package org.apache.commons.digester3;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.xml.sax.Attributes;


Default implementation of the Rules interface that supports the standard rule matching behavior. This
class can also be used as a base class for specialized Rules implementations.


The matching policies implemented by this class support two different types of pattern matching rules:


Exact Match - A pattern "a/b/c" exactly matches a <c> element, nested inside a
<b> element, which is nested inside an <a> element.
Tail Match - A pattern "*/a/b" matches a <b> element, nested inside an
<a> element, no matter how deeply the pair is nested.


Note that wildcard patterns are ignored if an explicit match can be found (and when multiple wildcard patterns match,
only the longest, ie most explicit, pattern is considered a match).


See the package documentation for package org.apache.commons.digester3 for more information.

/**
 * <p>
 * Default implementation of the <code>Rules</code> interface that supports the standard rule matching behavior. This
 * class can also be used as a base class for specialized <code>Rules</code> implementations.
 * </p>
 * <p>
 * The matching policies implemented by this class support two different types of pattern matching rules:
 * </p>
 * <ul>
 * <li><em>Exact Match</em> - A pattern "a/b/c" exactly matches a <code>&lt;c&gt;</code> element, nested inside a
 * <code>&lt;b&gt;</code> element, which is nested inside an <code>&lt;a&gt;</code> element.</li>
 * <li><em>Tail Match</em> - A pattern "&#42;/a/b" matches a <code>&lt;b&gt;</code> element, nested inside an
 * <code>&lt;a&gt;</code> element, no matter how deeply the pair is nested.</li>
 * </ul>
 * <p>
 * Note that wildcard patterns are ignored if an explicit match can be found (and when multiple wildcard patterns match,
 * only the longest, ie most explicit, pattern is considered a match).
 * </p>
 * <p>
 * See the package documentation for package org.apache.commons.digester3 for more information.
 * </p>
 */

public class RulesBase
    extends AbstractRulesImpl
{

    // ----------------------------------------------------- Instance Variables

    
The set of registered Rule instances, keyed by the matching pattern. Each value is a List containing the Rules
for that pattern, in the order that they were orginally registered.
/**
     * The set of registered Rule instances, keyed by the matching pattern. Each value is a List containing the Rules
     * for that pattern, in the order that they were orginally registered.
     */
    protected HashMap<String, List<Rule>> cache = new HashMap<String, List<Rule>>();

    
The set of registered Rule instances, in the order that they were originally registered.
/**
     * The set of registered Rule instances, in the order that they were originally registered.
     */
    protected ArrayList<Rule> rules = new ArrayList<Rule>();

    // ------------------------------------------------------------- Properties

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    @Override
    public void setDigester( Digester digester )
    {
        super.setDigester( digester );
        for ( Rule rule : rules )
        {
            rule.setDigester( digester );
        }
    }

    // --------------------------------------------------------- Public Methods

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    @Override
    protected void registerRule( String pattern, Rule rule )
    {
        // to help users who accidently add '/' to the end of their patterns
        int patternLength = pattern.length();
        if ( patternLength > 1 && pattern.endsWith( "/" ) )
        {
            pattern = pattern.substring( 0, patternLength - 1 );
        }

        List<Rule> list = cache.get( pattern );
        if ( list == null )
        {
            list = new ArrayList<Rule>();
            cache.put( pattern, list );
        }
        list.add( rule );
        rules.add( rule );
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    public void clear()
    {
        cache.clear();
        rules.clear();
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    public List<Rule> match( String namespaceURI, String pattern, String name, Attributes attributes )
    {
        // List rulesList = (List) this.cache.get(pattern);
        List<Rule> rulesList = lookup( namespaceURI, pattern );
        if ( ( rulesList == null ) || ( rulesList.size() < 1 ) )
        {
            // Find the longest key, ie more discriminant
            String longKey = "";
            for ( String key : cache.keySet() )
            {
                if ( key.startsWith( "*/" )
                                && ( pattern.equals( key.substring( 2 ) ) || pattern.endsWith( key.substring( 1 ) )
                                && key.length() > longKey.length() ) )
                {
                    // rulesList = (List) this.cache.get(key);
                    rulesList = lookup( namespaceURI, key );
                    longKey = key;
                }
            }
        }
        if ( rulesList == null )
        {
            rulesList = new ArrayList<Rule>();
        }
        return ( rulesList );
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    public List<Rule> rules()
    {
        return ( this.rules );
    }

    // ------------------------------------------------------ Protected Methods

    
Return a List of Rule instances for the specified pattern that also match the specified namespace URI (if any).
If there are no such rules, return null.
Params:
namespaceURI – Namespace URI to match, or null to select matching rules regardless of namespace
           URI
pattern – Pattern to be matched
Returns:
a List of Rule instances for the specified pattern that also match the specified namespace URI (if any)/**
     * Return a List of Rule instances for the specified pattern that also match the specified namespace URI (if any).
     * If there are no such rules, return <code>null</code>.
     *
     * @param namespaceURI Namespace URI to match, or <code>null</code> to select matching rules regardless of namespace
     *            URI
     * @param pattern Pattern to be matched
     * @return a List of Rule instances for the specified pattern that also match the specified namespace URI (if any)
     */
    protected List<Rule> lookup( String namespaceURI, String pattern )
    {
        // Optimize when no namespace URI is specified
        List<Rule> list = this.cache.get( pattern );
        if ( list == null )
        {
            return ( null );
        }
        if ( ( namespaceURI == null ) || ( namespaceURI.length() == 0 ) )
        {
            return ( list );
        }

        // Select only Rules that match on the specified namespace URI
        ArrayList<Rule> results = new ArrayList<Rule>();
        for ( Rule item : list )
        {
            if ( ( namespaceURI.equals( item.getNamespaceURI() ) ) || ( item.getNamespaceURI() == null ) )
            {
                results.add( item );
            }
        }
        return ( results );
    }

}