/*
 * [Masker.java]
 *
 * Summary: Produces pngs with email address in them to deter spam harvesting from websites.
 *
 * Copyright: (c) 2005-2017 Roedy Green, Canadian Mind Products, http://mindprod.com
 *
 * Licence: This software may be copied and used freely for any purpose but military.
 *          http://mindprod.com/contact/nonmil.html
 *
 * Requires: JDK 1.8+
 *
 * Created with: JetBrains IntelliJ IDEA IDE http://www.jetbrains.com/idea/
 *
 * Version History:
 *  1.2 2005-06-24 documents align="top" to handle gif and text alignment.
 *                 RELEASE_DATE, made vars static final.
 *  1.3 2006-03-06 reformat with IntelliJ, add Javadoc.
 *  1.4 2007-07-18 standard swing buttons. Courier removed as preferred font.
 *                 trim email entered, change name generated to not use mailto.
 *                 Fix problem with background not getting cleared all the time.
 *                 Changed list of preferred fonts.
 *  1.5 2008-01-22 JDK 1.3 to 1.4 since that is needed for Preferences.
 *  1.6 2008-03-11 add build number to title.
 *  1.7 2009-04-04 get rid of artifacts on screen. Suggest lower case filename.
 *  1.8 2009-04-04 Mask, command line version of Masker.
 *  1.9 2010-03-23 user selectable look and feel.
 */
package com.mindprod.masker;

import com.mindprod.common18.Build;
import com.mindprod.common18.CMPAboutJBox;
import com.mindprod.common18.FontFactory;
import com.mindprod.common18.HybridJ;
import com.mindprod.common18.JEButton;
import com.mindprod.common18.Laf;
import com.mindprod.common18.VersionCheck;

import javax.swing.JApplet;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JTextField;
import javax.swing.event.CaretEvent;
import javax.swing.event.CaretListener;
import java.awt.Color;
import java.awt.Container;
import java.awt.Font;
import java.awt.GraphicsEnvironment;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Arrays;
import java.util.HashSet;

/**
 * Produces pngs with email address in them to deter spam harvesting from websites.
 * <p/>
 * This is both an Applet and a standalone application.
 * <p/>
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.9 2010-03-23 user selectable look and feel.
 * @noinspection FieldCanBeLocal
 * @since 2005
 */
public final class Masker extends JApplet
    {
    /**
     * height of Applet in pixels. Does not include bar at top, but does include menu bar.
     */
    private static final int APPLET_HEIGHT = 275;

    /**
     * Width of Applet in pixels.
     */
    private static final int APPLET_WIDTH = 636;

    private static final int FIRST_COPYRIGHT_YEAR = 2005;

    /**
     * font size to use in the generated PNG images.
     */
    private static final int pngFontSize = 18;

    /**
     * undisplayed copyright notice
     *
     * @noinspection UnusedDeclaration
     */
    private static final String EMBEDDED_COPYRIGHT =
            "Copyright: (c) 2005-2017 Roedy Green, Canadian Mind Products, http://mindprod.com";

    /**
     * date this version released.
     */
    private static final String RELEASE_DATE = "2010-03-23";

    /**
     * Title of the Applet
     */
    private static final String TITLE_STRING = "CMP Email Masker";

    /**
     * Version of the Applet
     */
    private static final String VERSION_STRING = "1.9";

    /**
     * Best fonts to use. Takes the first one that is supported on the given system. For official names
     * see http://mindprod.com/fontshower.html
     */
    private static final String[] pngFonts = new String[] {
            "Tiresias PCfont Z",
            "Tiresias PCfont",
            "TiresiasScreenfont",
            "Verdana",
            "Lucida Console",
            "Lucida Sans" };// if none of these supported, will use Dialog.

    /**
     * Applet background
     */
    private static final Color BACKGROUND_FOR_APPLET = new Color( 0xfff4ff );

    /**
     * background colour for input fields
     */
    private static final Color BACKGROUND_FOR_INPUT = new Color( 0xffffff );

    /**
     * default foreground colour for images
     */
    private static final Color FOREGROUND_FOR_DEFAULT = new Color( 0x777777 )/* grey */;

    /**
     * foreground colour for input fields
     */
    private static final Color FOREGROUND_FOR_INPUT = new Color( 0x1e90ff )/* dodger blue */;

    private static final Color FOREGROUND_FOR_LABEL = new Color( 0x0000b0 );

    /**
     * for titles
     */
    private static final Color FOREGROUND_FOR_TITLE = new Color( 0xdc143c );

    /**
     * default transparent background colour for images.
     */
    private static final Color transparent = new Color( 0x00ffffff, true );

    /**
     * font for input fields
     */
    private static final Font FONT_FOR_EDITABLE_FIELDS = FontFactory.build( "Dialog", Font.BOLD, 17 );

    /**
     * for for titles and About buttons
     */
    private static final Font FONT_FOR_TITLE = FontFactory.build( "Dialog", Font.BOLD, 16 );

    /**
     * for for titles and About buttons
     */
    private static final Font FONT_FOR_TITLE2 = FontFactory.build( "Dialog", Font.PLAIN, 14 );

    /**
     * HashSet of names of all supported font families
     */
    private static final HashSet<String> allFontFamilies;

    static
        {
        String[] names = ( GraphicsEnvironment.getLocalGraphicsEnvironment() )
                .getAvailableFontFamilyNames();
        // convert to lower case for case-insensitive lookup
        for ( int i = 0, n = names.length; i < n; i++ )
            {
            names[ i ] = names[ i ].toLowerCase();
            }
        allFontFamilies = new HashSet<>( Arrays.asList( names ) );
        }

    /**
     * save button
     */
    private JButton save;

    /**
     * "email:"
     */
    private JLabel emailLabel;

    /**
     * instruction on how to use the program
     */
    private JLabel instructions;

    /**
     * title on screen
     */
    private JLabel title;

    /**
     * title, second line
     */
    private JLabel title2;

    /**
     * where you fill in email address on screen
     */
    private JTextField email;

    /**
     * where PNG image is displayed on screen.
     */
    private ShroudedImage png;

    /**
     * Constructor
     */
    public Masker()
        {
        }

    /**
     * Get the most preferred supported font from a list
     *
     * @param preferredFontNames list of font names, best one first.
     * @param fontStyle          e.g. Font.PLAIN
     * @param fontSize           size of font in points.
     *
     * @return best font that is supported, or a Dialog font if none are.
     * @noinspection SameParameterValue
     */
    private static Font bestFont( String[] preferredFontNames,
                                  int fontStyle,
                                  int fontSize )
        {
        // find first font in that is supported
        for ( String preferredFontName : preferredFontNames )
            {
            if ( allFontFamilies.contains( preferredFontName.toLowerCase() ) )
                {
                return FontFactory.build( preferredFontName, fontStyle, fontSize );
                }
            } // end for
        return FontFactory.build( "Dialog", fontStyle, fontSize );
        }

    /**
     * allocate all the components
     */
    private void buildComponents()
        {
        title = new JLabel( TITLE_STRING + " " + VERSION_STRING );
        title.setForeground( FOREGROUND_FOR_TITLE );
        title.setFont( FONT_FOR_TITLE );
        title2 = new JLabel(
                "released:" +
                RELEASE_DATE +
                " build:" +
                Build.BUILD_NUMBER
        );
        title2.setFont( FONT_FOR_TITLE2 );
        title2.setForeground( FOREGROUND_FOR_TITLE );
        emailLabel = new JLabel( "email:" );
        emailLabel.setForeground( FOREGROUND_FOR_LABEL );
        email = new JTextField( "roedyg@mindprod.com", 40 );
        email.setEditable( true );
        email.setMargin( new Insets( 2, 2, 2, 2 ) );
        email.setFont( FONT_FOR_EDITABLE_FIELDS );
        email.setBackground( BACKGROUND_FOR_INPUT );
        email.setForeground( FOREGROUND_FOR_INPUT );
        email.addCaretListener( new CaretListener()
            {
            /**
             * Called when the caret position is updated.
             * @param e the caret event
             */
            public void caretUpdate( CaretEvent e )
                {
                // text changed
                png.setText( email.getText().trim() );
                validate();
                }
            } );
        png = new ShroudedImage( email.getText().trim() );
        png.setForeground( FOREGROUND_FOR_DEFAULT );
        png.setBackground( transparent );
        png.setFont( bestFont( pngFonts, Font.PLAIN, pngFontSize ) );
        save = new JEButton( "Save" );
        save.setToolTipText( "Save Email image as a PNG file" );
        save.addActionListener( new ActionListener()
            {
            /**
             * called when the save button hit.
             * @param e not used.
             */
            public void actionPerformed( ActionEvent e )
                {
                // save hit
                String text = email.getText().trim();
                png.setText( text );
                int place = text.indexOf( '@' );
                if ( place < 0 )
                    {
                    // take whole thing.
                    place = text.length();
                    }
                String saveName = text.substring( 0, place ).toLowerCase() + ".png";
                png.saveImage( saveName );
                }
            } );
        instructions = new JLabel(
                "Fill in your email address and hit Save to create a png image of your email address." );
        instructions.setForeground( FOREGROUND_FOR_LABEL );
        }

    /**
     * build a menu with Look & Feel and About across the top
     */
    private void buildMenu()
        {
        // turn on anti-alias
        System.setProperty( "swing.aatext", "true" );
        final JMenuBar menubar = new JMenuBar();
        setJMenuBar( menubar );
        final JMenu lafMenu = Laf.buildLookAndFeelMenu();
        if ( lafMenu != null )
            {
            menubar.add( lafMenu );
            }
        final JMenu menuHelp = new JMenu( "Help" );
        menubar.add( menuHelp );
        final JMenuItem aboutItem = new JMenuItem( "About" );
        menuHelp.add( aboutItem );
        aboutItem.addActionListener( new ActionListener()
            {
            public void actionPerformed( ActionEvent e )
                {
                // open about frame
                new CMPAboutJBox( TITLE_STRING,
                        VERSION_STRING,
                        "Creates png files (like gifs but smaller)",
                        "to hide your email address from spam harvesters.",
                        "freeware",
                        RELEASE_DATE,
                        FIRST_COPYRIGHT_YEAR,
                        "Roedy Green",
                        "MASKER",
                        "1.8" );
                }
            } );
        }

    /**
     * layout fields in GridBag
     *
     * @param contentPane where to place the components
     */
    private void layoutFields( Container contentPane )
        {
        // 0________1_____ 2
        // title ------------- 0
        // title2 ------------ 1
        // label email address 2
        // what png looks like 3
        // -------SAVE ------- 4
        // instructions        5
        //
        // x y w h wtx wty anchor fill T L B R padx pady
        contentPane.add( title,
                new GridBagConstraints( 1,
                        0,
                        1,
                        1,
                        0.0,
                        0.0,
                        GridBagConstraints.WEST,
                        GridBagConstraints.NONE,
                        new Insets( 5, 2, 0, 2 ),
                        0,
                        0 )
        );
        // x y w h wtx wty anchor fill T L B R padx pady
        contentPane.add( title2,
                new GridBagConstraints( 1,
                        1,
                        1,
                        1,
                        0.0,
                        0.0,
                        GridBagConstraints.WEST,
                        GridBagConstraints.NONE,
                        new Insets( 0, 2, 0, 2 ),
                        0, 0 )
        );
        // x y w h wtx wty anchor fill T L B R padx pady
        contentPane.add( emailLabel,
                new GridBagConstraints( 0,
                        2,
                        1,
                        1,
                        0.0,
                        0.0,
                        GridBagConstraints.EAST,
                        GridBagConstraints.NONE,
                        new Insets( 7, 5, 0, 5 ),
                        0,
                        0 )
        );
        // x y w h wtx wty anchor fill T L B R padx pady
        contentPane.add( email,
                new GridBagConstraints( 1,
                        2,
                        2,
                        1,
                        0.0,
                        0.0,
                        GridBagConstraints.WEST,
                        GridBagConstraints.HORIZONTAL,
                        new Insets( 7, 2, 0, 5 ),
                        0,
                        0 )
        );
        // x y w h wtx wty anchor fill T L B R padx pady
        contentPane.add( png,
                new GridBagConstraints( 1,
                        3,
                        2,
                        1,
                        0.0,
                        0.0,
                        GridBagConstraints.WEST,
                        GridBagConstraints.NONE,
                        new Insets( 7, 2, 0, 5 ),
                        0,
                        0 )
        );
        // x y w h wtx wty anchor fill T L B R padx pady
        contentPane.add( save,
                new GridBagConstraints( 2,
                        4,
                        1,
                        1,
                        0.0,
                        0.0,
                        GridBagConstraints.EAST,
                        GridBagConstraints.NONE,
                        new Insets( 5, 2, 0, 5 ),
                        0,
                        0 )
        );
        // x y w h wtx wty anchor fill T L B R padx pady
        contentPane.add( instructions,
                new GridBagConstraints( 1,
                        5,
                        2,
                        1,
                        0.0,
                        0.0,
                        GridBagConstraints.WEST,
                        GridBagConstraints.NONE,
                        new Insets( 5, 2, 5, 5 ),
                        0,
                        0 )
        );
        }

    /**
     * Allow this Applet to run as as application as well.
     *
     * @param args command line arguments ignored.
     */
    public static void main( String args[] )
        {
        HybridJ.fireup( new Masker(),
                TITLE_STRING + " " + VERSION_STRING,
                APPLET_WIDTH,
                APPLET_HEIGHT );
        } // end main

    /**
     * Called by the browser or Applet viewer to inform
     * this Applet that it has been loaded into the system.
     */
    @Override
    public void init()
        {
        Container contentPane = this.getContentPane();
        if ( !VersionCheck.isJavaVersionOK( 1, 7, 0, contentPane ) )
            {
            // effectively abort
            return;
            }
        buildMenu(); // also initial L&F
        contentPane.setLayout( new GridBagLayout() );
        contentPane.setBackground( BACKGROUND_FOR_APPLET );
        buildComponents();
        layoutFields( contentPane );
        this.validate();
        this.setVisible( true );
        }
    } // end Masker