/*
 * [Coal.java]
 *
 * Summary: How long will US coal last given a rate of growth in consumption.
 *
 * Copyright: (c) 2009-2017 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:
 *  1.0 2009-11-29 initial version
 */
package com.mindprod.coal;

import com.mindprod.common18.CMPAboutJBox;
import com.mindprod.common18.Common18;
import com.mindprod.common18.FontFactory;
import com.mindprod.common18.HybridJ;
import com.mindprod.common18.JEButton;
import com.mindprod.common18.VersionCheck;

import javax.swing.JApplet;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JSpinner;
import javax.swing.JTextArea;
import javax.swing.SpinnerNumberModel;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import java.awt.Color;
import java.awt.Container;
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.text.DecimalFormat;

/**
 * How long will US coal last given a rate of growth in consumption.
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.0 2009-11-29 initial version
 * @since 2009-11-29
 */
public final class Coal extends JApplet
    {
    /**
     * height of Applet box in pixels. Does not include surrounding frame.
     */
    private static final int APPLET_HEIGHT = 162;

    /**
     * Width of Applet box in pixels.
     */
    private static final int APPLET_WIDTH = 664;

    private static final int FIRST_COPYRIGHT_YEAR = 2009;

    /**
     * undisplayed copyright notice
     */
    private static final String EMBEDDED_COPYRIGHT =
            "Copyright: (c) 2009-2017 Roedy Green, Canadian Mind Products, http://mindprod.com";

    private static final String RELEASE_DATE = "2009-11-29";

    private static final String TITLE_STRING =
            "Coal Extinction Calculator";

    /**
     * embedded version string.
     */
    private static final String VERSION_STRING = "1.0";

    /**
     * background colour for window.
     */
    private static final Color BACKGROUND_FOR_APP =
            new Color( 0xeeeeee/* grey */ );

    /**
     * background where for data entry where user enters a value.
     */
    private static final Color BACKGROUND_FOR_EDITABLE = Color.WHITE;

    /**
     * for instruction on how to use program
     */
    private static final Color BACKGROUND_FOR_INSTRUCTIONS = Color.WHITE;

    /**
     * for final result
     */
    private static final Color BACKGROUND_FOR_RESULT = Color.WHITE;

    /**
     * foreground colour for window text
     */
    private static final Color FOREGROUND_FOR_APP = Color.BLACK;

    /**
     * data entry text field colour
     */
    private static final Color FOREGROUND_FOR_ENTER = Color.BLACK;

    /**
     * for instruction on how to use program
     */
    private static final Color FOREGROUND_FOR_INSTRUCTIONS = new Color( 0x008000 );

    /**
     * for final result
     */
    private static final Color FOREGROUND_FOR_RESULT = Color.BLACK;

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

    /**
     * format for display and input of sale amount
     */
    private static final DecimalFormat PERCENT_FORMAT =
            new DecimalFormat( "#0.0" );

    /**
     * format for display and input of sale amount
     */
    private static final DecimalFormat YEARS_FORMAT =
            new DecimalFormat( "###,##0.0" );

    /**
     * for spinner
     */
    private static final Font FONT_FOR_EDITABLE_FIELDS;

    /**
     * for for titles and About buttons
     */
    private static final Font FONT_FOR_INSTRUCTIONS;

    /**
     * for final result
     */
    private static final Font FONT_FOR_RESULTS;

    /**
     * for for titles and About buttons
     */
    private static final Font FONT_FOR_TITLE;

    static
        {
        FONT_FOR_EDITABLE_FIELDS = FontFactory.build( "Monospaced", Font.BOLD, 15 );
        FONT_FOR_INSTRUCTIONS = FontFactory.build( "Dialog", Font.PLAIN, 15 );
        FONT_FOR_RESULTS = FontFactory.build( "Dialog", Font.PLAIN, 15 );
        FONT_FOR_TITLE = FontFactory.build( "Dialog", Font.BOLD, 16 );
        }

    /**
     * about
     */
    private JButton about;

    /**
     * label for annualConsumptionGrowthPercent
     */
    private JLabel annualConsumptionGrowthPercentLabel;

    /**
     * title of applet
     */
    private JLabel title;

    /**
     * annual growth in consumption as a percent
     */
    private JSpinner annualConsumptionGrowthPercent;

    /**
     * first line of result as a sentence.
     */
    private JTextArea result;

    /**
     * formats output of  annualConsumptionGrowthPercent.
     */
    private SpinnerNumberModel annualConsumptionGrowthPercentNumberModel;

    /**
     * constructor
     */
    public Coal()
        {
        }

    /**
     * compute how many years are left before US coal runs out, given a presumed rate of growth in consumption
     */
    private void compute()
        {
        final double percent = annualConsumptionGrowthPercentNumberModel.getNumber().doubleValue(); // historic 2.86,
        // pop 3%
        final double rate = percent / 100;   // +ve mean growing, -ve means shrinking
        // data for US coal annual energy review 1991, US Dept of energy
        final double reserve = 273E9; /** short tons reserve of extractable coal in USA,
         http://www.clean-energy.us/facts/coal.htm*/
        final double extraction = 986E6 / .86; /** tons per yer in USA in 2001 */
        // formula from http://climatechange.flinders.edu.au/various%20attachments/Bartlett%20-%20NRR%5B1%5D.pdf
        // Math.log1P is more accurate that adding one to the argument.
        final double extinctionYears = 1. / rate * Math.log1p( rate * reserve / extraction );
        if ( rate > 0 )
            {
            result.setText( "If coal consumption grows at "
                            + PERCENT_FORMAT.format( percent )
                            + "% per annum, coal in the USA will run out in "
                            + YEARS_FORMAT.format( extinctionYears )
                            + " years." );
            }
        else if ( rate < 0 )
            {
            if ( Double.isNaN( extinctionYears ) )
                {
                result.setText( "If coal consumption shrinks at "
                                + PERCENT_FORMAT.format( -percent )
                                + "% per annum, coal in the USA would not run out." );
                }
            else
                {
                result.setText( "If coal consumption shrinks at "
                                + PERCENT_FORMAT.format( -percent )
                                + "% per annum, coal in the USA will run out in "
                                + YEARS_FORMAT.format( extinctionYears )
                                + " years." );
                }
            }
        else
            {
            result.setText( "If annual coal consumption does not change, the USA will run out of coal in "
                            + YEARS_FORMAT.format( reserve / extraction )
                            + " years." );
            }
        }

    /**
     * create gui components
     */
    private void createComponents()
        {
        title = new JLabel( TITLE_STRING + " " + VERSION_STRING );
        title.setFont( FONT_FOR_TITLE );
        title.setForeground( FOREGROUND_FOR_TITLE );
        // leave background app background
        about = new JEButton( "About" );
        about.setToolTipText( "About " + TITLE_STRING + " " + VERSION_STRING );
        annualConsumptionGrowthPercentLabel = new JLabel(
                "Select assumed annual growth rate percentage in coal consumption.",
                JLabel.RIGHT );
        annualConsumptionGrowthPercentLabel.setFont( FONT_FOR_INSTRUCTIONS );
        annualConsumptionGrowthPercentLabel.setBackground( BACKGROUND_FOR_INSTRUCTIONS );
        annualConsumptionGrowthPercentLabel.setForeground( FOREGROUND_FOR_INSTRUCTIONS );
        annualConsumptionGrowthPercent = new JSpinner();
        annualConsumptionGrowthPercent.setFont( FONT_FOR_EDITABLE_FIELDS );
        annualConsumptionGrowthPercent.setBackground( BACKGROUND_FOR_EDITABLE );
        annualConsumptionGrowthPercent.setForeground( FOREGROUND_FOR_ENTER );
        annualConsumptionGrowthPercent.setValue( 2.9d );
        // bounds on spinner
        annualConsumptionGrowthPercentNumberModel =
                new SpinnerNumberModel( /* initial value */ 2.9d,
                        /* min */ -0.5d,
                        /* max */ +25.0d,
                        /* step */ 0.1d );
        annualConsumptionGrowthPercent.setModel( annualConsumptionGrowthPercentNumberModel );
        result = new JTextArea( 2, 40 );
        result.setEditable( false );
        // provide some space around the inside
        result.setMargin( new Insets( 4, 4, 4, 4 ) );
        // automatically wrap lines
        result.setLineWrap( true );
        result.setWrapStyleWord( true );
        result.setFont( FONT_FOR_RESULTS );
        result.setBackground( BACKGROUND_FOR_RESULT );
        result.setForeground( FOREGROUND_FOR_RESULT );
        }

    /**
     * hook up the listeners
     */
    private void hookListeners()
        {
        // engage the listeners
        about.addActionListener( new ActionListener()
            {
            public void actionPerformed( ActionEvent e )
                {
                // open about box frame
                new CMPAboutJBox( TITLE_STRING,
                        VERSION_STRING,
                        "Calculates how long coal will last presuming",
                        "different rates of growth in demand.",
                        "freeware",
                        RELEASE_DATE,
                        FIRST_COPYRIGHT_YEAR,
                        "Roedy Green",
                        "COAL",
                        "1.8" );
                }
            } );
        annualConsumptionGrowthPercentNumberModel.addChangeListener( new ChangeListener()
            {
            /**
             * }
             * spinner changed value
             * @param e event from spinner
             */
            public void stateChanged( ChangeEvent e )
                {
                compute();
                } // end actionPerformed
            } );
        // don't also need  annualConsumptionGrowthPercent.addChangeListener
        }

    /**
     * layout the components
     *
     * @param contentPane where to add components
     */
    private void layoutGridBag( Container contentPane )
        {
        // basic layout:
        // 0-----0------------------------------------ 1-------
        // 0 -----------TITLE------------------------ -----about
        // 1 --consumption % ----------------------   consumption
        // 2 -- result-----------------------------------------.
        // x y w h wtx wty anchor fill T L B R padx pady
        contentPane.add( title,
                new GridBagConstraints( 0,
                        0,
                        1,
                        1,
                        0.0,
                        0.0,
                        GridBagConstraints.WEST,
                        GridBagConstraints.NONE,
                        new Insets( 10, 10, 0, 5 ),
                        0,
                        0 )
        );
        // x y w h wtx wty anchor fill T L B R padx pady
        contentPane.add( about,
                new GridBagConstraints( 1,
                        0,
                        1,
                        1,
                        0.0,
                        0.0,
                        GridBagConstraints.EAST,
                        GridBagConstraints.NONE,
                        new Insets( 10, 5, 5, 10 ),
                        10,
                        2 )
        );
        // x y w h wtx wty anchor fill T L B R padx pady
        contentPane.add( annualConsumptionGrowthPercentLabel,
                new GridBagConstraints( 0,
                        1,
                        1,
                        1,
                        0.0,
                        0.0,
                        GridBagConstraints.EAST,
                        GridBagConstraints.NONE,
                        new Insets( 0, 10, 5, 5 ),
                        0,
                        0 )
        );
        // x y w h wtx wty anchor fill T L B R padx pady
        contentPane.add( annualConsumptionGrowthPercent,
                new GridBagConstraints( 1,
                        1,
                        1,
                        1,
                        0.0,
                        0.0,
                        GridBagConstraints.EAST,
                        GridBagConstraints.NONE,
                        new Insets( 0, 5, 5, 10 ),
                        20,
                        0 )
        );
        // x y w h wtx wty anchor fill T L B R padx pady
        contentPane.add( result,
                new GridBagConstraints( 0,
                        3,
                        2,
                        1,
                        1.0,
                        1.0,
                        GridBagConstraints.WEST,
                        GridBagConstraints.BOTH,
                        new Insets( 5, 10, 10, 10 ),
                        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 Coal(),
                TITLE_STRING + " " + VERSION_STRING,
                APPLET_WIDTH,
                APPLET_HEIGHT );
        } // end main

    /**
     * Called by the browser or Applet viewer to inform
     * this Applet that it is being reclaimed and that it should destroy
     * any resources that it has allocated.
     */
    @Override
    public void destroy()
        {
        about = null;
        annualConsumptionGrowthPercent = null;
        annualConsumptionGrowthPercentLabel = null;
        annualConsumptionGrowthPercentNumberModel = null;
        result = null;
        title = null;
        }

    /**
     * Called by the browser or Applet viewer to inform
     * this Applet that it has been loaded into the system.
     */
    @Override
    public void init()
        {
        if ( !VersionCheck.isJavaVersionOK( 1, 8, 0, this ) )
            {
            return;
            }
        Common18.setLaf();
        Container contentPane = this.getContentPane();
        contentPane.setBackground( BACKGROUND_FOR_APP );
        contentPane.setForeground( FOREGROUND_FOR_APP );
        contentPane.setLayout( new GridBagLayout() );
        createComponents();
        layoutGridBag( contentPane );
        hookListeners();
        compute();
        this.validate();
        this.setVisible( true );
        } // end init
    }