package cz.cuni.amis.pogamut.base.utils.logging;
   
   import java.util.Arrays;
   import java.util.Collections;
   import java.util.Comparator;
   import java.util.Map;
   import java.util.logging.Level;
   
   /**
   * Class that wraps the map with log categories. It allows you
   * to simply create new categories or query it's mapping.
   * <p><p>
   * The only constructor LogCategories(Logger) is protected and is instantiated
   * during the construction of AgentLogger.
   *
   * @author Jimmy
   */
  public abstract class AbstractLogCategories implements ILogCategories {
  
  	private Map<String, LogCategory> immutableCategories = null;
  
  	private Comparator<String> stringComparator = new Comparator<String>() {
  
  		@Override
  		public int compare(String o1, String o2) {
  			if (o1 == null) {
  				if (o1 == o2) return 0;
  				return -1;
  			}
  			if (o2 == null) return 1;
  			return o1.compareTo(o2);
  		}
  
  	};
  
      /**
       * @return Muttable map with categories.
       */
      protected abstract Map<String, LogCategory> getCategoriesInternal();
  
  
  	/**
  	 * Whether some category with specified name exists.
  	 * @param name
  	 * @return
  	 */
      @Override
  	public boolean hasCategory(String name) {
  		return Arrays.binarySearch(getCategoryNamesSorted(), name, stringComparator) >= 0;
  	}
  
  	/**
  	 * Returns IMMUTABLE mapping of cathegories names to instances of those log categories.
  	 * <p><p>
  	 * You have to synchronize on it before iterating through it!
  	 * @return
  	 */
      @Override
  	public Map<String, LogCategory> getCategories() {
          if(immutableCategories == null) {
              immutableCategories = Collections.unmodifiableMap(getCategoriesInternal());
          }
          return immutableCategories;
  	}
  
      /**
       * Used by {@link AbstractAgentLogger} to slip itself into the map.
       * @param name
       * @param category
       */
      @Override
      public void addLogCategory(String name, LogCategory category) {
      	getCategoriesInternal().put(name, category);
      }
  
  	/**
  	 * Returns names of all existing log categories.
  	 * @return
  	 */
      @Override
  	public String[] getCategoryNames() {
  		return getCategoriesInternal().keySet().toArray(new String[0]);
  	}
  
  	/**
  	 * Returns names of all existing log categories sorted alphabetically.
  	 * @return
  	 */
      @Override
  	public String[] getCategoryNamesSorted() {
  		String[] names = getCategoryNames();
  		Arrays.sort(names, stringComparator);
  		return names;
  	}
  
  	
  	/**
  	 * Set level for all handlers of all categories.
  	 *
 	 * @param newLevel
 	 */
     @Override
 	public void setLevel(Level newLevel) {
     	synchronized(getCategories()) {
     		for (LogCategory category : getCategories().values()) {
     			category.setLevel(newLevel);    		
     		}
     	}
 	}
 
 }