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#include "session/ime_switch_util.h"

#include <set>
#include <sstream>
#include <string>
#include <vector>

#include "base/base.h"
#include "base/config_file_stream.h"
#include "base/logging.h"
#include "base/singleton.h"
#include "base/util.h"
#include "config/config.pb.h"
#include "config/config_handler.h"
#include "session/commands.pb.h"
#include "session/internal/keymap.h"
#include "session/key_event_util.h"
#include "session/key_parser.h"

namespace mozc {
namespace config {
namespace {
const char kModeDirect[] = "Direct";
const char kModeDirectInput[] = "DirectInput";

class ImeSwitchUtilImpl {
 public:
  ImeSwitchUtilImpl() {
    Reload();
  }

  virtual ~ImeSwitchUtilImpl() {}

  bool IsDirectModeCommand(const commands::KeyEvent &key_event) const {
    KeyInformation key;
    if (!KeyEventUtil::GetKeyInformation(key_event, &key)) {
      return false;
    }
    for (size_t i = 0; i < keyevents_.size(); ++i) {
      KeyInformation ime_on_key;
      if (!KeyEventUtil::GetKeyInformation(keyevents_[i], &ime_on_key)) {
        continue;
      }
      if (key == ime_on_key) {
        return true;
      }
    }
    return false;
  }

  void Reload() {
    keyevents_.clear();
    const config::Config::SessionKeymap keymap = GET_CONFIG(session_keymap);
    if (keymap == Config::CUSTOM) {
      const string &custom_keymap_table = GET_CONFIG(custom_keymap_table);
      if (custom_keymap_table.empty()) {
        LOG(WARNING) << "custom_keymap_table is empty. use default setting";
        const char *default_keymapfile =
            keymap::KeyMapManager::GetKeyMapFileName(
                keymap::KeyMapManager::GetDefaultKeyMap());
        ReloadFromFile(default_keymapfile);
        return;
      }
      istringstream ifs(custom_keymap_table);
      ReloadFromStream(&ifs);
      return;
    }
    const char *keymap_file = keymap::KeyMapManager::GetKeyMapFileName(keymap);
    ReloadFromFile(keymap_file);
  }

  void GetTurnOnInDirectModeKeyEventList(
      vector<commands::KeyEvent> *key_events) const {
    *key_events = keyevents_;
  }

 private:
  void ReloadFromStream(istream *ifs) {
    string line;
    getline(*ifs, line);  // Skip the first line.
    while (!ifs->eof()) {
      getline(*ifs, line);
      Util::ChopReturns(&line);
      if (line.empty() || line[0] == '#') {
        // empty or comment
        continue;
      }
      vector<string> rules;
      Util::SplitStringUsing(line, "\t", &rules);
      if (rules.size() != 3) {
        LOG(ERROR) << "Invalid format: " << line;
        continue;
      }
      if (!(rules[0] == kModeDirect || rules[0] == kModeDirectInput)) {
        continue;
      }
      commands::KeyEvent key_event;
      KeyParser::ParseKey(rules[1], &key_event);
      keyevents_.push_back(key_event);
    }
  }

  void ReloadFromFile(const string &filename) {
    scoped_ptr<istream> ifs(ConfigFileStream::LegacyOpen(filename));
    if (ifs.get() == NULL) {
      DLOG(FATAL) << "could not open file: " << filename;
      return;
    }
    return ReloadFromStream(ifs.get());
  }

  // original forms
  vector<commands::KeyEvent> keyevents_;
};

}  // namespace

bool ImeSwitchUtil::IsDirectModeCommand(const commands::KeyEvent &key) {
  return Singleton<ImeSwitchUtilImpl>::get()->IsDirectModeCommand(key);
}

void ImeSwitchUtil::Reload() {
  Singleton<ImeSwitchUtilImpl>::get()->Reload();
}
}  // namespace config
}  // namespace mozc