ResolverUtils.java

/*******************************************************************************
 * Copyright (c) 2009, 2013 Borland Software Corporation and others.
 * 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     Borland Software Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.m2m.internal.qvt.oml.compiler;


import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.util.StringTokenizer;

import org.eclipse.core.runtime.IPath;
import org.eclipse.emf.common.util.URI;
import org.eclipse.m2m.internal.qvt.oml.common.MDAConstants;
import org.eclipse.m2m.internal.qvt.oml.compiler.UnitContents.CSTContents;


public class ResolverUtils {
	
	private ResolverUtils() {
		super();
	}
	
    private static String getNamespaceQuery(URI unitURI) {
        String query = unitURI.query();
		if(query == null || query.trim().length() == 0) {
        	return null;
        }
		
        StringTokenizer tok = new StringTokenizer(query, "&"); //$NON-NLS-1$                
        while (tok.hasMoreElements()) {
            String pair = ((String) tok.nextElement()).trim();
            int index = pair.indexOf('=');

            if (index > 0) {
                String key = pair.substring(0, index);
                if("ns".equals(key.trim())) { //$NON-NLS-1$
                	String val = pair.substring(index + 1).trim();
                	return val.trim();
                }
            }
        }

        return null;
    }
    
    /**
     * Read the name-space value from the query part of the URI if available.
     * @param uri to parse, expecting <code>platform:/plugin/<plugind-id>/<path>/<unit-file>.qvto?ns=org.bar</code> 
     * <b>Note</b>: A temporary solution for compilation of deployed qvto files,
     * in which case the knowledge of the source folder is absent and
     * affects the qualified name resolution 
     */
    public static URI getSourceFolderURI(URI uri) {
    	String ns = getNamespaceQuery(uri);
    	if(ns == null) {
    		return null;
    	}
    	URI result;
    	if(".".equals(ns)) { //$NON-NLS-1$
    		result = uri.trimSegments(1);
    	} else {
    		String[] segments = getNameSegments(ns);
    		result = uri.trimSegments(segments.length + 1);
    	}
    	// add trailing / as for directories
    	return result.appendSegment("").trimQuery(); //$NON-NLS-1$
    }
    
	
	public static String getNamespace(IPath namespacePath, IPath srcContainerPath) {
		if(namespacePath == null || srcContainerPath == null) {
			throw new IllegalArgumentException();
		}
		
		if(namespacePath.equals(srcContainerPath)) {
			// default namespace
			return null;
		}

		int srcContainerDepth = srcContainerPath.segmentCount();
		IPath srcRelativePath = namespacePath.removeFirstSegments(srcContainerDepth);
		
		return getNamespace(srcRelativePath);
	}
	
	public static String getNamespace(IPath srcRelativePath) {
		StringBuilder buf = new StringBuilder();			
		String[] segments = srcRelativePath.segments();
		
		for (int i = 0; i < segments.length; i++) {
			if(i > 0) {
				buf.append('.');
			}
			
			buf.append(segments[i]);	
		}
		
		return buf.toString();
	}

	public static String toQualifiedName(String path) {
		return path.replace(IPath.SEPARATOR, UnitProxy.NAMESPACE_SEP);
	}
	
	public static String toQualifiedName(IPath path) {
		return toQualifiedName(path.toString());
	}
	
	public static String toQualifiedName(String[] nameSegments, int startPos, int endPos) {
		int len = nameSegments.length;
		
		if(	startPos > endPos ||
			(startPos < 0 || startPos >= len) ||
			(endPos < 0 || endPos >= len) ) {
			throw new ArrayIndexOutOfBoundsException("name segment position"); //$NON-NLS-1$
		}
		
		StringBuilder buf = new StringBuilder();
		for (int i = startPos; i <= endPos; i++) {
			if(i > startPos) {
				buf.append(UnitProxy.NAMESPACE_SEP);
			}
			
			buf.append(nameSegments[i]);
		}
		
		return buf.toString();
	}
	
    public static String[] getNameSegments(String qualifiedName) {
		return qualifiedName.split("\\."); //$NON-NLS-1$    	
    }	
	
	public static String toNamespaceRelativeUnitFilePath(String qualifiedName) {
		return qualifiedName.replace(UnitProxy.NAMESPACE_SEP, IPath.SEPARATOR) + MDAConstants.QVTO_FILE_EXTENSION_WITH_DOT;
	}	
	
	public static CSTContents createCSTContents(final String input) {
		if(input == null) {
			throw new IllegalArgumentException();
		}
		
		return new UnitContents.CSTContents() {
			public Reader getContents() throws IOException {				
				return new StringReader(input);
			}
		};
	}
}