package jmri.jmrit.throttle.panels;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.io.File;
import java.util.ArrayList;

import javax.annotation.CheckForNull;
import javax.annotation.Nonnull;
import javax.swing.*;

import jmri.InstanceManager;
import jmri.Throttle;
import jmri.jmrit.throttle.interfaces.FunctionListener;
import jmri.jmrit.throttle.preferences.ThrottlesPreferences;
import jmri.util.FileUtil;
import jmri.util.swing.JmriMouseAdapter;
import jmri.util.swing.JmriMouseEvent;
import jmri.util.swing.JmriMouseListener;
import jmri.util.swing.ResizableImagePanel;
import jmri.util.com.sun.ToggleOrPressButtonModel;
import jmri.util.gui.GuiLafPreferencesManager;

import org.jdom2.Element;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * A JButton to activate functions on the decoder. FunctionButtons have a
 right-click popupMenu menu with several configuration options:
 <ul>
 * <li> Set the text
 * <li> Set the locking state
 * <li> Set visibility
 * <li> Set Font
 * <li> Set function number identity
 * </ul>
 * 
 * <hr>
 * This file is part of JMRI.
 * <p>
 * JMRI is free software; you can redistribute it and/or modify it under the
 * terms of version 2 of the GNU General Public License as published by the Free
 * Software Foundation. See the "COPYING" file for a copy of this license.
 * <p>
 * JMRI is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 * A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * @author Glen Oberhauser
 * @author Bob Jacobsen Copyright 2008
 * @author Lionel Jeanson 2021
 */
public class FunctionButton extends JToggleButton {

    private final ArrayList<FunctionListener> listeners;
    private int identity; // F0, F1, etc
    private boolean isDisplayed = true;
    private boolean dirty = false;
    private boolean isImageOK = false;
    private boolean isSelectedImageOK = false;
    private String buttonLabel;
    private JPopupMenu popupMenu;
    private FunctionButtonPropertyEditor editor ;
    private String iconPath;
    private String selectedIconPath;
    private String dropFolder;
    private ToggleOrPressButtonModel _model;
    private Throttle _throttle;
    private int img_size = DEFAULT_IMG_SIZE;
    private static final int BUT_HGHT = 24;
    private static final int BUT_MAX_WDTH = 256;
    private static final int BUT_MIN_WDTH = 100;

    public static final int DEFAULT_IMG_SIZE = 48;

    public void destroy() {        
        if (editor != null) {
            editor.destroy();
        }
        _throttle = null;
    }
    
    /**
     * Get Button Height.
     * @return height.
     */
    public static int getButtonHeight() {
        return BUT_HGHT;
    }

    /**
     * Get the Button Width.
     * @return width.
     */
    public static int getButtonWidth() {
        return BUT_MIN_WDTH;
    }

    /**
     * Get the Image Button Width.
     * @return width.
     */
    public int getButtonImageSize() {
        return img_size;
    }

    /**
     * Set the Image Button Hieght and Width.
     * @param is the image size (sqaure image size = width = height)
     */
    public void setButtonImageSize(int is) {
        img_size = is;
    }

    /**
     * Construct the FunctionButton.
     * 
     * @param withPopupMenu  popup menu on function button available if true
     */
    public FunctionButton(boolean withPopupMenu) {
        super();
        listeners = new ArrayList<>();
        initGUI(withPopupMenu);
    }

    public FunctionButton() {
        this(true);
    }

    private void initGUI(boolean withPopupMenu){
        _model = new ToggleOrPressButtonModel(this, true);
        setModel(_model);
        //Add listener to components that can bring up popupMenu menus.
        if (withPopupMenu) {
            addMouseListener(JmriMouseListener.adapt(new PopupListener()));
        }
        setFont(new Font("Monospaced", Font.PLAIN, InstanceManager.getDefault(GuiLafPreferencesManager.class).getFontSize()));
        setMargin(new Insets(2, 2, 2, 2));
        setRolloverEnabled(false);
        updateLnF();
    }

    /**
     * Set the function number this button will operate.
     *
     * @param id An integer, minimum 0.
     */
    public void setIdentity(int id) {
        this.identity = id;
    }

    /**
     * Get the function number this button operates.
     *
     * @return An integer, minimum 0.
     */
    public int getIdentity() {
        return identity;
    }

    /**
     * Set the state of the function button.
     * Does not send update to layout, just updates button status.
     * <p>
     * To update AND send to layout use setSelected(boolean).
     *
     * @param isOn True if the function should be active.
     */
    public void setState(boolean isOn) {
        super.setSelected(isOn);
        _model.updateSelected(isOn);
    }

    /**
     * Get the state of the function.
     *
     * @return true if the function is active.
     */
    public boolean getState() {
        return isSelected();
    }

    /**
     * Set the locking state of the button.
     * <p>
     * Changes in this parameter are only be sent to the
     * listeners if the dirty bit is set.
     *
     * @param isLockable True if the a clicking and releasing the button changes
     *                   the function state. False if the state is changed back
     *                   when the button is released
     */
    public void setIsLockable(boolean isLockable) {
        _model.setLockable(isLockable);
        if (isDirty()) {
            for (int i = 0; i < listeners.size(); i++) {
                listeners.get(i).notifyFunctionLockableChanged(identity, isLockable);
            }
        }
    }

    /**
     * Get the locking state of the function.
     *
     * @return True if the a clicking and releasing the button changes the
     *         function state. False if the state is changed back when 
     *         button is released
     */
    public boolean getIsLockable() {
        return _model.getLockable();
    }

    /**
     * Set the display state of the button.
     *
     * @param displayed True if the button exists False if the button has been
     *                  removed by the user
     */
    public void setDisplay(boolean displayed) {
        this.isDisplayed = displayed;
    }

    /**
     * Get the display state of the button.
     *
     * @return True if the button exists False if the button has been removed by
     *         the user
     */
    public boolean getDisplay() {
        return isDisplayed;
    }

    /**
     * Set Function Button Dirty.
     *
     * @param dirty True when button has been modified by user, else false.
     */
    public void setDirty(boolean dirty) {
        this.dirty = dirty;
    }

    /**
     * Get if Button is Dirty.
     * @return true when function button has been modified by user.
     */
    public boolean isDirty() {
        return dirty;
    }

    /**
     * Get the Button Label.
     * @return Button Label text.
     */
    public String getButtonLabel() {
        return buttonLabel;
    }

    /**
     * Set the Button Label.
     * @param label Label Text.
     */
    public void setButtonLabel(String label) {
        buttonLabel = label;
    }

    /**
     * Set Button Text.
     * {@inheritDoc}
     */
    @Override
    public void setText(String s) {
        if (s != null) {
            buttonLabel = s;
            if (isImageOK) {
                setToolTipText(buttonLabel);
                super.setText(null);
            } else {
                super.setText(s);
            }
            return;
        }
        super.setText(null);
        if (buttonLabel != null) {
            setToolTipText(buttonLabel);
        }
    }

    /**
     * Update Button Look and Feel :
     *    Hide/show it if necessary
     *    Decide if it should show the label or an image with text as tooltip.
     *    Button UI updated according to above result.
     */
    public void updateLnF() {
        setFocusable(false); // for throttle window keyboard controls
        setVisible(isDisplayed);
        setBorderPainted(!isImageOK());
        setContentAreaFilled(!isImageOK());
        if (isImageOK()) { // adjust button for image
            setText(null);
            setMinimumSize(new Dimension(img_size, img_size));
            setMaximumSize(new Dimension(img_size, img_size));
            setPreferredSize(new Dimension(img_size, img_size));
        }
        else { // adjust button for text
            setText(getButtonLabel());
            setMinimumSize(new Dimension(FunctionButton.BUT_MIN_WDTH, FunctionButton.BUT_HGHT));
            setMaximumSize(new Dimension(FunctionButton.BUT_MAX_WDTH, FunctionButton.BUT_HGHT));
            if (getButtonLabel() != null) {
                int butWidth = getFontMetrics(getFont()).stringWidth(getButtonLabel()) + 64; // pad out the width a bit
                butWidth = Math.min(butWidth, FunctionButton.BUT_MAX_WDTH );
                butWidth = Math.max(butWidth, FunctionButton.BUT_MIN_WDTH );
                setPreferredSize(new Dimension( butWidth, FunctionButton.BUT_HGHT));
            } else {
                setPreferredSize(new Dimension(BUT_MIN_WDTH, BUT_HGHT));
            }
        }
    }

    /**
     * Change the state of the function.
     * Sets internal state, setSelected, and sends to listeners.
     * <p>
     * To update this button WITHOUT sending to layout, use setState.
     *
     * @param newState true = Is Function on, False = Is Function off.
     */
    @Override
    public void setSelected(boolean newState){
        log.debug("function selected {}", newState);
        super.setSelected(newState);
        for (int i = 0; i < listeners.size(); i++) {
            listeners.get(i).notifyFunctionStateChanged(identity, newState);
        }
    }

    /**
     * Add a listener to this button, probably some sort of keypad panel.
     *
     * @param l The FunctionListener that wants notifications via the
     *          FunctionListener.notifyFunctionStateChanged.
     */
    public void addFunctionListener(FunctionListener l) {
        if (!listeners.contains(l)) {
            listeners.add(l);
        }
    }

    /**
     * Remove a listener from this button.
     *
     * @param l The FunctionListener to be removed
     */
    public void removeFunctionListener(FunctionListener l) {
        listeners.remove(l);
    }

    /**
     * Set the folder where droped images in function button property panel will be stored
     *
     * @param df the folder path
     */
    void setDropFolder(String df) {
        dropFolder = df;
    }

    /**
     * A PopupListener to handle mouse clicks and releases.
     * Handles the popupMenu menu.
     */
    private class PopupListener extends JmriMouseAdapter {

        /**
         * If the event is the popupMenu trigger, which is dependent on the platform, present the popupMenu menu.
         * @param e The MouseEvent causing the action.
         */
        @Override
        public void mouseClicked(JmriMouseEvent e) {
            checkTrigger(e);
        }

        /**
         * If the event is the popupMenu trigger, which is dependent on the platform, present the popupMenu menu.
         * @param e The MouseEvent causing the action.
         */
        @Override
        public void mousePressed(JmriMouseEvent e) {
            checkTrigger( e);
        }

        /**
         * If the event is the popupMenu trigger, which is dependent on the  platform, present the popupMenu menu.
         * @param e The MouseEvent causing the action.
         */
        @Override
        public void mouseReleased(JmriMouseEvent e) {
            checkTrigger( e);
        }

        private void checkTrigger( JmriMouseEvent e) {
            if (e.isPopupTrigger() && e.getComponent().isEnabled() ) {
                initPopupMenu();
                popupMenu.show(e.getComponent(), e.getX(), e.getY());
            }
        }
    }

    private void initPopupMenu() {
        if (popupMenu == null) {
            JMenuItem propertiesItem = new JMenuItem(Bundle.getMessage("MenuItemProperties"));
            propertiesItem.addActionListener((ActionEvent e) -> {
                if (editor == null) {
                    editor = new FunctionButtonPropertyEditor(this);
                }
                editor.resetProperties();
                editor.setLocation(MouseInfo.getPointerInfo().getLocation());
                editor.setVisible(true);
                editor.setDropFolder(dropFolder);
            });
            popupMenu = new JPopupMenu();
            popupMenu.add(propertiesItem);
        }
    }

    /**
     * Collect the prefs of this object into XML Element.
     * <ul>
     * <li> identity
     * <li> text
     * <li> isLockable
     * </ul>
     *
     * @return the XML of this object.
     */
    public Element getXml() {
        Element me = new Element("FunctionButton"); // NOI18N
        me.setAttribute("id", String.valueOf(this.getIdentity()));
        me.setAttribute("text", this.getButtonLabel());
        me.setAttribute("isLockable", String.valueOf(this.getIsLockable()));
        me.setAttribute("isVisible", String.valueOf(this.getDisplay()));
        if (getFont().getSize() != InstanceManager.getDefault(GuiLafPreferencesManager.class).getFontSize()) {
            me.setAttribute("fontSize", String.valueOf(this.getFont().getSize()));
        }
        me.setAttribute("buttonImageSize", String.valueOf(this.getButtonImageSize()));
        if (this.getIconPath().startsWith(FileUtil.getUserResourcePath())) {
            me.setAttribute("iconPath", this.getIconPath().substring(FileUtil.getUserResourcePath().length()));
        } else {
            me.setAttribute("iconPath", this.getIconPath());
        }
        if (this.getSelectedIconPath().startsWith(FileUtil.getUserResourcePath())) {
            me.setAttribute("selectedIconPath", this.getSelectedIconPath().substring(FileUtil.getUserResourcePath().length()));
        } else {
            me.setAttribute("selectedIconPath", this.getSelectedIconPath());
        }
        return me;
    }

    /**
     * Check if File exists.
     * @param name File name
     * @return true if exists, else false.
     */
    private boolean checkFile(String name) {
        File fp = new File(name);
        return fp.exists();
    }

    /**
     * Set the preferences based on the XML Element.
     * <ul>
     * <li> identity
     * <li> text
     * <li> isLockable
     * </ul>
     *
     * @param e The Element for this object.
     */
    public void setXml(Element e) {
        final ThrottlesPreferences preferences = InstanceManager.getDefault(ThrottlesPreferences.class); 
        try {
            this.setIdentity(e.getAttribute("id").getIntValue());
            this.setText(e.getAttribute("text").getValue());
            this.setIsLockable(e.getAttribute("isLockable").getBooleanValue());
            this.setDisplay(e.getAttribute("isVisible").getBooleanValue());
            if (e.getAttribute("fontSize") != null) {
                this.setFont(new Font("Monospaced", Font.PLAIN, e.getAttribute("fontSize").getIntValue()));
            } else {
                this.setFont(new Font("Monospaced", Font.PLAIN, InstanceManager.getDefault(GuiLafPreferencesManager.class).getFontSize()));
            }
            this.setButtonImageSize( (e.getAttribute("buttonImageSize")!=null)?e.getAttribute("buttonImageSize").getIntValue():DEFAULT_IMG_SIZE);
            if (preferences.isUsingExThrottle() && preferences.isUsingFunctionIcon() && (e.getAttribute("iconPath") != null) && (e.getAttribute("iconPath").getValue().length() > 0)) {
                if (checkFile(FileUtil.getUserResourcePath() + e.getAttribute("iconPath").getValue())) {
                    this.setIconPath(FileUtil.getUserResourcePath() + e.getAttribute("iconPath").getValue());
                } else {
                    this.setIconPath(e.getAttribute("iconPath").getValue());
                }
            } else {
                this.setIconPath(null);
            }
            if ((e.getAttribute("selectedIconPath") != null) && (e.getAttribute("selectedIconPath").getValue().length() > 0)) {
                if (checkFile(FileUtil.getUserResourcePath() + e.getAttribute("selectedIconPath").getValue())) {
                    this.setSelectedIconPath(FileUtil.getUserResourcePath() + e.getAttribute("selectedIconPath").getValue());
                } else {
                    this.setSelectedIconPath(e.getAttribute("selectedIconPath").getValue());
                }
            } else {
                this.setSelectedIconPath(null);
            }
            updateLnF();
        } catch (org.jdom2.DataConversionException ex) {
            log.error("DataConverstionException in setXml", ex);
        }
    }

    /**
     * Set the Icon Path, NON selected.
     * <p>
     * Checks image and sets isImageOK flag.
     * @param fnImg icon path.
     */
    public void setIconPath(String fnImg) {
        iconPath = fnImg;
        ResizableImagePanel fnImage = new ResizableImagePanel();
        fnImage.setBackground(new Color(0, 0, 0, 0));
        fnImage.setRespectAspectRatio(true);
        fnImage.setSize(new Dimension(img_size,img_size));
        fnImage.setImagePath(fnImg);
        if (fnImage.getScaledImage() != null) {
            setIcon(new ImageIcon(fnImage.getScaledImage()));
            isImageOK = true;
        } else {
            setIcon(null);
            isImageOK = false;
        }
    }

    /**
     * Get the Icon Path, NON selected.
     * @return Icon Path, else empty string if null.
     */
    @Nonnull
    public String getIconPath() {
        if (iconPath == null) {
            return "";
        }
        return iconPath;
    }

    /**
     * Set the Selected Icon Path.
     * <p>
     * Checks image and sets isSelectedImageOK flag.
     * @param fnImg selected icon path.
     */
    public void setSelectedIconPath(String fnImg) {
        selectedIconPath = fnImg;
        ResizableImagePanel fnSelectedImage = new ResizableImagePanel();
        fnSelectedImage.setBackground(new Color(0, 0, 0, 0));
        fnSelectedImage.setRespectAspectRatio(true);
        fnSelectedImage.setSize(new Dimension(img_size, img_size));
        fnSelectedImage.setImagePath(fnImg);
        if (fnSelectedImage.getScaledImage() != null) {
            ImageIcon icon = new ImageIcon(fnSelectedImage.getScaledImage());
            setSelectedIcon(icon);
            setPressedIcon(icon);
            isSelectedImageOK = true;
        } else {
            setSelectedIcon(null);
            setPressedIcon(null);
            isSelectedImageOK = false;
        }
    }

    /**
     * Get the Selected Icon Path.
     * @return selected Icon Path, else empty string if null.
     */
    @Nonnull
    public String getSelectedIconPath() {
        if (selectedIconPath == null) {
            return "";
        }
        return selectedIconPath;
    }

    /**
     * Get if isImageOK.
     * @return true if isImageOK.
     */
    public boolean isImageOK() {
        return isImageOK;
    }

    /**
     * Get if isSelectedImageOK.
     * @return true if isSelectedImageOK.
     */
    public boolean isSelectedImageOK() {
        return isSelectedImageOK;
    }

    /**
     * Set Throttle.
     * @param throttle the throttle that this button is associated with.
     */
    protected void setThrottle( Throttle throttle) {
        _throttle = throttle;
    }

    /**
     * Get Throttle for this button.
     * @return throttle associated with this button.  May be null if no throttle currently associated.
     */
    @CheckForNull
    protected Throttle getThrottle() {
        return _throttle;
    }

    private static final Logger log = LoggerFactory.getLogger(FunctionButton.class);

}