// Copyright 2016 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#include "VideoBackends/Vulkan/VertexManager.h"

#include "Common/CommonTypes.h"
#include "Common/Logging/Log.h"
#include "Common/MsgHandler.h"

#include "VideoBackends/Vulkan/BoundingBox.h"
#include "VideoBackends/Vulkan/CommandBufferManager.h"
#include "VideoBackends/Vulkan/FramebufferManager.h"
#include "VideoBackends/Vulkan/Renderer.h"
#include "VideoBackends/Vulkan/StateTracker.h"
#include "VideoBackends/Vulkan/StreamBuffer.h"
#include "VideoBackends/Vulkan/Util.h"
#include "VideoBackends/Vulkan/VertexFormat.h"
#include "VideoBackends/Vulkan/VulkanContext.h"

#include "VideoCommon/BoundingBox.h"
#include "VideoCommon/IndexGenerator.h"
#include "VideoCommon/Statistics.h"
#include "VideoCommon/VertexLoaderManager.h"
#include "VideoCommon/VideoConfig.h"

namespace Vulkan
{
// TODO: Clean up this mess
constexpr size_t INITIAL_VERTEX_BUFFER_SIZE = VertexManager::MAXVBUFFERSIZE * 2;
constexpr size_t MAX_VERTEX_BUFFER_SIZE = VertexManager::MAXVBUFFERSIZE * 16;
constexpr size_t INITIAL_INDEX_BUFFER_SIZE = VertexManager::MAXIBUFFERSIZE * sizeof(u16) * 2;
constexpr size_t MAX_INDEX_BUFFER_SIZE = VertexManager::MAXIBUFFERSIZE * sizeof(u16) * 16;

VertexManager::VertexManager()
    : m_cpu_vertex_buffer(MAXVBUFFERSIZE), m_cpu_index_buffer(MAXIBUFFERSIZE)
{
}

VertexManager::~VertexManager()
{
}

VertexManager* VertexManager::GetInstance()
{
  return static_cast<VertexManager*>(g_vertex_manager.get());
}

bool VertexManager::Initialize()
{
  m_vertex_stream_buffer = StreamBuffer::Create(VK_BUFFER_USAGE_VERTEX_BUFFER_BIT,
                                                INITIAL_VERTEX_BUFFER_SIZE, MAX_VERTEX_BUFFER_SIZE);

  m_index_stream_buffer = StreamBuffer::Create(VK_BUFFER_USAGE_INDEX_BUFFER_BIT,
                                               INITIAL_INDEX_BUFFER_SIZE, MAX_INDEX_BUFFER_SIZE);

  if (!m_vertex_stream_buffer || !m_index_stream_buffer)
  {
    PanicAlert("Failed to allocate streaming buffers");
    return false;
  }

  return true;
}

std::unique_ptr<NativeVertexFormat>
VertexManager::CreateNativeVertexFormat(const PortableVertexDeclaration& vtx_decl)
{
  return std::make_unique<VertexFormat>(vtx_decl);
}

void VertexManager::UploadUtilityUniforms(const void* uniforms, u32 uniforms_size)
{
  StateTracker::GetInstance()->UpdateConstants(uniforms, uniforms_size);
}

void VertexManager::ResetBuffer(u32 vertex_stride, bool cull_all)
{
  if (cull_all)
  {
    // Not drawing on the gpu, so store in a heap buffer instead
    m_cur_buffer_pointer = m_base_buffer_pointer = m_cpu_vertex_buffer.data();
    m_end_buffer_pointer = m_base_buffer_pointer + m_cpu_vertex_buffer.size();
    IndexGenerator::Start(m_cpu_index_buffer.data());
    return;
  }

  // Attempt to allocate from buffers
  bool has_vbuffer_allocation =
      m_vertex_stream_buffer->ReserveMemory(MAXVBUFFERSIZE, vertex_stride);
  bool has_ibuffer_allocation =
      m_index_stream_buffer->ReserveMemory(MAXIBUFFERSIZE * sizeof(u16), sizeof(u16));
  if (!has_vbuffer_allocation || !has_ibuffer_allocation)
  {
    // Flush any pending commands first, so that we can wait on the fences
    WARN_LOG(VIDEO, "Executing command list while waiting for space in vertex/index buffer");
    Util::ExecuteCurrentCommandsAndRestoreState(false);

    // Attempt to allocate again, this may cause a fence wait
    if (!has_vbuffer_allocation)
      has_vbuffer_allocation = m_vertex_stream_buffer->ReserveMemory(MAXVBUFFERSIZE, vertex_stride);
    if (!has_ibuffer_allocation)
      has_ibuffer_allocation =
          m_index_stream_buffer->ReserveMemory(MAXIBUFFERSIZE * sizeof(u16), sizeof(u16));

    // If we still failed, that means the allocation was too large and will never succeed, so panic
    if (!has_vbuffer_allocation || !has_ibuffer_allocation)
      PanicAlert("Failed to allocate space in streaming buffers for pending draw");
  }

  // Update pointers
  m_base_buffer_pointer = m_vertex_stream_buffer->GetHostPointer();
  m_end_buffer_pointer = m_vertex_stream_buffer->GetCurrentHostPointer() + MAXVBUFFERSIZE;
  m_cur_buffer_pointer = m_vertex_stream_buffer->GetCurrentHostPointer();
  IndexGenerator::Start(reinterpret_cast<u16*>(m_index_stream_buffer->GetCurrentHostPointer()));
}

void VertexManager::CommitBuffer(u32 num_vertices, u32 vertex_stride, u32 num_indices,
                                 u32* out_base_vertex, u32* out_base_index)
{
  const u32 vertex_data_size = num_vertices * vertex_stride;
  const u32 index_data_size = num_indices * sizeof(u16);

  *out_base_vertex =
      vertex_stride > 0 ?
          static_cast<u32>(m_vertex_stream_buffer->GetCurrentOffset() / vertex_stride) :
          0;
  *out_base_index = static_cast<u32>(m_index_stream_buffer->GetCurrentOffset() / sizeof(u16));

  m_vertex_stream_buffer->CommitMemory(vertex_data_size);
  m_index_stream_buffer->CommitMemory(index_data_size);

  ADDSTAT(stats.thisFrame.bytesVertexStreamed, static_cast<int>(vertex_data_size));
  ADDSTAT(stats.thisFrame.bytesIndexStreamed, static_cast<int>(index_data_size));

  StateTracker::GetInstance()->SetVertexBuffer(m_vertex_stream_buffer->GetBuffer(), 0);
  StateTracker::GetInstance()->SetIndexBuffer(m_index_stream_buffer->GetBuffer(), 0,
                                              VK_INDEX_TYPE_UINT16);
}

void VertexManager::UploadConstants()
{
  StateTracker::GetInstance()->UpdateVertexShaderConstants();
  StateTracker::GetInstance()->UpdateGeometryShaderConstants();
  StateTracker::GetInstance()->UpdatePixelShaderConstants();
}

void VertexManager::DrawCurrentBatch(u32 base_index, u32 num_indices, u32 base_vertex)
{
  // Flush all EFB pokes and invalidate the peek cache.
  FramebufferManager::GetInstance()->InvalidatePeekCache();
  FramebufferManager::GetInstance()->FlushEFBPokes();

  // If bounding box is enabled, we need to flush any changes first, then invalidate what we have.
  if (g_vulkan_context->SupportsBoundingBox())
  {
    BoundingBox* bounding_box = Renderer::GetInstance()->GetBoundingBox();
    bool bounding_box_enabled = (::BoundingBox::active && g_ActiveConfig.bBBoxEnable);
    if (bounding_box_enabled)
    {
      bounding_box->Flush();
      bounding_box->Invalidate();
    }
  }

  // Bind all pending state to the command buffer
  if (StateTracker::GetInstance()->Bind())
  {
    vkCmdDrawIndexed(g_command_buffer_mgr->GetCurrentCommandBuffer(), num_indices, 1, base_index,
                     base_vertex, 0);
  }
  else
  {
    WARN_LOG(VIDEO, "Skipped draw of %u indices", num_indices);
  }

  StateTracker::GetInstance()->OnDraw();
}

}  // namespace Vulkan