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#ifndef MOZC_CONVERTER_CONVERTER_INTERFACE_H_
#define MOZC_CONVERTER_CONVERTER_INTERFACE_H_

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

namespace mozc {

namespace composer {
  class Composer;
}  // namespace composer

class ConverterInterface {
 public:
  // Start conversion with key.
  // key is a request writtein in Hiragana sequence
  virtual bool StartConversion(Segments *segments,
                               const string &key) const = 0;

  // Start conversion with composer.
  virtual bool StartConversionWithComposer(
      Segments *segments, const composer::Composer *composer) const = 0;

  // Start reverse conversion with key.
  virtual bool StartReverseConversion(Segments *segments,
                                      const string &key) const = 0;

  // Start prediction with key (request_type = PREDICTION)
  virtual bool StartPrediction(Segments *segments,
                               const string &key) const = 0;

  // Start suggestion with key (request_type = SUGGESTION)
  virtual bool StartSuggestion(Segments *segments,
                               const string &key) const = 0;

  // Finish conversion.
  // Segments are cleared. Context is not clreared
  virtual bool FinishConversion(Segments *segments) const = 0;

  // Clear segments and keep the context
  virtual bool CancelConversion(Segments *segments) const = 0;

  // Reset segments and context
  virtual bool ResetConversion(Segments *segments) const = 0;

  // Revert last Finish operation
  virtual bool RevertConversion(Segments *segments) const = 0;

  // Expand the bunsetsu-segment at "segment_index" by candidate_size
  // DEPRECATED: This method doesn't take any effect.
  // TODO(taku): remove this method.
  virtual bool GetCandidates(Segments *segments,
                             size_t segment_index,
                             size_t candidate_size) const {
    return true;
  }

  // Commit candidate
  virtual bool CommitSegmentValue(Segments *segments,
                                  size_t segment_index,
                                  int    candidate_index) const = 0;

  // Focus the candidate.
  // This method is mainly called when user puts SPACE key
  // and changes the focused candidate.
  // In this method, Converter will find bracketing matching.
  // e.g., when user selects "「",  corresponding closing bracket "」"
  // is chosen in the preedit.
  virtual bool FocusSegmentValue(Segments *segments,
                                 size_t segment_index,
                                 int candidate_index) const = 0;

  // Revert the operation of CommitSegment
  virtual bool FreeSegmentValue(Segments *segments,
                                size_t segment_index) const = 0;

  // Commit the first segment and move the candidate
  // into history segment temporally.
  // Session can use this method for PartialSubmit.
  virtual bool SubmitFirstSegment(Segments *segments,
                                  size_t candidate_index) const = 0;

  // Resize segment_index-th segment by offset_length.
  // offset_lenth can be negative.
  virtual bool ResizeSegment(Segments *segments,
                             size_t segment_index,
                             int offset_length) const = 0;

  // Resize [start_segment_index, start_segment_index + segment_size]
  // segments with the new size in new_size_array.
  // size of new_size_array is specified in 'array_size'
  virtual bool ResizeSegment(Segments *segments,
                             size_t start_segment_index,
                             size_t segments_size,
                             const uint8 *new_size_array,
                             size_t array_size) const = 0;

  // Sync mutable user data to local file system.
  virtual bool Sync() const = 0;

  // Reload mutable data from local file system.
  virtual bool Reload() const = 0;

  // TODO(taku): Remove below methods as they are too specific.

  // clear user history data
  virtual bool ClearUserHistory() const = 0;

  // clear user prediction data
  virtual bool ClearUserPrediction() const = 0;

  // clear unused user prediction data
  virtual bool ClearUnusedUserPrediction() const = 0;

 protected:
  virtual ~ConverterInterface() {}
  ConverterInterface() {}

 private:
  DISALLOW_COPY_AND_ASSIGN(ConverterInterface);
};

class ConverterFactory {
 public:
  // Create singleton Converter insntance.
  // If failed, return NULL
  // TODO(taku): move them to ConverterFactory
  static ConverterInterface *GetConverter();

  // Inject a dependency for unittesting
  static void SetConverter(ConverterInterface *converter);

 private:
  ConverterFactory() {}
  ~ConverterFactory() {}
};

// static converter utilities
class ConverterUtil {
 public:
  // Make a segment having one candidate. The value of candidate is the
  // same as the preedit.  This function can be used for error handling.
  // When the converter fails, we can call this function to make a
  // virtual segment.
  static void InitSegmentsFromString(const string &key,
                                     const string &preedit,
                                     Segments *segments);

  // Complete Left id/Right id if they are not defined.
  // Some users don't push conversion button but directly
  // input hiragana sequence only with composition mode. Converter
  // cannot know which POS ids should be used for these directly-
  // input strings. This function estimates IDs from value heuristically.
  static void CompletePOSIds(Segment::Candidate *candidate);

 private:
  ConverterUtil() {}
  ~ConverterUtil() {}
};
}  // namespace mozc
#endif  // MOZC_CONVERTER_CONVERTER_INTERFACE_H_