/*
 *                 Sun Public License Notice
 * 
 * The contents of this file are subject to the Sun Public License
 * Version 1.0 (the "License"). You may not use this file except in
 * compliance with the License. A copy of the License is available at
 * http://www.sun.com/
 * 
 * The Original Code is NetBeans. The Initial Developer of the Original
 * Code is Sun Microsystems, Inc. Portions Copyright 1997-2004 Sun
 * Microsystems, Inc. All Rights Reserved.
 */

package org.netbeans.modules.ant.freeform;

import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.WeakHashMap;
import org.netbeans.spi.java.queries.SourceLevelQueryImplementation;
import org.netbeans.spi.project.AuxiliaryConfiguration;
import org.openide.filesystems.FileObject;
import org.openide.filesystems.FileUtil;
import org.w3c.dom.Element;

/**
 * Specifies the Java source level (for example 1.4) to use for freeform sources.
 * @author Jesse Glick
 */
final class SourceLevelQueryImpl implements SourceLevelQueryImplementation {
    
    private final FreeformProject project;
    
    /**
     * Map from package roots to source levels.
     */
    private final Map/**/ sourceLevels = new WeakHashMap();
    
    public SourceLevelQueryImpl(FreeformProject project) {
        this.project = project;
    }
    
    public synchronized String getSourceLevel(FileObject file) {
        // Check for cached value.
        Iterator it = sourceLevels.entrySet().iterator();
        while (it.hasNext()) {
            Map.Entry entry = (Map.Entry)it.next();
            FileObject root = (FileObject)entry.getKey();
            if (root == file || FileUtil.isParentOf(root, file)) {
                // Already have it.
                return (String)entry.getValue();
            }
        }
        // Need to compute it.
        AuxiliaryConfiguration aux = (AuxiliaryConfiguration)project.getLookup().lookup(AuxiliaryConfiguration.class);
        assert aux != null;
        Element java = aux.getConfigurationFragment("java-data", FreeformProjectType.NS_JAVA, true); // NOI18N
        if (java == null) {
            return null;
        }
        List/**/ compilationUnits = Util.findSubElements(java);
        it = compilationUnits.iterator();
        while (it.hasNext()) {
            Element compilationUnitEl = (Element)it.next();
            assert compilationUnitEl.getLocalName().equals("compilation-unit") : compilationUnitEl;
            List/**/ packageRoots = Classpaths.findPackageRoots(project, compilationUnitEl);
            Iterator it2 = packageRoots.iterator();
            while (it2.hasNext()) {
                FileObject root = (FileObject)it2.next();
                if (root == file || FileUtil.isParentOf(root, file)) {
                    // Got it. Retrieve source level and cache it (for each root).
                    String lvl = getLevel(compilationUnitEl);
                    it2 = packageRoots.iterator();
                    while (it2.hasNext()) {
                        FileObject root2 = (FileObject)it2.next();
                        sourceLevels.put(root2, lvl);
                    }
                    return lvl;
                }
            }
        }
        // Didn't find anything.
        return null;
    }
    
    /**
     * Get the source level indicated in a compilation unit (or null if none is indicated).
     */
    private String getLevel(Element compilationUnitEl) {
        Element sourceLevelEl = Util.findElement(compilationUnitEl, "source-level", FreeformProjectType.NS_JAVA);
        if (sourceLevelEl != null) {
            return Util.findText(sourceLevelEl);
        } else {
            return null;
        }
    }
    
}