/* Copyright 2019 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_TOOLS_EVALUATION_EVALUATION_STAGE_H_
#define TENSORFLOW_LITE_TOOLS_EVALUATION_EVALUATION_STAGE_H_

#include "tensorflow/lite/c/c_api_internal.h"
#include "tensorflow/lite/tools/evaluation/proto/evaluation_config.pb.h"

namespace tflite {
namespace evaluation {

// Superclass for a single stage of an EvaluationPipeline.
// Defines basic skeleton for sub-classes to implement.
//
// Ideally EvaluationStages should obtain access to initilizer/input objects via
// Get/Set methods on pointers, and not take ownership unless necessary.
class EvaluationStage {
 public:
  // Initializes an EvaluationStage, including verifying the
  // EvaluationStageConfig. Returns kTfLiteError if initialization failed,
  // kTfLiteOk otherwise.
  //
  // Sub-classes are responsible for ensuring required class members are defined
  // via Get/Set methods.
  virtual TfLiteStatus Init() = 0;

  // An individual run of the EvaluationStage. This is where the task to be
  // evaluated takes place. Returns kTfLiteError if there was a failure,
  // kTfLiteOk otherwise.
  //
  // Sub-classes are responsible for ensuring they have access to required
  // inputs via Get/Set methods.
  virtual TfLiteStatus Run() = 0;

  // Returns the latest metrics based on all Run() calls made so far.
  virtual EvaluationStageMetrics LatestMetrics() = 0;

  virtual ~EvaluationStage() = default;

 protected:
  // Constructs an EvaluationStage.
  // Each subclass constructor must invoke this constructor.
  explicit EvaluationStage(const EvaluationStageConfig& config)
      : config_(config) {}

  EvaluationStageConfig config_;
};

}  // namespace evaluation
}  // namespace tflite

#endif  // TENSORFLOW_LITE_TOOLS_EVALUATION_EVALUATION_STAGE_H_
