/*=========================================================================
 *
 *  Copyright Insight Software Consortium
 *
 *  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.txt
 *
 *  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 itkFastMarchingReachedTargetNodesStoppingCriterion_h
#define itkFastMarchingReachedTargetNodesStoppingCriterion_h

#include "itkFastMarchingStoppingCriterionBase.h"
#include "itkObjectFactory.h"

namespace itk
{
/**
 * \class FastMarchingReachedTargetNodesStoppingCriterion
 * \brief Stopping criterion for FastMarchingFilterBase.
 *
 * Stopping criterion where the condition is satisfied when the front
 * reaches one, several or all target nodes (provided by the user).
 *
 * \ingroup ITKFastMarching
 */
template< typename TInput, typename TOutput >
class FastMarchingReachedTargetNodesStoppingCriterion :
public FastMarchingStoppingCriterionBase< TInput, TOutput >
{
public:
  ITK_DISALLOW_COPY_AND_ASSIGN(FastMarchingReachedTargetNodesStoppingCriterion);

  using Self = FastMarchingReachedTargetNodesStoppingCriterion;
  using Superclass = FastMarchingStoppingCriterionBase< TInput, TOutput >;
  using Pointer = SmartPointer< Self >;
  using ConstPointer = SmartPointer< const Self >;
  using Traits = typename Superclass::Traits;

  /** Method for creation through the object factory. */
  itkNewMacro(Self);

  /** Run-time type information (and related methods). */
  itkTypeMacro(FastMarchingReachedTargetNodesStoppingCriterion,
                FastMarchingStoppingCriterionBase );

  using OutputPixelType = typename Superclass::OutputPixelType;
  using NodeType = typename Superclass::NodeType;

  /** \enum TargetConditionType */
  enum TargetConditionType { OneTarget = 1,
                              SomeTargets,
                              AllTargets };

  /** Set/Get TargetCondition to indicate if the user wants the front to
  reach one, some or all target nodes. */
  void SetTargetCondition( const TargetConditionType& iCondition )
  {
    m_TargetCondition = iCondition;
    m_Initialized = false;
    this->Modified();
  }

  itkGetConstReferenceMacro( TargetCondition, TargetConditionType );

  /** Set/Get TargetOffset */
  itkSetMacro( TargetOffset, OutputPixelType );
  itkGetMacro( TargetOffset, OutputPixelType );

  /** \brief Set the number of target nodes to be reached */
  void SetNumberOfTargetsToBeReached( const size_t& iN )
  {
    m_NumberOfTargetsToBeReached = iN;
    m_Initialized = false;
    this->Modified();
  }

  /** \brief Set Target Nodes*/
  virtual void SetTargetNodes( const std::vector< NodeType >& iNodes )
  {
    m_TargetNodes = iNodes;
    m_Initialized = false;
    this->Modified();
  }

  /** \brief Set the current node */
  void SetCurrentNode( const NodeType& iNode ) override
  {
    if( !m_Initialized )
      {
      Initialize();
      }

    if( !m_Satisfied )
      {
      // Only check for reached targets if the mode is not NoTargets and
      // there is at least one TargetPoint.
      if ( !m_TargetNodes.empty() )
        {
        typename std::vector< NodeType >::const_iterator
            pointsIter = m_TargetNodes.begin();
        typename std::vector< NodeType >::const_iterator
            pointsEnd = m_TargetNodes.end();

        while( pointsIter != pointsEnd )
          {
          if ( *pointsIter == iNode )
            {
            this->m_ReachedTargetNodes.push_back( iNode );
            m_Satisfied =
                ( m_ReachedTargetNodes.size() == m_NumberOfTargetsToBeReached );
            break;
            }
          ++pointsIter;
          }
        if( m_Satisfied )
          {
          m_StoppingValue = this->m_CurrentValue + m_TargetOffset;
          }
        }
      else
        {
        m_Satisfied = false;
        }
      }
  }

  /** \brief returns if the stopping condition is satisfied or not. */
  bool IsSatisfied() const override
  {
    return m_Satisfied && ( this->m_CurrentValue >= m_StoppingValue );
  }

  /** \brief Get a short description of the stopping criterion. */
  std::string GetDescription() const override
  {
    return "Target Nodes Reached with possible overshoot";
  }

protected:

  /** Constructor */
  FastMarchingReachedTargetNodesStoppingCriterion() :
    Superclass(),
    m_TargetCondition(AllTargets),
    m_TargetOffset(NumericTraits< OutputPixelType >::ZeroValue()),
    m_StoppingValue(NumericTraits< OutputPixelType >::ZeroValue())

  {
  }

  /** Destructor */
  ~FastMarchingReachedTargetNodesStoppingCriterion() override = default;

  TargetConditionType     m_TargetCondition;
  std::vector< NodeType > m_TargetNodes;
  std::vector< NodeType > m_ReachedTargetNodes;
  size_t                  m_NumberOfTargetsToBeReached{0};
  OutputPixelType         m_TargetOffset;
  OutputPixelType         m_StoppingValue;
  bool                    m_Satisfied{false};
  bool                    m_Initialized{false};

  void Reset() override
  {
    this->Initialize();
  }

  void Initialize()
  {
    if( m_TargetCondition == OneTarget )
      {
      m_NumberOfTargetsToBeReached = 1;
      }
    if( m_TargetCondition == AllTargets )
      {
      m_NumberOfTargetsToBeReached = m_TargetNodes.size();
      }
    if( m_NumberOfTargetsToBeReached < 1 )
      {
      itkExceptionMacro(
            <<"Number of target nodes to be reached is null" );
      }
    if( m_NumberOfTargetsToBeReached > m_TargetNodes.size() )
      {
      itkExceptionMacro(
        <<"Number of target nodes to be reached is above the provided number of           target nodes" );
      }
    m_ReachedTargetNodes.clear();

    m_Satisfied = false;
    m_Initialized = true;
  }
};
}
#endif // itkFastMarchingThresholdStoppingCriterion_h
