/*
 * [DateSpinner.java]
 *
 * Summary: GUI JComponent to enter a yyyy-mm-dd value with a Spinner similar to a JSpinner.
 *
 * Copyright: (c) 2011-2017 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 2011-02-26 initial version
 *  1.1 2011-03-22 bugs fixed.
 */
package com.mindprod.spinner;

import com.mindprod.common18.BigDate;
import com.mindprod.fastcat.FastCat;

import javax.swing.JPanel;
import javax.swing.JSpinner;
import javax.swing.SpinnerNumberModel;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.event.EventListenerList;
import java.awt.FlowLayout;

import static java.lang.System.*;

/**
 * GUI JComponent to enter a yyyy-mm-dd value with a Spinner similar to a JSpinner.
 * <p/>
 * It is implemented internally as three JSpinners, one each for yyyy, mm, dd that act like one.
 * It does not use a SpinnerModel. The equivalent SpinnerModel methods work directly on the DataSpinner.
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.1 2011-03-22 bugs fixed
 * @since 2011-02-26
 */
public class DateSpinner extends JPanel implements ChangeListener
    {
    /**
     * do you want extra validation
     */
    private static final boolean DEBUGGING = false;

    /**
     * latest date we can handle
     */
    private static final BigDate HIGHEST_DISPLAYABLE_DATE = new BigDate( "9999-12-31" );

    /**
     * earliest date we can handle
     */
    private static final BigDate LOWEST_DISPLAYABLE_DATE = new BigDate( "0001-01-01" );

    /**
     * The list of ChangeListeners for this model.  Subclasses may
     * store their own listeners here.
     */
    private final EventListenerList listenerList = new EventListenerList();

    /**
     * internal spinner for day of month
     */
    private final JSpinner ddSpinner;

    /**
     * internal spinner for month of year
     */
    private final JSpinner mmSpinner;

    /**
     * internal spinner for year
     */
    private final JSpinner yyyySpinner;

    /**
     * model to track selected day of month
     */
    private final SpinnerNumberModel ddModel;

    /**
     * model to track selected month of year
     */
    private final SpinnerNumberModel mmModel;

    /**
     * model to track year
     */
    private final SpinnerNumberModel yyyyModel;

    /**
     * biggest allowed date  to select
     */
    private BigDate maximum = HIGHEST_DISPLAYABLE_DATE;

    /**
     * lowest allowed date to select
     */
    private BigDate minimum = LOWEST_DISPLAYABLE_DATE;

    /**
     * current selected date value
     */
    private BigDate value = BigDate.localToday();

    /**
     * Only one ChangeEvent is needed per DateSpinner since the
     * event's only (read-only) state is the source property.  The source
     * of events generated here is always "this".
     */
    private transient ChangeEvent changeEvent = null;

    /**
     * month spinner was showing.
     */
    private int prevMM;

    /**
     * year spinner was showing.
     */
    private int prevYYYY;

    /**
     * day spinner now showing
     */
    private int selectedDD;

    /**
     * month  spinner now showing
     */
    private int selectedMM;

    /**
     * year spinner now showing.
     */
    private int selectedYYYY;

    /**
     * Constructor.
     */
    public DateSpinner()
        {
        setLayout( new FlowLayout( FlowLayout.LEFT, 1, 1 ) );
        yyyySpinner = new JSpinner();
        mmSpinner = new JSpinner();
        ddSpinner = new JSpinner();
        yyyyModel = new SpinnerNumberModel();
        yyyyModel.setStepSize( 1 );
        yyyyModel.setValue( this.value.getYYYY() );
        yyyySpinner.setModel( yyyyModel );
        yyyySpinner.setEditor( new LZNumberEditor( yyyySpinner, 4 ) );
        yyyySpinner.setName( "yyyySpinner" );
        mmModel = new SpinnerNumberModel();
        mmModel.setStepSize( 1 );
        mmModel.setValue( this.value.getMM() );
        mmSpinner.setModel( mmModel );
        mmSpinner.setEditor( new LZNumberEditor( mmSpinner, 2 ) );
        mmSpinner.setName( "mmSpinner" );
        ddModel = new SpinnerNumberModel();
        ddModel.setStepSize( 1 );
        ddModel.setValue( this.value.getDD() );
        ddSpinner.setModel( ddModel );
        ddSpinner.setEditor( new LZNumberEditor( ddSpinner, 2 ) );
        ddSpinner.setName( "ddSpinner" );
        // get values into the 3 inner spinners
        this.setValue( this.value );
        // pack three spinners left to right
        add( yyyySpinner );
        add( mmSpinner );
        add( ddSpinner );
        validate();
        }

    /**
     * one of yyyy mm or dd has changed. Tidy up the date and bounds and notify our clients.
     */
    void commonStateChanged()
        {
        // Assume caller has set up selectedYYY selectedMM and selectedDD
        // Assume caller has done odometer logic to corral date to something legal.
        if ( DEBUGGING )
            {
            out.println( "commonState change" );
            }
        // stop fibrillation
        yyyySpinner.removeChangeListener( this );
        mmSpinner.removeChangeListener( this );
        ddSpinner.removeChangeListener( this );
        // corral into app bounds.
        if ( BigDate.compare( selectedYYYY,
                selectedMM,
                selectedDD,
                minimum.getYYYY(),
                minimum.getMM(),
                minimum.getDD() ) < 0 )
            {
            selectedYYYY = minimum.getYYYY();
            selectedMM = minimum.getMM();
            selectedDD = minimum.getDD();
            }
        if ( BigDate.compare( selectedYYYY,
                selectedMM,
                selectedDD,
                maximum.getYYYY(),
                maximum.getMM(),
                maximum.getDD() ) > 0 )
            {
            selectedYYYY = maximum.getYYYY();
            selectedMM = maximum.getMM();
            selectedDD = maximum.getDD();
            }
        // set bounds on what user can key/spin
        final int yyyyMinimum = minimum.getYYYY();
        final int yyyyMaximum = maximum.getYYYY();
        final int mmMinimum = selectedYYYY == minimum.getYYYY()
                              ? minimum.getMM() : 0;
        final int mmMaximum = selectedYYYY == maximum.getYYYY()
                              ? maximum.getMM() :
                              13;
        final int ddMinimum = selectedYYYY == minimum.getYYYY() && selectedMM == minimum.getMM()
                              ? minimum.getDD() : 0;
        final int ddMaximum = selectedYYYY == maximum.getYYYY() && selectedMM == maximum.getMM()
                              ? maximum.getDD()
                              : BigDate.daysInMonth( selectedMM, selectedYYYY ) + 1;
        yyyyModel.setMinimum( yyyyMinimum );
        yyyyModel.setMaximum( yyyyMaximum );
        yyyyModel.setValue( selectedYYYY );
        mmModel.setMinimum( mmMinimum );
        mmModel.setMaximum( mmMaximum );
        mmModel.setValue( selectedMM );
        ddModel.setMinimum( ddMinimum );
        ddModel.setMaximum( ddMaximum );
        ddModel.setValue( selectedDD );
        value.set( selectedYYYY, selectedMM, selectedDD, BigDate.CHECK );
        prevYYYY = selectedYYYY;
        prevMM = selectedMM;
        // hook events from yyyy mm dd components back up again.
        yyyySpinner.addChangeListener( this );
        mmSpinner.addChangeListener( this );
        ddSpinner.addChangeListener( this );
        // even if no change since selectedYYYY, we still need to fire event
        fireStateChanged(); // notify our clients of the change.
        }

    /**
     * compose a tool tip based on the minimum and maximum bounds
     */
    void composeToolTip()
        {
        final FastCat sb = new FastCat( 5 );
        sb.append( "Enter a date between " );
        sb.append( minimum.toString() );
        sb.append( " and " );
        sb.append( maximum.toString() );
        sb.append( " by keying the year, then the month, then the date, or by using the spinners." );
        final String tip = sb.toString();
        yyyySpinner.setToolTipText( tip );
        mmSpinner.setToolTipText( tip );
        ddSpinner.setToolTipText( tip );
        }

    /**
     * Invoked when the JSpinner day changes, even one notch in
     * moving to another value
     */
    void ddStateChanged()
        {
        if ( DEBUGGING )
            {
            out.println( "ddSpinner change" );
            }
        selectedYYYY = yyyyModel.getNumber().intValue();
        selectedMM = mmModel.getNumber().intValue();
        selectedDD = ddModel.getNumber().intValue();
        // odometer logic.
        // adjust if day changed
        if ( selectedDD <= 0 )
            {
            selectedMM--;
            if ( selectedMM <= 0 )
                {
                selectedMM = 12;
                selectedYYYY--;
                }
            selectedDD = BigDate.daysInMonth( selectedMM, selectedYYYY );
            }
        else if ( selectedDD > BigDate.daysInMonth( selectedMM, selectedYYYY ) )
            {
            selectedDD = 1;
            selectedMM++;
            if ( selectedMM > 12 )
                {
                selectedMM = 1;
                selectedYYYY++;
                }
            }
        commonStateChanged();
        }

    /**
     * Run each ChangeListeners stateChanged() method.
     *
     * @see EventListenerList
     */
    private void fireStateChanged()
        {
        if ( DEBUGGING )
            {
            out.println( "firing" );
            }
        Object[] listeners = listenerList.getListenerList();
        for ( int i = listeners.length - 2; i >= 0; i -= 2 )
            {
            if ( listeners[ i ] == ChangeListener.class )
                {
                if ( changeEvent == null )
                    {
                    changeEvent = new ChangeEvent( this );
                    }
                ( ( ChangeListener ) listeners[ i + 1 ] ).stateChanged( changeEvent );
                }
            }
        }

    /**
     * Invoked when the JSpinner month changes, even one notch in
     * moving to another value
     */
    void mmStateChanged()
        {
        if ( DEBUGGING )
            {
            out.println( "mmSpinner change" );
            }
        selectedYYYY = yyyyModel.getNumber().intValue();
        selectedMM = mmModel.getNumber().intValue();
        selectedDD = ddModel.getNumber().intValue();
        // odometer logic.
        // adjust if month changed
        if ( selectedMM <= 0 )
            {
            selectedYYYY--;
            selectedMM = 12;
            selectedDD = 31;
            }
        else if ( selectedMM > 12 )
            {
            selectedYYYY++;
            selectedMM = 1;
            selectedDD = 1;
            }
        else if ( selectedMM > prevMM )
            {
            selectedDD = 1;
            }
        else if ( selectedMM < prevMM )
            {
            selectedDD = BigDate.daysInMonth( selectedMM, selectedYYYY );
            }
        commonStateChanged();
        }

    /**
     * Invoked when the JSpinner year changes, even one notch in
     * moving to another value
     */
    void yyyyStateChanged()
        {
        if ( DEBUGGING )
            {
            out.println( "yyyySpinner change" );
            }
        selectedYYYY = yyyyModel.getNumber().intValue();
        selectedMM = mmModel.getNumber().intValue();
        selectedDD = ddModel.getNumber().intValue();
        if ( selectedYYYY > prevYYYY )
            {
            selectedMM = 1;
            selectedDD = 1;
            }
        else if ( selectedYYYY < prevYYYY )
            {
            selectedMM = 12;
            selectedDD = 31;
            }
        commonStateChanged();
        }

    /**
     * Adds a listener to the list that is notified each time a change
     * to the DateSpinner value occurs.  The source of <code>ChangeEvents</code>
     * delivered to <code>ChangeListeners</code> will be this
     * <code>DateSpinner</code>.
     *
     * @param listener the <code>ChangeListener</code> to add
     */
    public void addChangeListener( ChangeListener listener )
        {
        listenerList.add( ChangeListener.class, listener );
        }

    /**
     * Get the highest allowable date selection
     *
     * @return maximum allowable BigDate
     */
    public BigDate getMaximum()
        {
        return ( BigDate ) maximum.clone();
        }

    /**
     * set the highest allowable date selection. Initially 9999-12-31.
     *
     * @param maximum as a BigDate with 4-digit positive year.
     */
    public void setMaximum( BigDate maximum )
        {
        if ( DEBUGGING )
            {
            out.println( "max change" );
            }
        assert LOWEST_DISPLAYABLE_DATE.compareTo( maximum ) <= 0 && maximum.compareTo( HIGHEST_DISPLAYABLE_DATE ) <=
                                                                    0 : "DateSpinner.maximum out of range";
        this.maximum = ( BigDate ) maximum.clone(); // clone in case user later changes.
        commonStateChanged(); // corral date into new bounds
        composeToolTip();
        }

    /**
     * Get the lowest allowable date selection
     *
     * @return minimum allowable BigDate
     */
    public BigDate getMinimum()
        {
        return ( BigDate ) minimum.clone();
        }

    /**
     * set the lowest allowable date selection. Initially 0001-01-01.
     *
     * @param minimum as a BigDate with 4-digit positive year.
     */
    public void setMinimum( BigDate minimum )
        {
        if ( DEBUGGING )
            {
            out.println( "min change" );
            }
        assert LOWEST_DISPLAYABLE_DATE.compareTo( minimum ) <= 0 && minimum.compareTo( HIGHEST_DISPLAYABLE_DATE ) <=
                                                                    0 : "DateSpinner.minimum out of range";
        this.minimum = ( BigDate ) minimum.clone(); // clone in case user later changes.
        commonStateChanged(); // corral date into new bounds
        composeToolTip();
        }

    /**
     * Get the current date selection
     *
     * @return current selected date as a BigDate
     */
    public BigDate getValue()
        {
        // value is kept up to data as 3 internal JSpinners change.
        return ( BigDate ) value.clone(); // don't let caller fiddle with our object.
        }

    /**
     * set the current data selection. Initially today's date.
     *
     * @param value as a BigDate with 4-digit positive year.
     */
    @SuppressWarnings( { "WeakerAccess" } )
    public void setValue( BigDate value )
        {
        if ( DEBUGGING )
            {
            out.println( "value change" );
            }
        this.value = ( BigDate ) value.clone(); // will be modified, Don't wreck caller's object
        selectedYYYY = value.getYYYY();
        selectedMM = value.getMM();
        selectedDD = value.getDD();
        commonStateChanged();
        }

    /**
     * Removes a ChangeListener from the DateSpinners listener list.
     *
     * @param listener the ChangeListener to remove
     *
     * @see #addChangeListener
     * @see javax.swing.SpinnerModel#removeChangeListener
     */
    public void removeChangeListener( ChangeListener listener )
        {
        listenerList.remove( ChangeListener.class, listener );
        }

    /**
     * Enable or disable the spinner
     *
     * @param enabled true to enable the DateSpinner
     */
    public void setEnabled( boolean enabled )
        {
        yyyySpinner.setEnabled( enabled );
        mmSpinner.setEnabled( enabled );
        ddSpinner.setEnabled( enabled );
        }

    /**
     * fields events from all three yyyy mm dd components
     *
     * @param e ChangeEvent, which component triggered event.
     */
    public void stateChanged( ChangeEvent e )
        {
        Object source = e.getSource();
        if ( source.equals( yyyySpinner ) )
            {
            yyyyStateChanged();
            }
        else if ( source.equals( mmSpinner ) )
            {
            mmStateChanged();
            }
        else if ( source.equals( ddSpinner ) )
            {
            ddStateChanged();
            }
        else
            {
            throw new IllegalArgumentException( "DataSpinner Bug: Change event from unexpected source." + source );
            }
        }
    }