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

#pragma once

#include <array>
#include <cstddef>
#include <memory>

#include "Common/CommonTypes.h"
#include "Common/LinearDiskCache.h"
#include "VideoBackends/Vulkan/Constants.h"
#include "VideoBackends/Vulkan/ShaderCache.h"
#include "VideoCommon/GeometryShaderGen.h"
#include "VideoCommon/NativeVertexFormat.h"
#include "VideoCommon/PixelShaderGen.h"
#include "VideoCommon/RenderBase.h"
#include "VideoCommon/UberShaderPixel.h"
#include "VideoCommon/UberShaderVertex.h"
#include "VideoCommon/VertexShaderGen.h"

namespace Vulkan
{
class StreamBuffer;
class VertexFormat;

class StateTracker
{
public:
  StateTracker() = default;
  ~StateTracker() = default;

  static StateTracker* GetInstance();
  static bool CreateInstance();
  static void DestroyInstance();

  const RasterizationState& GetRasterizationState() const
  {
    return m_pipeline_state.rasterization_state;
  }
  const DepthState& GetDepthStencilState() const { return m_pipeline_state.depth_state; }
  const BlendingState& GetBlendState() const { return m_pipeline_state.blend_state; }
  void SetVertexBuffer(VkBuffer buffer, VkDeviceSize offset);
  void SetIndexBuffer(VkBuffer buffer, VkDeviceSize offset, VkIndexType type);

  void SetRenderPass(VkRenderPass load_render_pass, VkRenderPass clear_render_pass);
  void SetFramebuffer(VkFramebuffer framebuffer, const VkRect2D& render_area);
  void SetVertexFormat(const VertexFormat* vertex_format);

  void SetRasterizationState(const RasterizationState& state);
  void SetMultisamplingstate(const MultisamplingState& state);
  void SetDepthState(const DepthState& state);
  void SetBlendState(const BlendingState& state);

  bool CheckForShaderChanges();
  void ClearShaders();

  void UpdateVertexShaderConstants();
  void UpdateGeometryShaderConstants();
  void UpdatePixelShaderConstants();

  void SetTexture(size_t index, VkImageView view);
  void SetSampler(size_t index, VkSampler sampler);

  void SetBBoxEnable(bool enable);
  void SetBBoxBuffer(VkBuffer buffer, VkDeviceSize offset, VkDeviceSize range);

  void UnbindTexture(VkImageView view);

  // When executing a command buffer, we want to recreate the descriptor set, as it will
  // now be in a different pool for the new command buffer.
  void InvalidateDescriptorSets();

  // Same with the uniforms, as the current storage will belong to the previous command buffer.
  void InvalidateConstants();

  // Set dirty flags on everything to force re-bind at next draw time.
  void SetPendingRebind();

  // Ends a render pass if we're currently in one.
  // When Bind() is next called, the pass will be restarted.
  // Calling this function is allowed even if a pass has not begun.
  bool InRenderPass() const { return m_current_render_pass != VK_NULL_HANDLE; }
  void BeginRenderPass();
  void EndRenderPass();

  // Ends the current render pass if it was a clear render pass.
  void BeginClearRenderPass(const VkRect2D& area, const VkClearValue clear_values[2]);
  void EndClearRenderPass();

  void SetViewport(const VkViewport& viewport);
  void SetScissor(const VkRect2D& scissor);

  bool Bind(bool rebind_all = false);

  // CPU Access Tracking
  // Call after a draw call is made.
  void OnDraw();

  // Call after CPU access is requested.
  // This can be via EFBCache or EFB2RAM.
  void OnReadback();

  // Call at the end of a frame.
  void OnEndFrame();

  // Prevent/allow background command buffer execution.
  // Use when queries are active.
  void SetBackgroundCommandBufferExecution(bool enabled);

  bool IsWithinRenderArea(s32 x, s32 y, u32 width, u32 height) const;

  // Reloads the UID cache, ensuring all pipelines used by the game so far have been created.
  void ReloadPipelineUIDCache();

  // Clears shader pointers, ensuring that now-deleted modules are not used.
  void InvalidateShaderPointers();

private:
  // Serialized version of PipelineInfo, used when loading/saving the pipeline UID cache.
  struct SerializedPipelineUID
  {
    u32 rasterizer_state_bits;
    u32 depth_state_bits;
    u32 blend_state_bits;
    PortableVertexDeclaration vertex_decl;
    VertexShaderUid vs_uid;
    GeometryShaderUid gs_uid;
    PixelShaderUid ps_uid;
  };

  // Number of descriptor sets for game draws.
  enum
  {
    NUM_GX_DRAW_DESCRIPTOR_SETS = DESCRIPTOR_SET_BIND_POINT_PIXEL_SHADER_SAMPLERS + 1,
    NUM_GX_DRAW_WITH_BBOX_DESCRIPTOR_SETS = DESCRIPTOR_SET_BIND_POINT_STORAGE_OR_TEXEL_BUFFER + 1
  };

  enum DITRY_FLAG : u32
  {
    DIRTY_FLAG_VS_UBO = (1 << 0),
    DIRTY_FLAG_GS_UBO = (1 << 1),
    DIRTY_FLAG_PS_UBO = (1 << 2),
    DIRTY_FLAG_PS_SAMPLERS = (1 << 3),
    DIRTY_FLAG_PS_SSBO = (1 << 4),
    DIRTY_FLAG_DYNAMIC_OFFSETS = (1 << 5),
    DIRTY_FLAG_VERTEX_BUFFER = (1 << 6),
    DIRTY_FLAG_INDEX_BUFFER = (1 << 7),
    DIRTY_FLAG_VIEWPORT = (1 << 8),
    DIRTY_FLAG_SCISSOR = (1 << 9),
    DIRTY_FLAG_PIPELINE = (1 << 10),
    DIRTY_FLAG_DESCRIPTOR_SET_BINDING = (1 << 11),
    DIRTY_FLAG_PIPELINE_BINDING = (1 << 12),

    DIRTY_FLAG_ALL_DESCRIPTOR_SETS = DIRTY_FLAG_VS_UBO | DIRTY_FLAG_GS_UBO | DIRTY_FLAG_PS_UBO |
                                     DIRTY_FLAG_PS_SAMPLERS | DIRTY_FLAG_PS_SSBO
  };

  bool Initialize();

  // Appends the specified pipeline info, combined with the UIDs stored in the class.
  // The info is here so that we can store variations of a UID, e.g. blend state.
  void AppendToPipelineUIDCache(const PipelineInfo& info);

  // Precaches a pipeline based on the UID information.
  bool PrecachePipelineUID(const SerializedPipelineUID& uid);

  // Check that the specified viewport is within the render area.
  // If not, ends the render pass if it is a clear render pass.
  bool IsViewportWithinRenderArea() const;

  // Obtains a Vulkan pipeline object for the specified pipeline configuration.
  // Also adds this pipeline configuration to the UID cache if it is not present already.
  VkPipeline GetPipelineAndCacheUID();

  // Are bounding box ubershaders enabled? If so, we need to ensure the SSBO is set up,
  // since the bbox writes are determined by a uniform.
  bool IsSSBODescriptorRequired() const;

  bool UpdatePipeline();
  void UpdatePipelineLayout();
  void UpdatePipelineVertexFormat();
  bool UpdateDescriptorSet();

  // Allocates storage in the uniform buffer of the specified size. If this storage cannot be
  // allocated immediately, the current command buffer will be submitted and all stage's
  // constants will be re-uploaded. false will be returned in this case, otherwise true.
  bool ReserveConstantStorage();
  void UploadAllConstants();

  // Which bindings/state has to be updated before the next draw.
  u32 m_dirty_flags = 0;

  // input assembly
  VkBuffer m_vertex_buffer = VK_NULL_HANDLE;
  VkDeviceSize m_vertex_buffer_offset = 0;
  VkBuffer m_index_buffer = VK_NULL_HANDLE;
  VkDeviceSize m_index_buffer_offset = 0;
  VkIndexType m_index_type = VK_INDEX_TYPE_UINT16;

  // shader state
  VertexShaderUid m_vs_uid = {};
  GeometryShaderUid m_gs_uid = {};
  PixelShaderUid m_ps_uid = {};
  UberShader::VertexShaderUid m_uber_vs_uid = {};
  UberShader::PixelShaderUid m_uber_ps_uid = {};
  bool m_using_ubershaders = false;

  // pipeline state
  PipelineInfo m_pipeline_state = {};
  VkPipeline m_pipeline_object = VK_NULL_HANDLE;
  const VertexFormat* m_vertex_format = nullptr;

  // shader bindings
  std::array<VkDescriptorSet, NUM_DESCRIPTOR_SET_BIND_POINTS> m_descriptor_sets = {};
  struct
  {
    std::array<VkDescriptorBufferInfo, NUM_UBO_DESCRIPTOR_SET_BINDINGS> uniform_buffer_bindings =
        {};
    std::array<uint32_t, NUM_UBO_DESCRIPTOR_SET_BINDINGS> uniform_buffer_offsets = {};

    std::array<VkDescriptorImageInfo, NUM_PIXEL_SHADER_SAMPLERS> ps_samplers = {};

    VkDescriptorBufferInfo ps_ssbo = {};
  } m_bindings;
  u32 m_num_active_descriptor_sets = 0;
  size_t m_uniform_buffer_reserve_size = 0;

  // rasterization
  VkViewport m_viewport = {0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f};
  VkRect2D m_scissor = {{0, 0}, {1, 1}};

  // uniform buffers
  std::unique_ptr<StreamBuffer> m_uniform_stream_buffer;

  VkFramebuffer m_framebuffer = VK_NULL_HANDLE;
  VkRenderPass m_load_render_pass = VK_NULL_HANDLE;
  VkRenderPass m_clear_render_pass = VK_NULL_HANDLE;
  VkRenderPass m_current_render_pass = VK_NULL_HANDLE;
  VkRect2D m_framebuffer_size = {};
  VkRect2D m_framebuffer_render_area = {};
  bool m_bbox_enabled = false;

  // CPU access tracking
  u32 m_draw_counter = 0;
  std::vector<u32> m_cpu_accesses_this_frame;
  std::vector<u32> m_scheduled_command_buffer_kicks;
  bool m_allow_background_execution = true;

  // Draw state cache on disk
  // We don't actually use the value field here, instead we generate the shaders from the uid
  // on-demand. If all goes well, it should hit the shader and Vulkan pipeline cache, therefore
  // loading should be reasonably efficient.
  LinearDiskCache<SerializedPipelineUID, u32> m_uid_cache;
};
}