package org.drools.process.instance.impl.demo;



import java.awt.BorderLayout;

import java.awt.Dimension;

import java.awt.GridBagConstraints;

import java.awt.GridBagLayout;

import java.awt.Insets;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.Iterator;

import java.util.List;

import java.util.Map;



import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JList;

import javax.swing.JPanel;

import javax.swing.ListSelectionModel;

import javax.swing.WindowConstants;

import javax.swing.event.ListSelectionEvent;

import javax.swing.event.ListSelectionListener;



import org.drools.runtime.process.WorkItem;

import org.drools.runtime.process.WorkItemHandler;

import org.drools.runtime.process.WorkItemManager;



/**

 * 

 * @author <a href="mailto:kris_verlaenen@hotmail.com">Kris Verlaenen</a>

 */

public class UIWorkItemHandler extends JFrame implements WorkItemHandler {



    private static final long serialVersionUID = 400L;

    

    private Map<WorkItem, WorkItemManager> workItems = new HashMap<WorkItem, WorkItemManager>();

    private JList workItemsList;

    private JButton selectButton;

    

    public UIWorkItemHandler() {

        setSize(new Dimension(400, 300));

        setTitle("Work Items");

        setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);

        initializeComponent();

    }

    

    private void initializeComponent() {

        JPanel panel = new JPanel();

        panel.setLayout(new GridBagLayout());

        getRootPane().setLayout(new BorderLayout());

        getRootPane().add(panel, BorderLayout.CENTER);

        

        workItemsList = new JList();

        workItemsList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);

        workItemsList.addMouseListener(new MouseAdapter() {

            public void mouseClicked(MouseEvent e) {

                if (e.getClickCount() == 2) {

                    select();

                }

            }

        });

        workItemsList.addListSelectionListener(new ListSelectionListener() {

            public void valueChanged(ListSelectionEvent e) {

                selectButton.setEnabled(getSelectedWorkItem() != null);

            }

        });

        reloadWorkItemsList();

        GridBagConstraints c = new GridBagConstraints();

        c.weightx = 1;

        c.weighty = 1;

        c.fill = GridBagConstraints.BOTH;

        c.insets = new Insets(5, 5, 5, 5);

        panel.add(workItemsList, c);

        

        selectButton = new JButton("Select");

        selectButton.setEnabled(false);

        selectButton.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent event) {

                select();

            }

        });

        c = new GridBagConstraints();

        c.gridy = 1;

        c.weightx = 1;

        c.anchor = GridBagConstraints.EAST;

        c.insets = new Insets(5, 5, 5, 5);

        panel.add(selectButton, c);

    }

    

    private void select() {

        WorkItem workItem = getSelectedWorkItem();

        if (workItem != null) {

            UIWorkItemHandlerDialog dialog = new UIWorkItemHandlerDialog(UIWorkItemHandler.this, workItem);

            dialog.setVisible(true);

        }

    }

    

    public WorkItem getSelectedWorkItem() {

        int index = workItemsList.getSelectedIndex();

        if (index != -1) {

            Object selected = workItemsList.getModel().getElementAt(index);

            if (selected instanceof WorkItemWrapper) {

                return ((WorkItemWrapper) selected).getWorkItem();

            }

        }

        return null;

    }

    

    private void reloadWorkItemsList() {

        List<WorkItemWrapper> result = new ArrayList<WorkItemWrapper>();

        for (Iterator<WorkItem> iterator = workItems.keySet().iterator(); iterator.hasNext(); ) {

            WorkItem workItem = iterator.next();

            result.add(new WorkItemWrapper(workItem));

        }

        workItemsList.setListData(result.toArray());

    }

    

    public void complete(WorkItem workItem, Map<String, Object> results) {

        WorkItemManager manager = workItems.get(workItem);

        if (manager != null) {

            manager.completeWorkItem(workItem.getId(), results);

            workItems.remove(workItem);

            reloadWorkItemsList();

        }

        selectButton.setEnabled(getSelectedWorkItem() != null);

    }

    

    public void abort(WorkItem workItem) {

        WorkItemManager manager = workItems.get(workItem);

        if (manager != null) {

            manager.abortWorkItem(workItem.getId());

            workItems.remove(workItem);

            reloadWorkItemsList();

        }

        selectButton.setEnabled(getSelectedWorkItem() != null);

    }

    

    public void abortWorkItem(WorkItem workItem, WorkItemManager manager) {

        workItems.remove(workItem);

        reloadWorkItemsList();

    }



    public void executeWorkItem(WorkItem workItem, WorkItemManager manager) {

        workItems.put(workItem, manager);

        reloadWorkItemsList();

    }



    private class WorkItemWrapper {

        

        private WorkItem workItem;

        

        public WorkItemWrapper(WorkItem workItem) {

            this.workItem = workItem;

        }

        

        public WorkItem getWorkItem() {

            return workItem;

        }

        

        public String toString() {

            return workItem.getName() + " [" + workItem.getId() + "]";

        }

    }

    

}