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#ifndef MOZC_CONVERTER_CANDIDATE_FILTER_H_
#define MOZC_CONVERTER_CANDIDATE_FILTER_H_

#include <set>
#include <string>
#include <vector>
#include "base/port.h"
#include "converter/segments.h"

namespace mozc {

struct Node;
class POSMatcher;
class SuggestionFilter;
class SuppressionDictionary;

namespace converter {

class CandidateFilter {
 public:
  CandidateFilter(const SuppressionDictionary *suppression_dictionary,
                  const POSMatcher *pos_matcher,
                  const SuggestionFilter *suggestion_filter);
  ~CandidateFilter();

  enum ResultType {
    GOOD_CANDIDATE,    // Can insert the candidate into the list
    BAD_CANDIDATE,     // Do not insert the candidate
    STOP_ENUMERATION,  // Do not insert and stop enumurations
  };

  // Checks if the candidate should be filtered out.
  ResultType FilterCandidate(const string &original_key,
                             const Segment::Candidate *candidate,
                             const vector<const Node *> &nodes,
                             Segments::RequestType request_type);

  // Resets the internal state.
  void Reset();

 private:
  ResultType FilterCandidateInternal(const string &original_key,
                                     const Segment::Candidate *candidate,
                                     const vector<const Node *> &nodes,
                                     Segments::RequestType request_type);

  const SuppressionDictionary *suppression_dictionary_;
  const POSMatcher *pos_matcher_;
  const SuggestionFilter *suggestion_filter_;

  set<string> seen_;
  const Segment::Candidate *top_candidate_;

  DISALLOW_COPY_AND_ASSIGN(CandidateFilter);
};

}  // namespace converter
}  // namespace mozc

#endif  // MOZC_CONVERTER_CANDIDATE_FILTER_H_