#pragma once
#include "DX12Buffer.h"

#include "d3dx12.h"
#include "DX12CommandQueue.h"

using namespace Framework;

// Constructor
// eSize: length of an element in bytes
DX12Buffer::DX12Buffer(
    int eSize, ID3D12Device5* zDevice, DX12CommandQueue* queue, int flags)
    : DXBuffer(eSize),
      buffer(0),
      zDevice(zDevice),
      queue(queue)
{
    description = new D3D12_RESOURCE_DESC();
    ZeroMemory(description, sizeof(D3D12_RESOURCE_DESC));
    description->Dimension = D3D12_RESOURCE_DIMENSION_BUFFER;
    description->Alignment = 0;
    description->Height = 1;
    description->DepthOrArraySize = 1;
    description->MipLevels = 1;
    description->Format = DXGI_FORMAT_UNKNOWN;
    description->SampleDesc.Count = 1;
    description->Layout = D3D12_TEXTURE_LAYOUT_ROW_MAJOR;
    description->Flags = (D3D12_RESOURCE_FLAGS)flags;
}

// Destructor
DX12Buffer::~DX12Buffer()
{
    if (buffer) buffer->Release();
    if (queue) queue->release();
    delete description;
}

// Copies the data into the buffer if it has changed
void DX12Buffer::copyToGPU(__int64 byteCount)
{
    if (!len) return;
    if (byteCount < 0) byteCount = len;
    if (description->Width != (unsigned)len)
    {
        if (buffer) buffer->Release();
        buffer = 0;
        description->Width = (unsigned)len;
    }
    if (!buffer)
    {
        D3D12_HEAP_PROPERTIES hprop;
        hprop.Type = D3D12_HEAP_TYPE_UPLOAD;
        hprop.CPUPageProperty = D3D12_CPU_PAGE_PROPERTY_UNKNOWN;
        hprop.MemoryPoolPreference = D3D12_MEMORY_POOL_UNKNOWN;
        hprop.CreationNodeMask = 1;
        hprop.VisibleNodeMask = 1;
        zDevice->CreateCommittedResource(&hprop,
            D3D12_HEAP_FLAG_NONE,
            description,
            D3D12_RESOURCE_STATE_GENERIC_READ,
            0,
            __uuidof(ID3D12Resource),
            (void**)&buffer);
    }
    if (changed && data)
    {
        BYTE* pData;
        D3D12_RANGE r;
        r.Begin = 0;
        r.End = 0;
        buffer->Map(0, &r, (void**)&pData);
        memcpy(pData, data, byteCount);
        r.End = byteCount;
        buffer->Unmap(0, &r);
        changed = 0;
    }
}

void Framework::DX12Buffer::createBufferWithoutData(
    D3D12_RESOURCE_STATES states, D3D12_HEAP_TYPE heapType)
{
    if (!len) return;
    if (description->Width != len)
    {
        if (buffer) buffer->Release();
        buffer = 0;
        description->Width = len;
    }
    if (!buffer)
    {
        D3D12_HEAP_PROPERTIES hprop;
        hprop.Type = heapType;
        hprop.CPUPageProperty = D3D12_CPU_PAGE_PROPERTY_UNKNOWN;
        hprop.MemoryPoolPreference = D3D12_MEMORY_POOL_UNKNOWN;
        hprop.CreationNodeMask = 0;
        hprop.VisibleNodeMask = 0;
        zDevice->CreateCommittedResource(&hprop,
            D3D12_HEAP_FLAG_NONE,
            description,
            states & ~D3D12_RESOURCE_STATE_UNORDERED_ACCESS,
            0,
            __uuidof(ID3D12Resource),
            (void**)&buffer);
        if (states & D3D12_RESOURCE_STATE_UNORDERED_ACCESS)
        {
            // TODO: add state transition
            CD3DX12_RESOURCE_BARRIER transition
                = CD3DX12_RESOURCE_BARRIER::Transition(
                    buffer, D3D12_RESOURCE_STATE_COMMON, states);
            queue->zCommandList()->ResourceBarrier(1, &transition);
        }
    }
}

// Returns the buffer
ID3D12Resource* DX12Buffer::zBuffer() const
{
    return buffer;
}