package com.onaro.sanscreen.client.view;

import java.util.Collection;
import java.util.HashSet;
import java.util.Set;

public class CompositeDirectorUtils {
	
	protected CompositeDirectorUtils() {
		//do nothing
	}
	
	/**
	 * TODO: optimize this method.
	 * 
	 * @return The view director, or <code>null</code>.
	 */
	public static ViewDirector getDescendentById(ICompositeDirector compositeDirector, String targetViewId) {
		
		if (compositeDirector == null) throw new IllegalArgumentException("compositeDirector"); //$NON-NLS-1$
		if (targetViewId == null) throw new IllegalArgumentException("targetViewId"); //$NON-NLS-1$
		
		Set<ViewDirector> descendents = getDescendents(compositeDirector);
		
		for (ViewDirector descendent : descendents) {
			String descendentId = descendent.getId();
			
			if (targetViewId.equals(descendentId)) return descendent;
		}
		
		return null;
	}
	
	/**
	 * TODO: optimize this method.
	 * 
	 * @return The view director, or <code>null</code>.
	 */
	public static ViewDirector getDescendentByName(ICompositeDirector compositeDirector, String targetViewName) {
		
		if (compositeDirector == null) throw new IllegalArgumentException("compositeDirector"); //$NON-NLS-1$
		if (targetViewName == null) throw new IllegalArgumentException("targetViewName"); //$NON-NLS-1$
		
		Set<ViewDirector> descendents = getDescendents(compositeDirector);
		
		for (ViewDirector descendent : descendents) {
			String descendentName = descendent.getName();
			
			if (targetViewName.equals(descendentName)) return descendent;
		}
		
		return null;
	}
	
	/**
	 * Get all the descendent view directors of a given composite director.
	 */
	public static Set<ViewDirector> getDescendents(ICompositeDirector compositeDirector) {
		
		if (compositeDirector == null) throw new IllegalArgumentException("compositeDirector"); //$NON-NLS-1$
		
		Set<ViewDirector> descendents = new HashSet<ViewDirector>();
		
		getDescendents(compositeDirector, descendents);
		
		return descendents;
	}
	
	/**
	 * Get all the descendent view directors (of a given class type) of a given composite director.
	 */
	public static <T extends ViewDirector> Set<T> getDescendentsOfType(ICompositeDirector compositeDirector, Class<T> viewDirectorClass) {
		
		if (compositeDirector == null) throw new IllegalArgumentException("compositeDirector"); //$NON-NLS-1$
		if (viewDirectorClass == null) throw new IllegalArgumentException("viewDirectorClass"); //$NON-NLS-1$
		
		Set<ViewDirector> descendents = getDescendents(compositeDirector);
		
		Set<T> descendentsOfType = new HashSet<T>();
		
		for (ViewDirector descendent : descendents) {
			if (viewDirectorClass.isInstance(descendent)) {
				descendentsOfType.add(viewDirectorClass.cast(descendent));
			}
		}
		
		return descendentsOfType;
	}
	
	/**
	 * Do a BFS finding all the descendent view directors of a given composite director.  
	 */
	public static void getDescendents(ICompositeDirector compositeDirector, Collection<ViewDirector> descendents) {
		if (compositeDirector == null) throw new IllegalArgumentException("compositeDirector"); //$NON-NLS-1$
		if (descendents == null) throw new IllegalArgumentException("descendents"); //$NON-NLS-1$
		
		Collection<ViewDirector> childViewDirectors = compositeDirector.getChildViewDirectors();
		
		for (ViewDirector childViewDirector : childViewDirectors) {
			boolean added = descendents.add(childViewDirector);
			
			if (added && childViewDirector instanceof ICompositeDirector) {
				
				ICompositeDirector subCompositeDirector = (ICompositeDirector) childViewDirector;
				
				getDescendents(subCompositeDirector, descendents);
			}
		}
	}
}