package org.kiwix.kiwixmobile;

import androidx.lifecycle.ViewModel;
import androidx.lifecycle.ViewModelProvider;
import java.util.Map;
import javax.inject.Inject;
import javax.inject.Provider;
import javax.inject.Singleton;

/*
 * Kiwix Android
 * Copyright (C) 2018  Kiwix <android.kiwix.org>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
@Singleton
public class KiwixViewModelFactory implements ViewModelProvider.Factory {
  private final Map<Class<? extends ViewModel>, Provider<ViewModel>> creators;

  @Inject
  public KiwixViewModelFactory(Map<Class<? extends ViewModel>, Provider<ViewModel>> creators) {
    this.creators = creators;
  }

  @SuppressWarnings("unchecked")
  @Override
  public <T extends ViewModel> T create(Class<T> modelClass) {
    Provider<? extends ViewModel> creator = creators.get(modelClass);
    if (creator == null) {
      for (Map.Entry<Class<? extends ViewModel>, Provider<ViewModel>> entry : creators.entrySet()) {
        if (modelClass.isAssignableFrom(entry.getKey())) {
          creator = entry.getValue();
          break;
        }
      }
    }
    if (creator == null) {
      throw new IllegalArgumentException("unknown model class " + modelClass);
    }
    try {
      return (T) creator.get();
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }
}
