/*   **********************************************************************  **
 **   Copyright notice                                                       **
 **                                                                          **
 **   (c) 2005-2006 RSSOwl Development Team                                  **
 **   http://www.rssowl.org/                                                 **
 **                                                                          **
 **   All rights reserved                                                    **
 **                                                                          **
 **   This program and the accompanying materials are made available under   **
 **   the terms of the Eclipse Public License v1.0 which accompanies this    **
 **   distribution, and is available at:                                     **
 **   http://www.rssowl.org/legal/epl-v10.html                               **
 **                                                                          **
 **   A copy is found in the file epl-v10.html and important notices to the  **
 **   license from the team is found in the textfile LICENSE.txt distributed **
 **   in this package.                                                       **
 **                                                                          **
 **   This copyright notice MUST APPEAR in all copies of the file!           **
 **                                                                          **
 **   Contributors:                                                          **
 **     RSSOwl Development Team - initial API and implementation             **
 **                                                                          **
 **  **********************************************************************  */

package org.rssowl.ui.internal;

import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.jobs.Job;
import org.rssowl.core.Owl;
import org.rssowl.core.persist.INews;
import org.rssowl.core.persist.ISearchMark;
import org.rssowl.core.persist.INews.State;
import org.rssowl.core.persist.dao.DynamicDAO;
import org.rssowl.core.persist.dao.ISearchMarkDAO;
import org.rssowl.core.persist.event.SearchMarkEvent;
import org.rssowl.core.persist.reference.NewsReference;
import org.rssowl.core.persist.service.IModelSearch;
import org.rssowl.core.persist.service.IndexListener;
import org.rssowl.core.util.ISearchHit;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;

/**
 * @author bpasero
 */
public class SavedSearchService {
  private static final int BATCH_INTERVAL = 500;
  private Job fBatchJob;
  private IndexListener fIndexListener;
  private AtomicBoolean fBatchInProcess = new AtomicBoolean(false);

  /**
   *
   */
  public SavedSearchService() {
    fBatchJob = createBatchJob();
    registerListeners();
    updateSavedSearches();
  }

  private Job createBatchJob() {
    return new Job("Batch Job") {
      @Override
      protected IStatus run(IProgressMonitor monitor) {
        updateSavedSearches();
        fBatchInProcess.set(false);
        return Status.OK_STATUS;
      }
    };
  }

  private void registerListeners() {
    fIndexListener = new IndexListener() {
      public void indexUpdated() {
        onIndexUpdated();
      }
    };

    Owl.getPersistenceService().getModelSearch().addIndexListener(fIndexListener);
  }

  private void unregisterListeners() {
    Owl.getPersistenceService().getModelSearch().removeIndexListener(fIndexListener);
  }

  private void onIndexUpdated() {

    /* Batch is in process - return */
    if (fBatchInProcess.get())
      return;

    /* Start a new Batch */
    fBatchInProcess.set(true);
    fBatchJob.schedule(BATCH_INTERVAL);
  }

  private void updateSavedSearches() {
    IModelSearch modelSearch = Owl.getPersistenceService().getModelSearch();
    Set<ISearchMark> searchMarks = Controller.getDefault().getCacheService().getSearchMarks();
    Set<SearchMarkEvent> events = new HashSet<SearchMarkEvent>(searchMarks.size());

    for (ISearchMark searchMark : searchMarks) {
      List<ISearchHit<NewsReference>> results = modelSearch.searchNews(searchMark.getSearchConditions(), searchMark.matchAllConditions());

      List<NewsReference> readNews = null;
      List<NewsReference> unreadNews = null;
      List<NewsReference> newNews = null;

      for (ISearchHit<NewsReference> searchHit : results) {
        INews.State state = (State) searchHit.getData(INews.STATE);

        if (state == INews.State.READ) {
          if (readNews == null)
            readNews = new ArrayList<NewsReference>(results.size() / 3);

          readNews.add(searchHit.getResult());
        }

        else if (state == INews.State.UNREAD || state == INews.State.UPDATED) {
          if (unreadNews == null)
            unreadNews = new ArrayList<NewsReference>(results.size() / 3);

          unreadNews.add(searchHit.getResult());
        }

        else if (state == INews.State.NEW) {
          if (newNews == null)
            newNews = new ArrayList<NewsReference>(results.size() / 3);

          newNews.add(searchHit.getResult());
        }
      }

      searchMark.setResult(readNews, INews.State.READ);
      searchMark.setResult(unreadNews, INews.State.UNREAD);
      searchMark.setResult(newNews, INews.State.NEW);

      events.add(new SearchMarkEvent(searchMark, null, true));
    }

    /* Notify Listeners (TODO Optimize if nothing changed!) */
    DynamicDAO.getDAO(ISearchMarkDAO.class).fireResultsChanged(events);
  }

  /**
   *
   */
  public void stopService() {
    unregisterListeners();
  }
}