/**
 * Copyright (c) 2011, The University of Southampton and the individual contributors.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 *   *  Redistributions of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 *
 *   *  Redistributions in binary form must reproduce the above copyright notice,
 *      this list of conditions and the following disclaimer in the documentation
 *      and/or other materials provided with the distribution.
 *
 *   *  Neither the name of the University of Southampton nor the names of its
 *      contributors may be used to endorse or promote products derived from this
 *      software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/**
 *
 */
package org.openimaj.demos;

import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.lang.reflect.Method;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.Vector;

import javax.swing.DefaultListCellRenderer;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTabbedPane;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;

import org.apache.commons.io.IOUtils;
import org.openimaj.util.processes.JavaProcess;
import org.openimaj.util.processes.ProcessException;
import org.reflections.Reflections;
import org.xhtmlrenderer.simple.XHTMLPanel;
import org.xhtmlrenderer.simple.extend.XhtmlNamespaceHandler;

import com.uwyn.jhighlight.renderer.JavaXhtmlRenderer;

/**
 * This class provides a means for listing and running demos that have been
 * automatically scanned from the classpath. The class looks for types that are
 * annotated with the {@link Demo} annotation and displays these in a list. The
 * source code should be available as a resource to this class, so that the
 * source can be loaded and displayed.
 * <p>
 * Icons for demos should be resized so that they are 32x32 pixels and they
 * should ideally be transparent PNGs.
 * <p>
 * Screenshots should be PNGs and should be resized to be 250 pixels wide.
 *
 * @author David Dupplaw (dpd@ecs.soton.ac.uk)
 * @created 2nd November 2011
 */
public class Demos {
        /**
         * The location of the source code on the web. The class will look for the
         * source code at this location if it cannot find it on disk.
         */
        public final static String OPENIMAJ_SRC_URL =
                        "http://svn.code.sf.net/p/openimaj/code/trunk/demos/demos/src/main/java/";

        /**
         * This is the display for the demo runner.
         *
         * @author David Dupplaw (dpd@ecs.soton.ac.uk)
         * @created 2nd November 2011
         */
        protected class DemoRunnerPanel extends JPanel {
                /** */
                private static final long serialVersionUID = 1L;

                private JTabbedPane demoTabs = new JTabbedPane();
                private Map<DemoPackage, JList<DemoObject>> demoTabMap =
                                new HashMap<DemoPackage, JList<DemoObject>>();
                private Map<DemoPackage, Vector<DemoObject>> demos =
                                new HashMap<DemoPackage, Vector<DemoObject>>();
                private JLabel demoTitle = new JLabel();
                private JLabel demoAuthor = new JLabel();
                private JLabel demoScreen = new JLabel();
                private JLabel demoDescription = new JLabel();
                private JButton demoRunButton = new JButton("Run Demo");
                private JButton demoSourceButton = new JButton("See Source Code");

                private DemoObject lastSelectedDemo = null;

                /**
                 * Default constructor that sets up the display
                 */
                public DemoRunnerPanel() {
                        setLayout(new GridBagLayout());
                        setBackground(Color.white);

                        final GridBagConstraints gbc = new GridBagConstraints();
                        gbc.gridx = gbc.gridy = 0;
                        gbc.gridwidth = 1;
                        gbc.fill = GridBagConstraints.BOTH;
                        gbc.weightx = gbc.weighty = 1;

                        // Set up a banner with the OpenIMAJ logo
                        final JLabel openImajLogo = new JLabel(new ImageIcon(
                                        Demos.class.getResource("/org/openimaj/demos/OpenIMAJ.png")));
                        gbc.gridx = 1;
                        gbc.weighty = 0;
                        add(openImajLogo, gbc);

                        // Set up the list of demos down the left-hand side of the display
                        gbc.gridx = 0;
                        gbc.gridy++;
                        final int y = gbc.gridy;
                        gbc.weighty = 1;
                        gbc.insets = new Insets(8, 8, 8, 8);
                        add(demoTabs, gbc);

                        // Set up the panel down the right-hand side that displays
                        // information about each demo.
                        final JPanel p = new JPanel(new GridBagLayout());
                        p.setOpaque(false);
                        p.setPreferredSize(new Dimension(250, 600));
                        p.setMaximumSize(new Dimension(250, 6000));
                        p.setMinimumSize(new Dimension(250, 100));
                        gbc.weighty = 0;
                        gbc.fill = GridBagConstraints.BOTH;
                        gbc.insets = new Insets(0, 0, 0, 0);
                        p.add(demoTitle, gbc);
                        gbc.gridy++;
                        p.add(demoAuthor, gbc);
                        gbc.gridy++;
                        gbc.insets = new Insets(6, 0, 6, 0);
                        p.add(demoDescription, gbc);
                        gbc.gridy++;
                        p.add(demoScreen, gbc);
                        gbc.gridy++;
                        gbc.insets = new Insets(1, 0, 1, 0);
                        p.add(demoSourceButton, gbc);
                        gbc.gridy++;
                        p.add(demoRunButton, gbc);

                        // Add a padding panel to the right-hand panel, so that the
                        // text does spread out over the panel in an ugly way.
                        gbc.weighty = 1;
                        gbc.gridy++;
                        final JPanel paddingPanel = new JPanel();
                        paddingPanel.setOpaque(false);
                        p.add(paddingPanel, gbc);

                        gbc.gridx++;
                        gbc.gridy = y;
                        gbc.weighty = 1;
                        gbc.weightx = 0;
                        gbc.insets = new Insets(8, 8, 8, 8);
                        add(p, gbc);

                        demoTabs.addChangeListener(new ChangeListener()
                        {
                                @Override
                                public void stateChanged(ChangeEvent e)
                                {
                                        @SuppressWarnings("unchecked")
                                        final JList<DemoObject> d = (JList<DemoObject>) ((JScrollPane) demoTabs.getSelectedComponent())
                                        .getViewport().getComponent(0);
                                        if (d.getSelectedValue() != null)
                                                updateDisplay(d.getSelectedValue());
                                }
                        });

                        demoTitle.setFont(new Font("Arial", Font.BOLD, 14));
                        demoDescription.setFont(new Font("Arial", Font.PLAIN, 10));

                        // When run button is pressed, run the selected demo
                        demoRunButton.addActionListener(new ActionListener()
                        {
                                @Override
                                public void actionPerformed(ActionEvent e)
                                {
                                        try
                                        {
                                                final DemoObject obj = lastSelectedDemo;
                                                if (obj != null)
                                                {
                                                        // runDemo( obj.demoClass, obj.annotation );
                                                        runDemoNewJVM(obj.demoClass, obj.annotation);
                                                }
                                        }
                                        catch (final Exception e1)
                                        {
                                                e1.printStackTrace();
                                        }
                                }
                        });
                        demoRunButton.setEnabled(false);

                        // When the source button is pressed, display the source of the
                        // selected demo.
                        demoSourceButton.addActionListener(new ActionListener()
                        {
                                @Override
                                public void actionPerformed(ActionEvent e)
                                {
                                        try
                                        {
                                                final DemoObject obj = lastSelectedDemo;

                                                // Get the resource where the source code is stored
                                                final String resource = "/" + obj.demoClass.getCanonicalName().
                                                                replace(".", "/") + ".java";
                                                System.out.println(resource);

                                                // Read the source code from the resource
                                                InputStream stream = Demos.class.getResourceAsStream(resource);

                                                // If the stream is null it means the code isn't
                                                // available.
                                                // If that happens, we should try to read the source
                                                // from
                                                // the svn on openimaj.org.
                                                if (stream == null)
                                                {
                                                        final URL u = new URL(OPENIMAJ_SRC_URL + resource);
                                                        stream = u.openStream();
                                                }

                                                final String source = IOUtils.toString(stream, "ISO-8859-1");
                                                // "<html><head></head><body><h1>Hello</h1></body></html>";

                                                stream.close();

                                                // Syntax highlight the source code in XHTML
                                                final JavaXhtmlRenderer r = new JavaXhtmlRenderer();
                                                final String h = r.highlight(obj.demoClass.getSimpleName(),
                                                                source, "ISO-8859-1", false);

                                                // Render the XHTML to an XHTML panel
                                                final XHTMLPanel p = new XHTMLPanel();
                                                p.setDocumentFromString(h, resource, new XhtmlNamespaceHandler());

                                                // Stick the XHTMLPanel in a frame
                                                final JFrame f = new JFrame();
                                                f.setSize(800, 600);
                                                f.setLocationRelativeTo(null);
                                                f.getContentPane().add(new JScrollPane(p));
                                                f.setVisible(true);
                                        }
                                        catch (final IOException e1)
                                        {
                                                e1.printStackTrace();
                                        }
                                }
                        });
                        demoSourceButton.setEnabled(false);
                }

                /**
                 * Updates the information display of the demo.
                 *
                 * @param dObj
                 *            The {@link DemoObject} for the selected demo
                 */
                private void updateDisplay(DemoObject dObj) {
                        demoTitle.setText(dObj.annotation.title());
                        demoDescription.setText("<html><p>" + dObj.annotation.description() + "</p></html>");
                        demoAuthor.setText("By " + dObj.annotation.author());

                        if (dObj.annotation.screenshot() != null)
                                demoScreen.setIcon(new ImageIcon(
                                                Demos.class.getResource(dObj.annotation.screenshot())));
                        else
                                demoScreen.setIcon(null);
                }

                /**
                 * Add a demo to the list
                 *
                 * @param obj
                 *            The object representing the demo
                 */
                public void addDemo(DemoObject obj) {
                        JList<DemoObject> d = demoTabMap.get(obj.pkg);

                        if (d == null) {
                                final JList<DemoObject> r = new JList<DemoObject>();
                                demoTabMap.put(obj.pkg, r);
                                d = r;

                                // When the list is clicked upon, update the demo information
                                d.addListSelectionListener(new ListSelectionListener()
                                {
                                        @Override
                                        public void valueChanged(ListSelectionEvent e)
                                        {
                                                demoRunButton.setEnabled(true);
                                                demoSourceButton.setEnabled(true);
                                                updateDisplay(lastSelectedDemo =
                                                                r.getSelectedValue());
                                        }
                                });
                                d.setCellRenderer(new IconListRenderer());

                                demoTabs.addTab(
                                                obj.pkg == null ? "Demos" : obj.pkg.title(),
                                                                new JScrollPane(d));
                        }

                        Vector<DemoObject> dd = demos.get(obj.pkg);

                        if (dd == null)
                                demos.put(obj.pkg, dd = new Vector<Demos.DemoObject>());

                        dd.add(obj);
                        d.removeAll();
                        d.setListData(dd);

                        revalidate();
                }
        }

        /**
         * Used for each demo in the list.
         *
         * @author David Dupplaw (dpd@ecs.soton.ac.uk)
         * @created 2nd November 2011
         */
        protected class DemoObject {
                public Demo annotation;
                public Class<?> demoClass;
                public DemoPackage pkg;

                public DemoObject(Class<?> c) {
                        annotation = c.getAnnotation(Demo.class);
                        demoClass = c;
                        pkg = demoClass.getPackage().getAnnotation(DemoPackage.class);
                }

                @Override
                public String toString() {
                        return annotation.title();
                }
        }

        /**
         * A list renderer that adds an icon to the label.
         *
         * @author David Dupplaw (dpd@ecs.soton.ac.uk)
         * @created 3rd November 2011
         */
        protected class IconListRenderer extends DefaultListCellRenderer {
                private static final long serialVersionUID = 1L;

                @Override
                public Component getListCellRendererComponent(JList<?> list, Object value,
                                int index, boolean isSelected, boolean cellHasFocus)
                {
                        final JLabel l = (JLabel) super.getListCellRendererComponent(
                                        list, value, index, isSelected, cellHasFocus);

                        final DemoObject o = (DemoObject) value;
                        if (o.annotation.icon() != null) {
                                URL u = getClass().getResource(o.annotation.icon());
                                if (u == null)
                                        u = getClass().getResource("/defaults/demo.png");
                                l.setIcon(new ImageIcon(u));
                        }

                        return l;
                }
        }

        /** The panel that will be used to display the list of dmeos */
        private DemoRunnerPanel panel = new DemoRunnerPanel();

        /**
         * Default constructor
         */
        public Demos() {
                try {
                        // Get a list of the available demos
                        final Set<Class<?>> c = findDemos();

                        // Add the demos to the list
                        for (final Class<?> cc : c)
                                panel.addDemo(new DemoObject(cc));

                        // Show the menu
                        final JFrame f = new JFrame();
                        f.getContentPane().add(panel);
                        f.setSize(800, 600);
                        f.setLocationRelativeTo(null);
                        f.setVisible(true);
                        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                } catch (final Exception e) {
                        e.printStackTrace();
                }
        }

        /**
         * Finds the class files that have been annotated with the @Demo annotation.
         */
        private Set<Class<?>> findDemos() {
                final Reflections reflections = new Reflections("org.openimaj.demos");
                return reflections.getTypesAnnotatedWith(Demo.class);
        }

        /**
         * Given a demo class file, will instantiate the demo and run its main
         * method.
         *
         * @param clazz
         *            The demo class file
         */
        @SuppressWarnings("unused")
        private void runDemo(Class<?> clazz, Demo annotation) throws Exception {
                try {
                        final Method main = clazz.getDeclaredMethod("main", String[].class);
                        System.out.println(main);
                        main.invoke(null, (Object) annotation.arguments());
                } catch (final Throwable t) {
                        final String msg = String.format("Unexpected problem: %s",
                                        getStackTrace(t.getCause()));
                        JOptionPane.showMessageDialog(null, msg);
                        throw new Exception(t);
                }
        }

        /**
         * Given a demo class file, instantiate the demo and run its main method in
         * a new JVM
         *
         * @param clazz
         *            The demo class file
         */
        private void runDemoNewJVM(final Class<?> clazz, Demo annotation) throws Exception {
                final String[] jvmArgs = annotation.vmArguments();
                final String[] appArgs = annotation.arguments();

                new Thread() {
                        @Override
                        public void run() {
                                try {
                                        JavaProcess.runProcess(clazz, jvmArgs, appArgs);
                                } catch (final ProcessException e) {
                                        e.printStackTrace();
                                }
                        };
                }.start();
        }

        /**
         * Returns a string of a stack trace.
         *
         * @param aThrowable
         *            The throwable to get a string for
         * @return The throwable's stack as a string
         */
        private static String getStackTrace(Throwable aThrowable) {
                final Writer result = new StringWriter();
                final PrintWriter printWriter = new PrintWriter(result);
                aThrowable.printStackTrace(printWriter);
                return result.toString().substring(0, 1024) + "...";
        }

        /**
         * Default main just starts the demo system.
         *
         * @param args
         */
        public static void main(String[] args) {
                new Demos();
        }
}