module;

#include <cstdint>
#include <vulkan/vulkan.h>
#include "VulkanInitializers.hpp"

export module Crafter.Graphics:VulkanBuffer;
import :VulkanDevice;

namespace Crafter {
    export template <typename T>
    class Buffer {
    public:
        T* value;
        VkDescriptorBufferInfo descriptor;
        Buffer(VkBufferUsageFlags usageFlags, VkMemoryPropertyFlags memoryPropertyFlags, std::uint32_t count = 1) {
            VkBufferCreateInfo bufferCreateInfo = vks::initializers::bufferCreateInfo(usageFlags, sizeof(T)*count);
            VulkanDevice::CHECK_VK_RESULT(vkCreateBuffer(VulkanDevice::device, &bufferCreateInfo, nullptr, &buffer));
        
            // Create the memory backing up the buffer handle
            VkMemoryRequirements memReqs;
            VkMemoryAllocateInfo memAlloc = vks::initializers::memoryAllocateInfo();
            vkGetBufferMemoryRequirements(VulkanDevice::device, buffer, &memReqs);
            memAlloc.allocationSize = memReqs.size;
            // Find a memory type index that fits the properties of the buffer
            memAlloc.memoryTypeIndex = VulkanDevice::GetMemoryType(memReqs.memoryTypeBits, memoryPropertyFlags);
            // If the buffer has VK_BUFFER_USAGE_SHADER_DEVICE_ADDRESS_BIT set we also need to enable the appropriate flag during allocation
            VkMemoryAllocateFlagsInfoKHR allocFlagsInfo{};
            if (usageFlags & VK_BUFFER_USAGE_SHADER_DEVICE_ADDRESS_BIT) {
                allocFlagsInfo.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_FLAGS_INFO_KHR;
                allocFlagsInfo.flags = VK_MEMORY_ALLOCATE_DEVICE_ADDRESS_BIT_KHR;
                memAlloc.pNext = &allocFlagsInfo;
            }
            VulkanDevice::CHECK_VK_RESULT(vkAllocateMemory(VulkanDevice::device, &memAlloc, nullptr, &memory));
        
            alignment = memReqs.alignment;
            usageFlags = usageFlags;
            memoryPropertyFlags = memoryPropertyFlags;
        
            descriptor.offset = 0;
            descriptor.buffer = buffer;
            descriptor.range = sizeof(T)*count;
        
            VulkanDevice::CHECK_VK_RESULT(vkBindBufferMemory(VulkanDevice::device, buffer, memory, 0));
            VulkanDevice::CHECK_VK_RESULT(vkMapMemory(VulkanDevice::device, memory, 0, sizeof(T)*count, 0, reinterpret_cast<void**>(&value)));
        }
    private:
        VkBuffer buffer = VK_NULL_HANDLE;
        VkDeviceMemory memory = VK_NULL_HANDLE;
        VkDeviceSize alignment = 0;
		VkMemoryPropertyFlags memoryPropertyFlags;
        VkBufferUsageFlags usageFlags;
    };
}