package com.onaro.util.jfc.collapsible;

import java.awt.Cursor;
import java.net.URL;
import java.util.ResourceBundle;

import javax.swing.Action;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

/**
 * A button who's text behaves like a hyperlink. Note that if the arrow is too narrow for the text,
 * it will be wrapped into multiple lines.
 * <p>
 *
 * <p>
 * Implemented by wrapping the text within HTML tags. The hyperlink effect is achieved by using the A tag.
 */
public class HyperlinkButton extends JButton {

    private static final long serialVersionUID = 1L;

    /**
     * HTML document which is used when the mouse isn't over the button. HTML is used to enable the text wrapping
     * that is done by the HTML of the rollover text.
     */
    private String plainText;

    /**
     * HTML document which is used when the mouse is over the button. This HTML is using the A tag to create the
     * hyperlink effect.
     */
    private String rolloverText;
    
    private boolean displayLinkAlways = false;

    /**
     * Helps preventing the text from flickering when the button changes from "normal" to "rollover" and the opposite.
     * Used to ignore calls to {@link HyperlinkButton#repaint()} and {@link HyperlinkButton#invalidate()} which are
     * invoked by {@link JButton#setText(String)}.
     */
    private boolean textIsChanging = false;

    private final static Logger logger = LogManager.getLogger(HyperlinkButton.class);

    /**
     * Constructs a button with text and a single icon that will be used for normal, mouse-over and pressed modes.
     * Icons are resources and are searched for in the classpath, see {@link Class#getResource(String)}.
     * @param text button label
     * @param icon icon file-name for the normal, mouse-over and pressed modes
     */
    public HyperlinkButton(String text, String icon) {
        this(text, getIcon(null, icon), null, null);
    }

    /**
     * Constructs a button with text and a single icon that will be used for normal, mouse-over and pressed modes.
     * Icons are resources and are searched for in the classpath, see {@link Class#getResource(String)}.
     * @param text button label
     * @param prefix when attached to the <code>icon</code>, it provides the icon file-name, may be null
     * @param icon icon file-name
     */
    public HyperlinkButton(String text, String prefix, String icon) {
        this(text, getIcon(prefix, icon), null, null);
    }

    /**
     * Constructs a button with text and different icons for normal, mouse-over and pressed modes.
     * Icons are resources and are searched for in the classpath, see {@link Class#getResource(String)}.
     * @param text button label
     * @param prefix when attached to of the icons, provides the icon file-name, may be null
     * @param icon normal mode icon
     * @param rollover mouse-over icon
     * @param pressed button-pressed icon
     */
    public HyperlinkButton(String text, String prefix, String icon, String rollover, String pressed) {
        this(text, getIcon(prefix, icon), getIcon(prefix, rollover), getIcon(prefix, pressed));
    }

    /**
     * Constructs a button with text and different icons for normal, mouse-over and pressed modes.
     * @param text button label
     * @param icon normal mode icon
     * @param rollover mouse-over icon
     * @param pressed button-pressed icon
     */
    public HyperlinkButton(String text, Icon icon, Icon rollover, Icon pressed) {
        super(text, icon);
        init();
        if (rollover != null) setRolloverIcon(rollover);
        if (pressed != null) setPressedIcon(pressed);
    }

    /**
     * Constructs a button with text and different icons for normal, mouse-over and pressed modes.
     *
     * @param action to be performed when the button is clicked
     */
    public HyperlinkButton(Action action){
        super(action);
        init();
    }

    private void init() {
        setHorizontalAlignment(JButton.LEFT);
        setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
        setContentAreaFilled(false);
        setBorderPainted(false);
        setFocusPainted(false);
        setBorder(null);
        setIconTextGap(2);

        registerTextChange();
    }

    /**
     * Changes the button's text according to its rollover state (mouse over).
     */
    protected void registerTextChange() {
        getModel().addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent e) {
            	if (displayLinkAlways) {
            		return;
            	}
                if (getModel().isRollover())
                    setShownText(rolloverText);
                else
                    setShownText(plainText);
            }
        });
    }

    /**
     * Avoids the text from filckering when the button changes from "normal" to "rollover" and the oposite by ignoring
     * calls which are invoked by {@link JButton#setText(String)}.
     */
    public void revalidate() {
        if (!textIsChanging) super.revalidate();
    }

    /**
     * Avoids the text from filckering when the button changes from "normal" to "rollover" and the oposite by ignoring
     * calls which are invoked by {@link JButton#setText(String)}.
     */
    public void repaint() {
        if (!textIsChanging) super.repaint();
    }

    /**
     * Sets the text currently shown by the button. This text changes when the mouse rolls over the button
     * @param text the string to display
     */
    protected void setShownText(String text){
        textIsChanging = true;
        super.setText(text);
        textIsChanging = false;
    }

    /**
     * Sets the button's text label. Consructs the HTML documents providing the hyperlink and text-wrapp effects.
     * @param text the label
     */
    public void setText(String text) {
        plainText = Messages.INSTANCE.getPlainText(text);
        rolloverText = toLink(text, false);
        setShownText(plainText);
    }

    public String toLink(String text, boolean bold) {
      return bold ? Messages.INSTANCE.getHRefBoldText(text): Messages.INSTANCE.getHRefNoBoldText(text);
    }

    public boolean isDisplayLinkAlways() {
		return displayLinkAlways;
	}

	public void setDisplayLinkAlways(boolean displayLinkAlways) {
		this.displayLinkAlways = displayLinkAlways;
		if (displayLinkAlways) {
			setShownText(rolloverText);
		} else {
			setShownText(plainText);
		}
	}

	/**
     * Gets an icon-file-name string from a resource-file where the key is the concatenation of the prefix and the suffix.
     * @param resources a resource file from which to fetch the string
     * @param prefix key prefix
     * @param suffix key suffix
     * @return the string from the resource file or null if no such resource was found
     */
    public static String getIconFileName(ResourceBundle resources, String prefix, String suffix) {
        try {
            return resources.getString(prefix + suffix);
        } catch (Exception e) {
            return null; // No icon was specified
        }
    }

    /**
     * A utility for fetching an icon from the classpath.
     * @param prefix resource-name prefix
     * @param name resource-name suffix
     * @return the icon or null if the icon was found
     */
    private static Icon getIcon(String prefix, String name) {
        if (name == null) return null;
        String iconName = prefix != null ? prefix + name : name;
        URL resource = HyperlinkButton.class.getResource(iconName);
        if (resource == null) {
            logger.error("Failed to find icon named: " + iconName, new IllegalArgumentException("Failed to find icon: prefix='" + prefix + "' ; name='" + name + '\'')); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
            return null;
        }
        else
            return new ImageIcon(resource);
    }

}