/*
    * Copyright (C) 2003-2015 eXo Platform SAS.
    *
    * This is free software; you can redistribute it and/or modify it
    * under the terms of the GNU Lesser General Public License as
    * published by the Free Software Foundation; either version 3 of
    * the License, or (at your option) any later version.
    *
    * This software 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
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this software; if not, write to the Free
   * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
   * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
   */
  package org.exoplatform.base;
  
  import java.lang.ref.WeakReference;
  import java.util.ArrayList;
  import java.util.HashSet;
  
  import org.exoplatform.utils.Log;
  
  import android.support.v4.app.FragmentActivity;
  
  /**
   * Created by The eXo Platform SAS Author : MinhTDH MinhTDH@exoplatform.com Jul
   * 20, 2015
   */
  public abstract class BaseActivity extends FragmentActivity {
    /**
     * same purpose with ActivityLifecycleCallbacks in API 14, but only interested
     * in onPaused and onResume.
     * 
     * @author MinhTDH
     */
    public interface ActivityLifecycleCallbacks {
      void onResume(BaseActivity act);
  
      void onPause(BaseActivity act);
    }
  
    public static class BasicActivityLifecycleCallbacks implements ActivityLifecycleCallbacks {
  
      @Override
      public void onResume(BaseActivity act) {
  
      }
  
      @Override
      public void onPause(BaseActivity act) {
  
      }
  
    }
    
    private HashSet<WeakReference<BasicActivityLifecycleCallbacks>> mLifeCycleCallbackSet =
        new HashSet<WeakReference<BasicActivityLifecycleCallbacks>>();
  
    public void addLifeCycleObserverRef(BasicActivityLifecycleCallbacks cbRef) {
      mLifeCycleCallbackSet.add(new WeakReference<BaseActivity.BasicActivityLifecycleCallbacks>(cbRef));
    }
  
    public void removeLifeCycleObserver(BasicActivityLifecycleCallbacks removeCb) {
      synchronized (mLifeCycleCallbackSet) {
        ArrayList<WeakReference<BasicActivityLifecycleCallbacks>> removeList =
            new ArrayList<WeakReference<BasicActivityLifecycleCallbacks>>();
        for (WeakReference<BasicActivityLifecycleCallbacks> cbRef : mLifeCycleCallbackSet) {
          BasicActivityLifecycleCallbacks cb = cbRef == null ? null : cbRef.get();
          if (cb == removeCb) {
            removeList.add(cbRef);
          }
        }
        for (WeakReference<BasicActivityLifecycleCallbacks> cbRef : removeList) {
          mLifeCycleCallbackSet.remove(cbRef);
        }
      }
    }
  
    @Override
    protected void onResume() {
      super.onResume();
      for (WeakReference<BasicActivityLifecycleCallbacks> cbRef : mLifeCycleCallbackSet) {
        BasicActivityLifecycleCallbacks cb = cbRef == null ? null : cbRef.get();
        if (cb != null) {
          cb.onResume(this);
        }
      }
    }
  
    @Override
    protected void onPause() {
      for (WeakReference<BasicActivityLifecycleCallbacks> cbRef : mLifeCycleCallbackSet) {
        BasicActivityLifecycleCallbacks cb = cbRef == null ? null : cbRef.get();
        if (cb != null) {
          cb.onPause(this);
       }
     }
     // clear release reference
     removeLifeCycleObserver(null);
     if (Log.LOGD)
       Log.d(getClass().getSimpleName(), "onPause isFinishing=", isFinishing(), " ", this);
     super.onPause();
   }
 }