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#include "session/ime_switch_util.h"

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

#include "base/config_file_stream.h"
#include "base/singleton.h"
#include "base/util.h"
#include "session/commands.pb.h"
#include "session/config_handler.h"
#include "session/config.pb.h"
#include "session/key_event_normalizer.h"
#include "session/key_parser.h"

namespace mozc {
namespace config {
namespace {
// TODO(toshiyuki): remove dup codes here.
const char kMSIMEKeyMapFile[] = "system://ms-ime.tsv";
const char kATOKKeyMapFile[] = "system://atok.tsv";
const char kKotoeriKeyMapFile[] = "system://kotoeri.tsv";
#ifdef OS_WINDOWS
const char *kDefaultKeyMapFile = kMSIMEKeyMapFile;
#else  // Mac or Linux
const char *kDefaultKeyMapFile = kKotoeriKeyMapFile;
#endif

const char kModeDirect[] = "Direct";
const char kModeDirectInput[] = "DirectInput";
const char kCommandIMEOn[] = "IMEOn";
const char kCommandHiragana[] = "InputModeHiragana";
const char kCommandFullKatakana[] = "InputModeFullKatakana";
const char kCommandHalfKatakana[] = "InputModeHalfKatakana";
const char kCommandFullAlphanumeric[] = "InputModeFullAlphanumeric";
const char kCommandHalfAlphanumeric[] = "InputModeHalfAlphanumeric";

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

  virtual ~ImeSwitchUtilImpl() {}

  bool IsTurnOnInDirectMode(const commands::KeyEvent &key_event) const {
    uint64 key;
    if (!KeyEventNormalizer::ToUint64(key_event, &key)) {
      return false;
    }
    for (size_t i = 0; i < ime_on_keyevents_.size(); ++i) {
      uint64 ime_on_key;
      if (!KeyEventNormalizer::ToUint64(ime_on_keyevents_[i], &ime_on_key)) {
        continue;
      }
      if (key == ime_on_key) {
        return true;
      }
    }
    return false;
  }

  void Reload() {
    ime_on_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";
        ReloadFromFile(kDefaultKeyMapFile);
        return;
      }
      istringstream ifs(custom_keymap_table);
      ReloadFromStream(&ifs);
      CheckMigration();
      return;
    }
    const char *keymap_file = GetKeyMapFileName(keymap);
    ReloadFromFile(keymap_file);
  }

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

 private:
  void CheckMigration() {
    // migration code
    // Add hankaku to ime_on_keyevents_ if the settings seem to
    // be from previous version.
    // This code can deleted after IME ON/OFF feature migration.
    // TODO(toshiyuki): remove this after 0.11 Beta.
    const char kKeyOn[] = "On";
    const char kKeyEisu[] = "Eisu";
    const char kKeyHankaku[] = "Hankaku/Zenkaku";
    const char kKeyKanji[] = "Kanji";

    uint64 key_on = 0;
    uint64 key_eisu = 0;
    {
      commands::KeyEvent key_event;
      KeyParser::ParseKey(kKeyOn, &key_event);
      KeyEventNormalizer::ToUint64(key_event, &key_on);
    }
    {
      commands::KeyEvent key_event;
      KeyParser::ParseKey(kKeyEisu, &key_event);
      KeyEventNormalizer::ToUint64(key_event, &key_eisu);
    }
    bool should_be_migrated = true;
    for (size_t i = 0; i < ime_on_keyevents_.size(); ++i) {
      uint64 key = 0;
      KeyEventNormalizer::ToUint64(ime_on_keyevents_[i], &key);
      if (key != key_on && key != key_eisu) {
        should_be_migrated = false;
        break;
      }
    }
    if (should_be_migrated) {
      commands::KeyEvent key_hankaku;
      commands::KeyEvent key_kanji;
      KeyParser::ParseKey(kKeyHankaku, &key_hankaku);
      KeyParser::ParseKey(kKeyKanji, &key_kanji);
      ime_on_keyevents_.push_back(key_hankaku);
      ime_on_keyevents_.push_back(key_kanji);;
    }
  }

  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) &&
            (rules[2] == kCommandIMEOn ||
             rules[2] == kCommandHiragana ||
             rules[2] == kCommandFullKatakana ||
             rules[2] == kCommandHalfKatakana ||
             rules[2] == kCommandFullAlphanumeric ||
             rules[2] == kCommandHalfAlphanumeric))) {
        continue;
      }
      commands::KeyEvent key_event;
      KeyParser::ParseKey(rules[1], &key_event);
      ime_on_keyevents_.push_back(key_event);
    }
  }

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

  const char *GetKeyMapFileName(
      const config::Config::SessionKeymap keymap) const {
    switch (keymap) {
      case config::Config::NONE:
        return kDefaultKeyMapFile;
      case config::Config::ATOK:
        return kATOKKeyMapFile;
      case config::Config::MSIME:
        return kMSIMEKeyMapFile;
      case config::Config::KOTOERI:
        return kKotoeriKeyMapFile;
      case config::Config::CUSTOM:
        DCHECK(false) << "should not be occured";
        return kDefaultKeyMapFile;
      default:
        return kDefaultKeyMapFile;
    }
  }

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

}  // namespace

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

void ImeSwitchUtil::GetTurnOnInDirectModeKeyEventList(
    vector<commands::KeyEvent> *key_events) {
  Singleton<ImeSwitchUtilImpl>::get()->
      GetTurnOnInDirectModeKeyEventList(key_events);
}

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