#ifndef moses_TargetWordInsertionFeature_h
#define moses_TargetWordInsertionFeature_h

#include <string>
#include <boost/unordered_set.hpp>

#include "FeatureFunction.h"
#include "FactorCollection.h"
#include "AlignmentInfo.h"

namespace Moses
{

/** Sets the features for length of source phrase, target phrase, both.
 */
class TargetWordInsertionFeature : public StatelessFeatureFunction {
private:
  boost::unordered_set<std::string> m_vocab;
  FactorType m_factorType;
  bool m_unrestricted;

public:
	TargetWordInsertionFeature(FactorType factorType = 0):
     StatelessFeatureFunction("twi", ScoreProducer::unlimited),
     m_factorType(factorType),
     m_unrestricted(true)
  {
		std::cerr << "Initializing target word insertion feature.." << std::endl;
  }
      
  bool Load(const std::string &filePath);
  void Evaluate(  const PhraseBasedFeatureContext& context,
  								ScoreComponentCollection* accumulator) const;

  void EvaluateChart( const ChartBasedFeatureContext& context, 
                      ScoreComponentCollection* accumulator) const;

  void ComputeFeatures(const TargetPhrase& targetPhrase,
		           	   ScoreComponentCollection* accumulator,
		           	   const AlignmentInfo &alignmentInfo) const;

  // basic properties
	std::string GetScoreProducerWeightShortName(unsigned) const { return "twi"; }
	size_t GetNumInputScores() const { return 0; }
};

}

#endif // moses_TargetWordInsertionFeature_h