package org.kuali.student.common.ui.client.mvc.breadcrumb;
   
   import java.util.ArrayList;
   import java.util.List;
   
   import org.kuali.student.common.ui.client.mvc.Controller;
   import org.kuali.student.common.ui.client.mvc.history.HistoryManager;
   import org.kuali.student.common.ui.client.widgets.field.layout.element.SpanPanel;
   
  import com.google.gwt.user.client.ui.ComplexPanel;
  import com.google.gwt.user.client.ui.Composite;
  import com.google.gwt.user.client.ui.Hyperlink;
  import com.google.gwt.user.client.ui.InlineLabel;
  import com.google.gwt.user.client.ui.Panel;
  import com.google.gwt.user.client.ui.Widget;
  
  /**
   * Manages breadcrumbs for the application
   * 
   * @author Kuali Student Team
   *
   */
  public class BreadcrumbManager extends Composite{
  	
  	public static List<Hyperlink> links = new ArrayList<Hyperlink>();
  	
  	private static List<String> names = new ArrayList<String>();
  	
  	private static Controller root;
  	private static ComplexPanel panel = new SpanPanel();
  	private static boolean panelEmpty = true;
  	
  	private static Panel parentPanel;
  	
  	private static class BreadcrumbData{
  		private String name;
  		private String path;
  		public BreadcrumbData(String name, String path) {
  			super();
  			this.name = name;
  			this.path = path;
  		}
  	}
  	
  	/**
  	 * Binds the controller as the top level controller to call collectBreadcrumbNames on.
  	 * 
  	 * @param controller
  	 */
  	public static void bind(Controller controller){
  		root = controller;
  	}
  	
  	/**
  	 * Updates the breadcrumb panel with the current breadcrumb by walking the controller hierarchy by calling
  	 * collectBreadcrumbNames on the root controller bound to the BreadcrumbManager.
  	 * 
  	 * @param historyStack
  	 */
  	public static void updateLinks(String historyStack){
  	    if (root == null){
  	        return;
  	    }
  	    
  		links.clear();
  		panel.clear();
  		panelEmpty = true;
  		names.clear();
  		root.collectBreadcrumbNames(names);
  		
  		String[] arr = HistoryManager.splitHistoryStack(historyStack);
  		List<BreadcrumbData> breadcrumbs = new ArrayList<BreadcrumbData>();
  
  		if(arr.length == names.size()){
  			String path = "";
  			//account for applicationController - skip first item from both
  			for(int i = 1; i < names.size(); i++){
  				path = path + "/" + arr[i];
  				String name = names.get(i);
  				//Views with empty names do not appear on the breadcrumbs
  				if(name != null && !name.isEmpty()){
  					breadcrumbs.add(new BreadcrumbData(name, path));
  				}
  			}
  		}
  		//Special link, a controller is adding a breadcrumb outside the scope of the current controller
  		//in format name@path
  		else if(names.size() > arr.length){
  			String path = "";
  			int j = 1;
  			//account for applicationController - skip first item from both
  			for(int i = 1; i < names.size(); i++){
  				String name = names.get(i);
  				if(name.contains("@")){
  					String[] split = name.split("@");
  					name = split[0];
  					if(name != null && !name.isEmpty()){
  						//In the special case the path is the second part of the split
  						breadcrumbs.add(new BreadcrumbData(name, split[1]));
 					}
 				}
 				else{
 					if(j == arr.length){
 						break;
 					}
 					path = path + "/" + arr[j];
 					j++;
 					if(name != null && !name.isEmpty()){
 						breadcrumbs.add(new BreadcrumbData(name, path));
 					}
 				}
 			}
 		}
 		
 		if(parentPanel != null){
 			if(breadcrumbs.size() == 1){
 				panel.getParent().setVisible(false);
 			}
 			else{
 				panel.getParent().setVisible(true);
 
 			}
 		}
 		
 		for(int i = 0; i < breadcrumbs.size(); i++){
 			if(i < breadcrumbs.size() - 1){
 				createLink(breadcrumbs.get(i).name, breadcrumbs.get(i).path);
 			}
 			else{
 				createLabel(breadcrumbs.get(i).name);
 				//WindowTitleUtils.setSubtitle(breadcrumbs.get(i).name);
 			}
 		}
 	}
 	
 	private static void createLabel(String name){
 		addToPanel(new InlineLabel(name));
 	}
 	
 	private static void createLink(String name, final String viewPath){
 		Hyperlink link = new Hyperlink(name, viewPath);
 		links.add(link);
 		addToPanel(link);
 	}
 	
 	private static void addToPanel(Widget w){
 		if(panelEmpty){
 			panel.add(w);
 			panelEmpty = false;
 		}
 		else{
 			panel.add(new InlineLabel(" \u00BB "));
 			panel.add(w);
 		}
 	}
 	
 	/** 
 	 * @return the breadcrumb panel which contains the breadcrumb links dynamically updated by the 
 	 * BreadcrumbManager
 	 */
 	public static ComplexPanel getBreadcrumbPanel(){
 		return panel;
 	}
 	
 	public static void setParentPanel(Panel panel){
 		parentPanel = panel;
 		parentPanel.setVisible(false);
 	}
 
 }