RxAssembly.java

/*******************************************************************************
 * Copyright (c) 2006-2013, Cloudsmith Inc.
 * The code, documentation and other materials contained herein have been
 * licensed under the Eclipse Public License - v 1.0 by the copyright holder
 * listed above, as the Initial Contributor under such license. The text of
 * such license is available at www.eclipse.org.
 ******************************************************************************/

package org.eclipse.buckminster.core.common.model;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;

import org.eclipse.buckminster.core.CorePlugin;
import org.eclipse.buckminster.core.Messages;
import org.eclipse.buckminster.core.helpers.TextUtils;
import org.eclipse.buckminster.runtime.Logger;
import org.eclipse.buckminster.sax.AbstractSaxableElement;
import org.eclipse.buckminster.sax.Utils;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.osgi.util.NLS;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;

/**
 * @author Thomas Hallgren
 */
public class RxAssembly extends AbstractSaxableElement {
	public static final String TAG = "rxAssembly"; //$NON-NLS-1$

	public static final String ATTR_REPLACEMENT = "replacement"; //$NON-NLS-1$

	private final List<RxPart> parts;

	private final Pattern pattern;

	private final List<RxPart> parameters = new ArrayList<RxPart>();

	public RxAssembly(List<RxPart> parts) throws CoreException, PatternSyntaxException {
		this.parts = Utils.createUnmodifiableList(parts);

		StringBuilder bld = new StringBuilder();
		bld.append('^');
		for (RxPart part : parts)
			part.addPattern(bld, parameters);
		bld.append('$');

		String patternStr = bld.toString();
		pattern = Pattern.compile(patternStr);
		CorePlugin.getLogger().debug("URI pattern %s created", patternStr); //$NON-NLS-1$
	}

	@Override
	public String getDefaultTag() {
		return TAG;
	}

	public Map<String, String> getMatchMap(CharSequence input) {
		if (input == null)
			return null;

		Logger logger = CorePlugin.getLogger();
		Matcher m = pattern.matcher(input);
		if (!m.matches()) {
			logger.debug("URI pattern does not match %s", input); //$NON-NLS-1$
			return null;
		}

		int groupCount = m.groupCount();
		int top = parameters.size();
		if (logger.isDebugEnabled()) {
			logger.debug("URI pattern captured %d groups in %s", Integer.valueOf(groupCount), input); //$NON-NLS-1$
		}

		if (top != groupCount) {
			logger.warning(NLS.bind(Messages.URI_pattern_group_count_was_0_expected_1, Integer.valueOf(groupCount), Integer.valueOf(top)));
			top = groupCount;
		}

		if (top == 0)
			return Collections.emptyMap();

		HashMap<String, String> matchMap = new HashMap<String, String>();

		for (int idx = 0; idx < top; ++idx) {
			RxPart param = parameters.get(idx);
			String value = TextUtils.notEmptyString(m.group(idx + 1));
			if (value != null) {
				logger.debug("Assigning URI pattern parameter %s=\"%s\"", param.getName(), value); //$NON-NLS-1$
				matchMap.put(param.getName(), value);
			}
		}
		return matchMap;
	}

	public Pattern getPattern() {
		return pattern;
	}

	@Override
	protected void emitElements(ContentHandler handler, String namespace, String prefix) throws SAXException {
		for (RxPart part : parts)
			part.toSax(handler, namespace, prefix, part.getDefaultTag());
	}
}