/*
Crafter®.Graphics
Copyright (C) 2026 Catcrafts®
catcrafts.net

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License version 3.0 as published by the Free Software Foundation;

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
*/

module;

#ifdef CRAFTER_GRAPHICS_VULKAN
#include <vulkan/vulkan.h>
#endif

export module Crafter.Graphics:VulkanBuffer;
#ifdef CRAFTER_GRAPHICS_VULKAN
import std;
import :VulkanDevice;

namespace Crafter {
    export template <typename T>
    class VulkanBuffer {
    public:
        T* value;
        VkDescriptorBufferInfo descriptor;
        VkDeviceSize alignment = 0;
		VkMemoryPropertyFlags memoryPropertyFlags;
        VkBufferUsageFlags usageFlags;
        VkBuffer buffer = VK_NULL_HANDLE;
        VkDeviceMemory memory = VK_NULL_HANDLE;
        VkDeviceAddress address;
    public:
        VulkanBuffer() : value(nullptr) {};
        VulkanBuffer(VkBufferUsageFlags usageFlags, VkMemoryPropertyFlags memoryPropertyFlags, std::uint32_t count = 1) {
            VkBufferCreateInfo bufferCreateInfo {};
			bufferCreateInfo.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
            bufferCreateInfo.usage = usageFlags;
			bufferCreateInfo.size = sizeof(T)*count;
            VulkanDevice::CheckVkResult(vkCreateBuffer(VulkanDevice::device, &bufferCreateInfo, nullptr, &buffer));
        
            // Create the memory backing up the buffer handle
            VkMemoryRequirements memReqs;
            VkMemoryAllocateInfo memAlloc {};
			memAlloc.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
            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::CheckVkResult(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::CheckVkResult(vkBindBufferMemory(VulkanDevice::device, buffer, memory, 0));
            if(memoryPropertyFlags & VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT) {
                VulkanDevice::CheckVkResult(vkMapMemory(VulkanDevice::device, memory, 0, sizeof(T)*count, 0, reinterpret_cast<void**>(&value)));
            }

            VkBufferDeviceAddressInfo addressInfo = {
                .sType = VK_STRUCTURE_TYPE_BUFFER_DEVICE_ADDRESS_INFO,
                .buffer = buffer
            };

            address = vkGetBufferDeviceAddress(VulkanDevice::device, &addressInfo);
        }
        ~VulkanBuffer() {
            if(value != nullptr) {
                if(memoryPropertyFlags & VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT) {
                    vkUnmapMemory(VulkanDevice::device, memory);
                }
                vkDestroyBuffer(VulkanDevice::device, buffer, nullptr);
                vkFreeMemory(VulkanDevice::device, memory, nullptr);
            }
        }
    };
}
#endif