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#ifndef MOZC_DICTIONARY_DICTIONARY_IMPL_H_
#define MOZC_DICTIONARY_DICTIONARY_IMPL_H_

#include <memory>
#include <string>
#include <vector>

#include "absl/strings/string_view.h"
#include "dictionary/dictionary_interface.h"
#include "dictionary/pos_matcher.h"
#include "request/conversion_request.h"

namespace mozc {
namespace dictionary {

class DictionaryImpl : public DictionaryInterface {
 public:
  // Initializes a dictionary with given dictionaries and POS data.  The system
  // and value dictionaries are owned by this class but the user dictionary is
  // just a reference and to be deleted by the caller. Note that the user
  // dictionary is not a const reference because this class may reload the user
  // dictionary.
  // TODO(noriyukit): Currently DictionaryInterface::Reload() is not used and
  // thus user_dictionary can be const as well. We can make it const after
  // clarifying the ownership of the user dictionary and changing code so that
  // the owner reloads it.
  DictionaryImpl(std::unique_ptr<const DictionaryInterface> system_dictionary,
                 std::unique_ptr<const DictionaryInterface> value_dictionary,
                 const UserDictionaryInterface& user_dictionary,
                 const PosMatcher& pos_matcher);

  DictionaryImpl(const DictionaryImpl&) = delete;
  DictionaryImpl& operator=(const DictionaryImpl&) = delete;

  ~DictionaryImpl() override;

  bool HasKey(absl::string_view key) const override;
  bool HasValue(absl::string_view value) const override;
  void LookupPredictive(absl::string_view key,
                        const ConversionRequest& conversion_request,
                        Callback* callback) const override;
  void LookupPrefix(absl::string_view key,
                    const ConversionRequest& conversion_request,
                    Callback* callback) const override;

  void LookupExact(absl::string_view key,
                   const ConversionRequest& conversion_request,
                   Callback* callback) const override;

  void LookupReverse(absl::string_view str,
                     const ConversionRequest& conversion_request,
                     Callback* callback) const override;

  bool LookupComment(absl::string_view key, absl::string_view value,
                     const ConversionRequest& conversion_request,
                     std::string* comment) const override;
  void PopulateReverseLookupCache(absl::string_view str) const override;
  void ClearReverseLookupCache() const override;

 private:
  enum LookupType {
    PREDICTIVE,
    PREFIX,
    REVERSE,
    EXACT,
  };

  // Used to check POS IDs.
  const PosMatcher& pos_matcher_;

  // Main three dictionaries.
  std::unique_ptr<const DictionaryInterface> system_dictionary_;
  std::unique_ptr<const DictionaryInterface> value_dictionary_;
  const UserDictionaryInterface& user_dictionary_;

  // Convenient container to handle the above three dictionaries as one
  // composite dictionary.
  std::vector<const DictionaryInterface*> dics_;
};

}  // namespace dictionary
}  // namespace mozc

#endif  // MOZC_DICTIONARY_DICTIONARY_IMPL_H_
