// Ceres Solver - A fast non-linear least squares minimizer

// Copyright 2015 Google Inc. All rights reserved.

// http://ceres-solver.org/

//

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// modification, are permitted provided that the following conditions are met:

//

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//   this list of conditions and the following disclaimer.

// * Redistributions in binary form must reproduce the above copyright notice,

//   this list of conditions and the following disclaimer in the documentation

//   and/or other materials provided with the distribution.

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//   used to endorse or promote products derived from this software without

//   specific prior written permission.

//

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// Author: sameeragarwal@google.com (Sameer Agarwal)

#ifndef CERES_INTERNAL_GRADIENT_PROBLEM_EVALUATOR_H_

#define CERES_INTERNAL_GRADIENT_PROBLEM_EVALUATOR_H_

#include <map>

#include <string>

#include "ceres/evaluator.h"

#include "ceres/execution_summary.h"

#include "ceres/gradient_problem.h"

#include "ceres/internal/port.h"

#include "ceres/wall_time.h"

namespace ceres {

namespace internal {

class GradientProblemEvaluator : public Evaluator {

 public:

  explicit GradientProblemEvaluator(const GradientProblem& problem)

      : problem_(problem) {}

  virtual ~GradientProblemEvaluator() {}

  virtual SparseMatrix* CreateJacobian() const { return NULL; }

  virtual bool Evaluate(const EvaluateOptions& evaluate_options,

                        const double* state,

                        double* cost,

                        double* residuals,

                        double* gradient,

                        SparseMatrix* jacobian) {

    CHECK(jacobian == NULL);

    ScopedExecutionTimer total_timer("Evaluator::Total", &execution_summary_);

    // The reason we use Residual and Jacobian here even when we are

    // only computing the cost and gradient has to do with the fact

    // that the line search minimizer code is used by both the

    // GradientProblemSolver and the main CeresSolver coder where the

    // Evaluator evaluates the Jacobian, and these magic strings need

    // to be consistent across the code base for the time accounting

    // to work.

    ScopedExecutionTimer call_type_timer(

        gradient == NULL ? "Evaluator::Residual" : "Evaluator::Jacobian",

        &execution_summary_);

    execution_summary_.IncrementCall(gradient == NULL ? "Evaluator::Residual"

                                                      : "Evaluator::Jacobian");

    return problem_.Evaluate(state, cost, gradient);

  }

  virtual bool Plus(const double* state,

                    const double* delta,

                    double* state_plus_delta) const {

    return problem_.Plus(state, delta, state_plus_delta);

  }

  virtual int NumParameters() const {

    return problem_.NumParameters();

  }

  virtual int NumEffectiveParameters()  const {

    return problem_.NumLocalParameters();

  }

  virtual int NumResiduals() const { return 1; }

  virtual std::map<std::string, int> CallStatistics() const {

    return execution_summary_.calls();

  }

  virtual std::map<std::string, double> TimeStatistics() const {

    return execution_summary_.times();

  }

 private:

  const GradientProblem& problem_;

  ::ceres::internal::ExecutionSummary execution_summary_;

};

}  // namespace internal

}  // namespace ceres

#endif  // CERES_INTERNAL_GRADIENT_PROBLEM_EVALUATOR_H_