/*
    * Copyright (C) 2013 AMIS research group, Faculty of Mathematics and Physics, Charles University in Prague, Czech Republic
    *
    * 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/>.
   */
  package cz.cuni.amis.pogamut.ut2004.agent.navigation.navmesh;
  
  import java.util.logging.Logger;
  
  import cz.cuni.amis.pogamut.base.communication.worldview.IWorldView;
  import cz.cuni.amis.pogamut.base.communication.worldview.object.IWorldObjectEvent;
  import cz.cuni.amis.pogamut.base.communication.worldview.object.IWorldObjectEventListener;
  import cz.cuni.amis.pogamut.base.communication.worldview.object.event.WorldObjectFirstEncounteredEvent;
  import cz.cuni.amis.pogamut.base.utils.logging.IAgentLogger;
  import cz.cuni.amis.pogamut.base.utils.logging.LogCategory;
  import cz.cuni.amis.pogamut.ut2004.agent.navigation.navmesh.drawing.IUT2004ServerProvider;
  import cz.cuni.amis.pogamut.ut2004.agent.navigation.navmesh.drawing.NavMeshDraw;
  import cz.cuni.amis.pogamut.ut2004.communication.messages.gbinfomessages.GameInfo;
  import cz.cuni.amis.utils.NullCheck;
  
  /**
   * Main class of Navigation Mesh module
   * 
   * @author Jakub Tomek
   * @author Jakub Gemrot aka Jimmy
   */
  public class NavMeshModule {
  	
  	private IWorldView worldView;	
  	private Logger log;
  	
  	private NavMeshDraw navMeshDraw;
  	
  	//
  	// STATE
  	//
  	
  	private boolean loaded = false;
  	private GameInfo loadedForMap = null;
  	
  	//
  	// NAVMESH DATA STRUCTURES
  	//
  	
      private NavMesh navMesh;
      
      //
      // LISTENER
      //
      
      private IWorldObjectEventListener<GameInfo, IWorldObjectEvent<GameInfo>> gameInfoListener = new IWorldObjectEventListener<GameInfo, IWorldObjectEvent<GameInfo>>() {
  		@Override
  		public void notify(IWorldObjectEvent<GameInfo> event) {
  			load(event.getObject());
  		}
  	};
  	
      public NavMeshModule(IUT2004ServerProvider serverProvider, IWorldView worldView, IAgentLogger logger) {
      	if (logger == null) {
      		log = new LogCategory("NavMesh");
      	} else {
      		log = logger.getCategory("NavMesh");
      	}
      	
      	this.worldView = worldView;
      	NullCheck.check(this.worldView, "worldView");
      	
      	navMesh = new NavMesh(worldView, log);
      	
      	worldView.addObjectListener(GameInfo.class, WorldObjectFirstEncounteredEvent.class, gameInfoListener);
      	
      	GameInfo info = worldView.getSingle(GameInfo.class);
      	if (info != null) {
      		load(info);
      	}
      	
      	navMeshDraw = new NavMeshDraw(navMesh, log, serverProvider);
      }
      
      private void clear() {
      	log.warning("NavMesh has been cleared...");
      	
      	navMesh.clear();
          
          loaded = false;
          loadedForMap = null;
      }
      	
     private void load(GameInfo info) {
     	if (info == null) {
     		log.severe("Could not load for 'null' GameInfo!");
     		return;
     	}
         if (loaded) {
         	if (loadedForMap == null) {
         		// WTF?
         		clear();
         	} else {
         		if (loadedForMap.getLevel().equals(info.getLevel())) {
         			// ALREADY INITIALIZED FOR THE SAME LEVEL
         			return;
         		}
         	}
         }
         
         if (navMesh.load(info)) {
         	loaded = true;
         	loadedForMap = info;
         } else {
         	loaded = false;
         	loadedForMap = null;
         }
 
 	}
         	
 	// ================
     // PUBLIC INTERFACE
     // ================
     
     /**
      * Tells whether NavMesh has been initialized and {@link #getNavMesh()} is usable. 
      * @return
      */
     public boolean isInitialized() {
     	return loaded;
     }
     
     /**
      * Always non-null, always returns {@link NavMesh}. However, you should check {@link #isInitialized()} whether the {@link NavMesh} is usable.
      * @return
      */
     public NavMesh getNavMesh() {
     	return navMesh;
     }
     
     public NavMeshDraw getNavMeshDraw() {
     	return navMeshDraw;
     }
     
 }