffer,
			VkImage image,
			VkImageAspectFlags aspectMask,
			VkImageLayout oldImageLayout,
			VkImageLayout newImageLayout,
			VkPipelineStageFlags srcStageMask,
			VkPipelineStageFlags dstStageMask)
		{
			VkImageSubresourceRange subresourceRange = {};
			subresourceRange.aspectMask = aspectMask;
			subresourceRange.baseMipLevel = 0;
			subresourceRange.levelCount = 1;
			subresourceRange.layerCount = 1;
			setImageLayout(cmdbuffer, image, oldImageLayout, newImageLayout, subresourceRange, srcStageMask, dstStageMask);
		}

		void insertImageMemoryBarrier(
			VkCommandBuffer cmdbuffer,
			VkImage image,
			VkAccessFlags srcAccessMask,
			VkAccessFlags dstAccessMask,
			VkImageLayout oldImageLayout,
			VkImageLayout newImageLayout,
			VkPipelineStageFlags srcStageMask,
			VkPipelineStageFlags dstStageMask,
			VkImageSubresourceRange subresourceRange)
		{
			VkImageMemoryBarrier imageMemoryBarrier = vks::initializers::imageMemoryBarrier();
			imageMemoryBarrier.srcAccessMask = srcAccessMask;
			imageMemoryBarrier.dstAccessMask = dstAccessMask;
			imageMemoryBarrier.oldLayout = oldImageLayout;
			imageMemoryBarrier.newLayout = newImageLayout;
			imageMemoryBarrier.image = image;
			imageMemoryBarrier.subresourceRange = subresourceRange;

			vkCmdPipelineBarrier(
				cmdbuffer,
				srcStageMask,
				dstStageMask,
				0,
				0, nullptr,
				0, nullptr,
				1, &imageMemoryBarrier);
		}

		void exitFatal(std::string message, int32_t exitCode)
		{
#if defined(_WIN32)
			if (!errorModeSilent) {
				MessageBox(NULL, message.c_str(), NULL, MB_OK | MB_ICONERROR);
			}
#elif defined(__ANDROID__)
            LOGE("Fatal error: %s", message.c_str());
			//vks::android::showAlert(message.c_str());
#endif
			std::cerr << message << "\n";
#if !defined(__ANDROID__)
			exit(exitCode);
#endif
		}

		void exitFatal(std::string message, VkResult resultCode)
		{
			exitFatal(message, (int32_t)resultCode);
		}

#if defined(__ANDROID__)
		// Android shaders are stored as assets in the apk
		// So they need to be loaded via the asset manager
		VkShaderModule loadShader(AAssetManager* assetManager, const char *fileName, VkDevice device)
		{
			// Load shader from compressed asset
			AAsset* asset = AAssetManager_open(assetManager, fileName, AASSET_MODE_STREAMING);
			assert(asset);
			size_t size = AAsset_getLength(asset);
			assert(size > 0);

			char *shaderCode = new char[size];
			AAsset_read(asset, shaderCode, size);
			AAsset_close(asset);

			VkShaderModule shaderModule;
			VkShaderModuleCreateInfo moduleCreateInfo;
			moduleCreateInfo.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
			moduleCreateInfo.pNext = NULL;
			moduleCreateInfo.codeSize = size;
			moduleCreateInfo.pCode = (uint32_t*)shaderCode;
			moduleCreateInfo.flags = 0;

			VK_CHECK_RESULT(vkCreateShaderModule(device, &moduleCreateInfo, NULL, &shaderModule));

			delete[] shaderCode;

			return shaderModule;
		}
#else
		VkShaderModule loadShader(const char *fileName, VkDevice device)
		{
			std::ifstream is(fileName, std::ios::binary | std::ios::in | std::ios::ate);

			if (is.is_open())
			{
				size_t size = is.tellg();
				is.seekg(0, std::ios::beg);
				char* shaderCode = new char[size];
				is.read(shaderCode, size);
				is.close();

				assert(size > 0);

				VkShaderModule shaderModule;
				VkShaderModuleCreateInfo moduleCreateInfo{};
				moduleCreateInfo.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
				moduleCreateInfo.codeSize = size;
				moduleCreateInfo.pCode = (uint32_t*)shaderCode;

				VK_CHECK_RESULT(vkCreateShaderModule(device, &moduleCreateInfo, NULL, &shaderModule));

				delete[] shaderCode;

				return shaderModule;
			}
			else
			{
				std::cerr << "Error: Could not open shader file \"" << fileName << "\"" << std::endl;
				return VK_NULL_HANDLE;
			}
		}
#endif

		bool fileExists(const std::string &filename)
		{
			std::ifstream f(filename.c_str());
			return !f.fail();
		}
	}
}