/* Copyright (c) 2022 PaddlePaddle 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. */

#pragma once

#include <string>

namespace phi {

enum class AllocationType : int8_t {
  UNDEFINED = 0,
  CPU = 1,
  GPU = 2,
  GPUPINNED = 3,
  XPU = 4,
  NPU = 5,
  NPUPINNED = 6,
  IPU = 7,
  MLU = 8,
  CUSTOM = 9,
};

const char* AllocationTypeStr(AllocationType type);

size_t GetOrRegisterGlobalDeviceTypeId(const std::string& device_type);
std::string GetGlobalDeviceType(size_t device_type_id_);

/// \brief The place is used to specify where the data is stored.
class Place {
 public:
  Place() : device(0), alloc_type_(AllocationType::UNDEFINED) {}

  explicit Place(AllocationType type,
                 int8_t id,
                 const std::string& dev_type = "")
      : device(id),
        alloc_type_(type),
        device_type_id_(GetOrRegisterGlobalDeviceTypeId(dev_type)) {}

  explicit Place(AllocationType type, const std::string& dev_type = "")
      : device(0),
        alloc_type_(type),
        device_type_id_(GetOrRegisterGlobalDeviceTypeId(dev_type)) {}

  void Reset(AllocationType type,
             int8_t device_id = 0,
             const std::string& dev_type = "") noexcept {
    alloc_type_ = type;
    device = device_id;
    if (!dev_type.empty()) {
      device_type_id_ = GetOrRegisterGlobalDeviceTypeId(dev_type);
    }
  }

  AllocationType GetType() const { return alloc_type_; }

  int8_t GetDeviceId() const { return device; }

  std::string GetDeviceType() const {
    return GetGlobalDeviceType(device_type_id_);
  }

  std::string DebugString() const;

  struct Hash {
    // Note: Now the number of bits we need does not exceed 32 bits, so there is
    // no need to use 64 bits. If needed in the future, it can be expanded,
    // but now we don’t over-design.
    uint32_t operator()(const Place& place) const;
  };

  uint32_t HashValue() const { return Hash()(*this); }

  inline bool operator==(const Place& rhs) const {
    return HashValue() == rhs.HashValue();
  }
  inline bool operator!=(const Place& rhs) const {
    return HashValue() != rhs.HashValue();
  }
  inline bool operator<(const Place& rhs) const {
    return HashValue() < rhs.HashValue();
  }

 public:
  // TODO(wilber): Just because of backward compatibility, it needs to be
  // changed to private in the future.
  int8_t device{0};

 private:
  AllocationType alloc_type_{AllocationType::UNDEFINED};
  size_t device_type_id_;
};

class CPUPlace : public Place {
 public:
  CPUPlace() : Place(AllocationType::CPU) {}

  CPUPlace(const CPUPlace&) = default;
  CPUPlace(const Place& place) : Place(AllocationType::CPU) {}  // NOLINT
};

class GPUPlace : public Place {
 public:
  GPUPlace() : Place(AllocationType::GPU, 0) {}
  explicit GPUPlace(int device_id) : Place(AllocationType::GPU, device_id) {}

  GPUPlace(const GPUPlace&) = default;
  GPUPlace(const Place& place)  // NOLINT
      : Place(AllocationType::GPU, place.GetDeviceId()) {}
};

class GPUPinnedPlace : public Place {
 public:
  GPUPinnedPlace() : Place(AllocationType::GPUPINNED) {}

  GPUPinnedPlace(const GPUPinnedPlace&) = default;
  GPUPinnedPlace(const Place& place)  // NOLINT
      : Place(AllocationType::GPUPINNED) {}
};

class XPUPlace : public Place {
 public:
  XPUPlace() : Place(AllocationType::XPU, 0) {}
  explicit XPUPlace(int device_id) : Place(AllocationType::XPU, device_id) {}

  XPUPlace(const XPUPlace&) = default;
  XPUPlace(const Place& place)  // NOLINT
      : Place(AllocationType::XPU, place.GetDeviceId()) {}
};

class NPUPlace : public Place {
 public:
  NPUPlace() : Place(AllocationType::NPU, 0) {}
  explicit NPUPlace(int device_id) : Place(AllocationType::NPU, device_id) {}

  NPUPlace(const NPUPlace&) = default;
  NPUPlace(const Place& place)  // NOLINT
      : Place(AllocationType::NPU, place.GetDeviceId()) {}
};

class NPUPinnedPlace : public Place {
 public:
  NPUPinnedPlace() : Place(AllocationType::NPUPINNED) {}

  NPUPinnedPlace(const NPUPinnedPlace&) = default;
  NPUPinnedPlace(const Place& place)  // NOLINT
      : Place(AllocationType::NPUPINNED) {}
};

class IPUPlace : public Place {
 public:
  IPUPlace() : Place(AllocationType::IPU, 0) {}
  explicit IPUPlace(int device_id) : Place(AllocationType::IPU, device_id) {}

  IPUPlace(const IPUPlace&) = default;
  IPUPlace(const Place& place)  // NOLINT
      : Place(AllocationType::IPU, place.GetDeviceId()) {}
};

class MLUPlace : public Place {
 public:
  MLUPlace() : Place(AllocationType::MLU, 0) {}
  explicit MLUPlace(int device_id) : Place(AllocationType::MLU, device_id) {}

  MLUPlace(const MLUPlace&) = default;
  MLUPlace(const Place& place)  // NOLINT
      : Place(AllocationType::MLU, place.GetDeviceId()) {}
};

class CustomPlace : public Place {
 public:
  CustomPlace() : Place(AllocationType::CUSTOM, 0, "") {}
  explicit CustomPlace(const std::string dev_type)
      : Place(AllocationType::CUSTOM, 0, dev_type) {}
  CustomPlace(const std::string dev_type, int device_id)
      : Place(AllocationType::CUSTOM, device_id, dev_type) {}

  CustomPlace(const CustomPlace&) = default;
  CustomPlace(const Place& place) {  // NOLINT
    if (place.GetType() == AllocationType::CUSTOM) {
      this->Reset(
          AllocationType::CUSTOM, place.GetDeviceId(), place.GetDeviceType());
    }
  }
};

std::ostream& operator<<(std::ostream&, const Place&);

}  // namespace phi

namespace paddle {
namespace experimental {
using AllocationType = phi::AllocationType;
using Place = phi::Place;
}  // namespace experimental
}  // namespace paddle