/* Copyright (c) 2001 - 2007 TOPP - www.openplans.org. All rights reserved.
 * This code is licensed under the GPL 2.0 license, available at the root
 * application directory.
 */
package org.geoserver.web.wicket.browser;

import java.io.File;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.extensions.ajax.markup.html.IndicatingAjaxFallbackLink;
import org.apache.wicket.markup.html.basic.Label;
import org.apache.wicket.markup.html.link.Link;
import org.apache.wicket.markup.html.list.ListItem;
import org.apache.wicket.markup.html.list.ListView;
import org.apache.wicket.markup.html.panel.Panel;
import org.apache.wicket.model.IModel;

/**
 * A panel showing the path between the root directory and the current directory as a set
 * of links separated by "/", much like breadcrumbs in a web site. 
 * @author Andrea Aime - OpenGeo
 *
 */
@SuppressWarnings("serial")
public abstract class FileBreadcrumbs extends Panel {
    IModel rootFile;

    public FileBreadcrumbs(String id, IModel rootFile, IModel currentFile) {
        super(id, currentFile);

        this.rootFile = rootFile;
        add(new ListView("path", new BreadcrumbModel(rootFile, currentFile)) {

            @Override
            protected void populateItem(ListItem item) {
                File file = (File) item.getModelObject();
                boolean last = item.getIndex() == getList().size() - 1;
                
                // the link to the current path item
                Label name = new Label("pathItem", file.getName() + "/");
                Link link = new IndicatingAjaxFallbackLink("pathItemLink", item
                        .getModel()) {

                    @Override
                    public void onClick(AjaxRequestTarget target) {
                        pathItemClicked((File) getModelObject(), target);
                    }

                };
                link.add(name);
                item.add(link);
                link.setEnabled(!last);
            }

        });
    }
    
    public void setRootFile(File root) {
        rootFile.setObject(root);
    }
    
    public void setSelection(File selection) {
    	setDefaultModelObject(selection);
    }

    protected abstract void pathItemClicked(File file,
            AjaxRequestTarget target);

    static class BreadcrumbModel implements IModel {
        IModel rootFileModel;

        IModel currentFileModel;

        public BreadcrumbModel(IModel rootFileModel, IModel currentFileModel) {
            this.rootFileModel = rootFileModel;
            this.currentFileModel = currentFileModel;
        }

        public Object getObject() {
            File root = (File) rootFileModel.getObject();
            File current = (File) currentFileModel.getObject();

            // get all directories between current and root
            List<File> files = new ArrayList<File>();
            while (current != null && !current.equals(root)) {
                files.add(current);
                current = current.getParentFile();
            }
            if(current != null && current.equals(root))
                files.add(root);
            // reverse the order, we want them ordered from root
            // to current
            Collections.reverse(files);

            return files;
        }

        public void setObject(Object object) {
            throw new UnsupportedOperationException("This model cannot be set!");
        }

        public void detach() {
            // nothing to do here
        }

    }

}