/*
 * @(#)DefaultSynthStyleFactory.java	1.6 03/12/19
 *
 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
package javax.swing.plaf.synth;

import javax.swing.*;
import javax.swing.plaf.FontUIResource;
import java.awt.Font;
import java.util.*;
import java.util.regex.*;
import sun.swing.plaf.synth.*;
import sun.swing.BakedArrayList;

/**
 * Factory used for obtaining styles. Supports associating a style based on
 * the name of the component as returned by <code>Component.getName()</code>,
 * and the <code>Region</code> associated with the <code>JComponent</code>.
 * Lookup is done using regular expressions.
 *
 * @version 1.6, 12/19/03
 * @author Scott Violet
 */
class DefaultSynthStyleFactory extends SynthStyleFactory {
    /**
     * Used to indicate the lookup should be done based on Component name.
     */
    public static final int NAME = 0;
    /**
     * Used to indicate the lookup should be done based on region.
     */
    public static final int REGION = 1;

    /**
     * List containing set of StyleAssociations that are to match based on
     * Component name.
     */
    private List _nameStyles;
    /**
     * List containing set of StyleAssociations that are to match based on
     * Region.
     */
    private List _regionStyles;
    /**
     * Used during lookup.
     */
    private BakedArrayList _tmpList;

    /**
     * Maps from a List (BakedArrayList to be precise) to the merged style.
     */
    private Map _resolvedStyles;

    /**
     * Used if there are no styles matching a widget.
     */
    private SynthStyle _defaultStyle;


    DefaultSynthStyleFactory() {
        _tmpList = new BakedArrayList(5);
        _resolvedStyles = new HashMap();
    }

    public synchronized void addStyle(DefaultSynthStyle style,
                         String path, int type) throws PatternSyntaxException {
        if (path == null) {
            // Make an empty path match all.
            path = ".*";
        }
        if (type == NAME) {
            if (_nameStyles == null) {
                _nameStyles = new ArrayList();
            }
            _nameStyles.add(StyleAssociation.createStyleAssociation(
                                path, style));
        }
        else if (type == REGION) {
            if (_regionStyles == null) {
                _regionStyles = new ArrayList();
            }
            _regionStyles.add(StyleAssociation.createStyleAssociation(
                                path.toLowerCase(), style));
        }
    }

    /**
     * Returns the style for the specified Component.
     *
     * @param c Component asking for
     * @param id ID of the Component
     */
    public synchronized SynthStyle getStyle(JComponent c, Region id) {
        BakedArrayList matches = _tmpList;

        matches.clear();
        getMatchingStyles(matches, c, id);

        if (matches.size() == 0) {
            return getDefaultStyle();
        }
        // Use a cached Style if possible, otherwise create a new one.
        matches.cacheHashCode();
        SynthStyle style = getCachedStyle(matches);

        if (style == null) {
            style = mergeStyles(matches);

            if (style != null) {
                cacheStyle(matches, style);
            }
        }
        return style;
    }

    /**
     * Returns the style to use if there are no matching styles.
     */
    private SynthStyle getDefaultStyle() {
        if (_defaultStyle == null) {
            _defaultStyle = new DefaultSynthStyle();
            ((DefaultSynthStyle)_defaultStyle).setFont(
                new FontUIResource("Dialog", Font.PLAIN,12));
        }
        return _defaultStyle;
    }

    /**
     * Fetches any styles that match the passed into arguments into
     * <code>matches</code>.
     */
    private void getMatchingStyles(java.util.List matches, JComponent c,
                                   Region id) {
        // First match on REGION
        if (_regionStyles != null) {
            getMatches(id.getLowerCaseName(), _regionStyles, matches);
        }
        // Then match on name
        if (_nameStyles != null) {
            String name = c.getName();

            if (name == null) {
                name = "";
            }
            getMatches(name, _nameStyles, matches);
        }
    }

    private void getMatches(CharSequence path, java.util.List styles,
                            java.util.List matches) {
        for (int counter = styles.size() - 1; counter >= 0; counter--){
            StyleAssociation sa = (StyleAssociation)styles.get(counter);

            if (sa.matches(path) && matches.indexOf(sa.getStyle()) == -1) {
                matches.add(sa.getStyle());
            }
        }
    }

    /**
     * Caches the specified style.
     */
    private void cacheStyle(java.util.List styles, SynthStyle style) {
        BakedArrayList cachedStyles = new BakedArrayList(styles);

        _resolvedStyles.put(cachedStyles, style);
    }

    /**
     * Returns the cached style from the passed in arguments.
     */
    private SynthStyle getCachedStyle(java.util.List styles) {
        if (styles.size() == 0) {
            return null;
        }
        return (SynthStyle)_resolvedStyles.get(styles);
    }

    /**
     * Creates a single Style from the passed in styles. The passed in List
     * is reverse sorted, that is the most recently added style found to
     * match will be first.
     */
    private SynthStyle mergeStyles(java.util.List styles) {
        int size = styles.size();

        if (size == 0) {
            return null;
        }
        else if (size == 1) {
            return (SynthStyle)((DefaultSynthStyle)styles.get(0)).clone();
        }
        // NOTE: merging is done backwards as DefaultSynthStyleFactory reverses
        // order, that is, the most specific style is first.
        DefaultSynthStyle style = (DefaultSynthStyle)styles.get(size - 1);

        style = (DefaultSynthStyle)style.clone();
        for (int counter = size - 2; counter >= 0; counter--) {
            style = ((DefaultSynthStyle)styles.get(counter)).addTo(style);
        }
        return style;
    }
}