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// Transform key event accoding to config.
// This class is designed for using with Singleton class.

#ifndef MOZC_SESSION_KEY_EVENT_TRANSFORMER_H_
#define MOZC_SESSION_KEY_EVENT_TRANSFORMER_H_

#include <string>

#include "absl/container/flat_hash_map.h"
#include "protocol/commands.pb.h"
#include "protocol/config.pb.h"

namespace mozc {
namespace session {

class KeyEventTransformer final {
 public:
  using Table = absl::flat_hash_map<std::string, commands::KeyEvent>;

  KeyEventTransformer();

  KeyEventTransformer(const KeyEventTransformer&) = default;
  KeyEventTransformer& operator=(const KeyEventTransformer&) = default;

  ~KeyEventTransformer() = default;

  // Updates the transform table accoding to config.
  void ReloadConfig(const config::Config& config);

  // Transforms key event accoding to transform table.
  // We should update table using ReloadConfig() before calling a this function.
  bool TransformKeyEvent(commands::KeyEvent* key_event) const;

  const Table& table() const { return table_; }
  config::Config::NumpadCharacterForm numpad_character_form() const {
    return numpad_character_form_;
  }

 private:
  // Transform the key event base on the rule.  This function is used
  // for special treatment with numpad keys.
  bool TransformKeyEventForNumpad(commands::KeyEvent* key_event) const;

  // Transform symbols for Kana input.  Character transformation for
  // Romanji input is performed in preedit/table.cc
  bool TransformKeyEventForKana(commands::KeyEvent* key_event) const;

  Table table_;
  config::Config::NumpadCharacterForm numpad_character_form_;
};

}  // namespace session
}  // namespace mozc

#endif  // MOZC_SESSION_KEY_EVENT_TRANSFORMER_H_
