// IAEngine: 2D Game Engine by IA
// Copyright (C) 2025 IASoft (PVT) LTD (oss@iasoft.dev)
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

#include <RenderCore/Buffer.hpp>

namespace ia::iae
{
    RDC_Buffer::RDC_Buffer() : m_type(EType::NONE), m_size(0)
    {
    }

    RDC_Buffer::RDC_Buffer(IN EType type, IN UINT32 size) : m_type(type), m_size(size)
    {
    }

    RDC_StagingBuffer::RDC_StagingBuffer(IN UINT32 size) : RDC_Buffer(EType::NONE, size)
    {
        SDL_GPUTransferBufferCreateInfo stagingBufferCreateInfo{.usage = SDL_GPU_TRANSFERBUFFERUSAGE_UPLOAD,
                                                                .size = size};
        m_buffer = SDL_CreateGPUTransferBuffer(RDC_Device::GetHandle(), &stagingBufferCreateInfo);
    }

    RDC_StagingBuffer::~RDC_StagingBuffer()
    {
        SDL_ReleaseGPUTransferBuffer(RDC_Device::GetHandle(), m_buffer);
    }

    VOID RDC_StagingBuffer::CopyFrom(IN PCVOID data, IN UINT32 size)
    {
        IA_ASSERT(size <= m_size);
        const auto mappedPtr = SDL_MapGPUTransferBuffer(RDC_Device::GetHandle(), m_buffer, false);
        SDL_memcpy(mappedPtr, data, size);
        SDL_UnmapGPUTransferBuffer(RDC_Device::GetHandle(), m_buffer);
    }

    RDC_DeviceLocalBuffer::RDC_DeviceLocalBuffer()
    {
    }

    RDC_DeviceLocalBuffer::RDC_DeviceLocalBuffer(IN RDC_Buffer::EType type, IN UINT32 size) : RDC_Buffer(type, size)
    {
        SDL_GPUBufferCreateInfo createInfo{.size = size};
        switch (type)
        {
        case RDC_Buffer::EType::NONE:
            THROW_INVALID_DATA();
            break;

        case RDC_Buffer::EType::VERTEX:
            createInfo.usage = SDL_GPU_BUFFERUSAGE_VERTEX;
            break;

        case RDC_Buffer::EType::INDEX:
            createInfo.usage = SDL_GPU_BUFFERUSAGE_INDEX;
            break;

        case RDC_Buffer::EType::STORAGE:
            createInfo.usage = SDL_GPU_BUFFERUSAGE_GRAPHICS_STORAGE_READ;
            break;
        }
        m_buffer = SDL_CreateGPUBuffer(RDC_Device::GetHandle(), &createInfo);
    }

    RDC_DeviceLocalBuffer::~RDC_DeviceLocalBuffer()
    {
        if (m_buffer)
            SDL_ReleaseGPUBuffer(RDC_Device::GetHandle(), m_buffer);
    }

    VOID RDC_DeviceLocalBuffer::CopyFrom(IN RDC_StagingBuffer *stagingBuffer, IN UINT32 size)
    {
        CopyFrom(stagingBuffer->m_buffer, size);
    }

    VOID RDC_DeviceLocalBuffer::CopyFrom(IN SDL_GPUTransferBuffer *stagingBuffer, IN UINT32 size)
    {
        const auto cmdBuffer = SDL_AcquireGPUCommandBuffer(RDC_Device::GetHandle());
        const auto copyPass = SDL_BeginGPUCopyPass(cmdBuffer);

        SDL_GPUTransferBufferLocation src{.transfer_buffer = stagingBuffer, .offset = 0};
        SDL_GPUBufferRegion dst{.buffer = m_buffer, .offset = 0, .size = size};
        SDL_UploadToGPUBuffer(copyPass, &src, &dst, false);

        SDL_EndGPUCopyPass(copyPass);
        SDL_SubmitGPUCommandBuffer(cmdBuffer);
        SDL_WaitForGPUIdle(RDC_Device::GetHandle());
    }

    RDC_HostVisibleBuffer::RDC_HostVisibleBuffer(IN RDC_Buffer::EType type, IN UINT32 size)
        : RDC_DeviceLocalBuffer(type, size)
    {
        SDL_GPUTransferBufferCreateInfo stagingBufferCreateInfo{.usage = SDL_GPU_TRANSFERBUFFERUSAGE_UPLOAD,
                                                                .size = size};
        m_stagingBuffer = SDL_CreateGPUTransferBuffer(RDC_Device::GetHandle(), &stagingBufferCreateInfo);
    }

    RDC_HostVisibleBuffer::~RDC_HostVisibleBuffer()
    {
        SDL_ReleaseGPUTransferBuffer(RDC_Device::GetHandle(), m_stagingBuffer);
    }

    VOID RDC_HostVisibleBuffer::CopyFrom(IN PCVOID data, IN UINT32 size)
    {
        IA_ASSERT(size <= m_size);
        const auto mappedPtr = SDL_MapGPUTransferBuffer(RDC_Device::GetHandle(), m_stagingBuffer, false);
        SDL_memcpy(mappedPtr, data, size);
        SDL_UnmapGPUTransferBuffer(RDC_Device::GetHandle(), m_stagingBuffer);

        RDC_DeviceLocalBuffer::CopyFrom(m_stagingBuffer, size);
    }
} // namespace ia::iae