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#ifndef MOZC_PREDICTION_PREDICTOR_H_
#define MOZC_PREDICTION_PREDICTOR_H_

#include <string>

#include "base/scoped_ptr.h"
#include "converter/conversion_request.h"
#include "prediction/predictor_interface.h"

namespace mozc {

class BasePredictor : public PredictorInterface {
 public:
  // Initializes the composite of predictor with given sub-predictors. All the
  // predictors are owned by this class and deleted on destruction of this
  // instance.
  BasePredictor(PredictorInterface *dictionary_predictor,
                PredictorInterface *user_history_predictor);
  virtual ~BasePredictor();

  // Overwrite predictor
  virtual bool PredictForRequest(const ConversionRequest &request,
                                 Segments *segments) const = 0;

  // Hook(s) for all mutable operations.
  virtual void Finish(Segments *segments);

  // Reverts the last Finish operation.
  virtual void Revert(Segments *segments);

  // Clears all history data of UserHistoryPredictor.
  virtual bool ClearAllHistory();

  // Clears unused history data of UserHistoryPredictor.
  virtual bool ClearUnusedHistory();

  // Clears a specific user history data of UserHistoryPredictor.
  virtual bool ClearHistoryEntry(const string &key, const string &value);

  // Syncs user history.
  virtual bool Sync();

  // Reloads usre history.
  virtual bool Reload();

  // Waits for syncer to complete.
  virtual bool WaitForSyncerForTest();

  virtual const string &GetPredictorName() const = 0;

 protected:
  scoped_ptr<PredictorInterface> dictionary_predictor_;
  scoped_ptr<PredictorInterface> user_history_predictor_;
};

// TODO(team): The name should be DesktopPredictor
class DefaultPredictor : public BasePredictor {
 public:
  static PredictorInterface *CreateDefaultPredictor(
      PredictorInterface *dictionary_predictor,
      PredictorInterface *user_history_predictor);

  DefaultPredictor(PredictorInterface *dictionary_predictor,
                   PredictorInterface *user_history_predictor);
  virtual ~DefaultPredictor();

  virtual bool PredictForRequest(const ConversionRequest &request,
                                 Segments *segments) const;

  virtual const string &GetPredictorName() const { return predictor_name_; }

 private:
  const ConversionRequest empty_request_;
  const string predictor_name_;
};

class MobilePredictor : public BasePredictor {
 public:
  static PredictorInterface *CreateMobilePredictor(
      PredictorInterface *dictionary_predictor,
      PredictorInterface *user_history_predictor);

  MobilePredictor(PredictorInterface *dictionary_predictor,
                  PredictorInterface *user_history_predictor);
  virtual ~MobilePredictor();

  virtual bool PredictForRequest(const ConversionRequest &request,
                                 Segments *segments) const;

  virtual const string &GetPredictorName() const { return predictor_name_; }

 private:
  const ConversionRequest empty_request_;
  const string predictor_name_;
};

}  // namespace mozc

#endif  // MOZC_PREDICTION_PREDICTOR_H_