/* Copyright 2020 The TensorFlow Authors. All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
==============================================================================*/

#ifndef TENSORFLOW_LITE_DELEGATES_GPU_COMMON_TASK_GPU_OBJECT_DESC_H_
#define TENSORFLOW_LITE_DELEGATES_GPU_COMMON_TASK_GPU_OBJECT_DESC_H_

#include <map>
#include <memory>
#include <string>
#include <vector>

#include "tensorflow/lite/delegates/gpu/common/access_type.h"
#include "tensorflow/lite/delegates/gpu/common/data_type.h"
#include "tensorflow/lite/delegates/gpu/common/status.h"
#include "tensorflow/lite/delegates/gpu/common/task/serialization_base_generated.h"

namespace tflite {
namespace gpu {

struct GPUImage2DDescriptor {
  DataType data_type;
  AccessType access_type;
};

struct GPUImage3DDescriptor {
  DataType data_type;
  AccessType access_type;
};

struct GPUImage2DArrayDescriptor {
  DataType data_type;
  AccessType access_type;
};

struct GPUImageBufferDescriptor {
  DataType data_type;
  AccessType access_type;
};

struct GPUCustomMemoryDescriptor {
  std::string type_name;
};

enum class MemoryType { GLOBAL, CONSTANT, LOCAL };

struct GPUBufferDescriptor {
  DataType data_type;
  AccessType access_type;
  int element_size;
  MemoryType memory_type = MemoryType::GLOBAL;
  std::vector<std::string> attributes;
};

struct GPUResources {
  std::vector<std::string> ints;
  std::vector<std::string> floats;
  std::vector<std::pair<std::string, GPUBufferDescriptor>> buffers;
  std::vector<std::pair<std::string, GPUImage2DDescriptor>> images2d;
  std::vector<std::pair<std::string, GPUImage2DArrayDescriptor>> image2d_arrays;
  std::vector<std::pair<std::string, GPUImage3DDescriptor>> images3d;
  std::vector<std::pair<std::string, GPUImageBufferDescriptor>> image_buffers;
  std::vector<std::pair<std::string, GPUCustomMemoryDescriptor>>
      custom_memories;

  std::vector<std::string> GetNames() const {
    std::vector<std::string> names = ints;
    names.insert(names.end(), floats.begin(), floats.end());
    for (const auto& obj : buffers) {
      names.push_back(obj.first);
    }
    for (const auto& obj : images2d) {
      names.push_back(obj.first);
    }
    for (const auto& obj : image2d_arrays) {
      names.push_back(obj.first);
    }
    for (const auto& obj : images3d) {
      names.push_back(obj.first);
    }
    for (const auto& obj : image_buffers) {
      names.push_back(obj.first);
    }
    for (const auto& obj : custom_memories) {
      names.push_back(obj.first);
    }
    return names;
  }
};

class GPUObjectDescriptor {
 public:
  GPUObjectDescriptor() = default;
  GPUObjectDescriptor(const GPUObjectDescriptor&) = default;
  GPUObjectDescriptor& operator=(const GPUObjectDescriptor&) = default;
  GPUObjectDescriptor(GPUObjectDescriptor&& obj_desc) = default;
  GPUObjectDescriptor& operator=(GPUObjectDescriptor&& obj_desc) = default;
  virtual ~GPUObjectDescriptor() = default;

  void SetStateVar(const std::string& key, const std::string& value) const {
    state_vars_[key] = value;
  }

  virtual std::string PerformConstExpr(const std::string& const_expr) const {
    return "";
  }

  virtual absl::Status PerformSelector(
      const std::string& selector, const std::vector<std::string>& args,
      const std::vector<std::string>& template_args,
      std::string* result) const {
    *result = "";
    return absl::OkStatus();
  }
  virtual GPUResources GetGPUResources() const { return GPUResources(); }

  virtual void Release() {}

  void SetAccess(AccessType access_type) { access_type_ = access_type; }
  AccessType GetAccess() const { return access_type_; }

 protected:
  friend flatbuffers::Offset<tflite::gpu::data::GPUObjectDescriptor> Encode(
      const GPUObjectDescriptor& desc, flatbuffers::FlatBufferBuilder* builder);
  friend void Decode(const tflite::gpu::data::GPUObjectDescriptor* fb_obj,
                     GPUObjectDescriptor* obj);
  mutable std::map<std::string, std::string> state_vars_;
  AccessType access_type_;
};

using GPUObjectDescriptorPtr = std::unique_ptr<GPUObjectDescriptor>;

}  // namespace gpu
}  // namespace tflite

#endif  // TENSORFLOW_LITE_DELEGATES_GPU_COMMON_TASK_GPU_OBJECT_DESC_H_
