content: /*******************************************************************************
   * Copyright (c) 2000, 2008 IBM 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:
   *     IBM Corporation - initial API and implementation
   *******************************************************************************/
  package org.eclipse.wst.jsdt.internal.ui.text.correction;
  
  import java.util.Arrays;
  import java.util.HashSet;
  import java.util.Set;
  
  import org.eclipse.core.expressions.EvaluationContext;
  import org.eclipse.core.expressions.EvaluationResult;
  import org.eclipse.core.expressions.Expression;
  import org.eclipse.core.expressions.ExpressionConverter;
  import org.eclipse.core.expressions.ExpressionTagNames;
  import org.eclipse.core.runtime.CoreException;
  import org.eclipse.core.runtime.IConfigurationElement;
  import org.eclipse.core.runtime.IStatus;
  import org.eclipse.wst.jsdt.core.IJavaScriptUnit;
  import org.eclipse.wst.jsdt.core.IJavaScriptModelMarker;
  import org.eclipse.wst.jsdt.core.IJavaScriptProject;
  import org.eclipse.wst.jsdt.core.JavaScriptCore;
  import org.eclipse.wst.jsdt.internal.corext.util.JavaModelUtil;
  import org.eclipse.wst.jsdt.internal.ui.JavaScriptPlugin;
  import org.eclipse.wst.jsdt.internal.ui.dialogs.StatusInfo;
  
  public final class ContributedProcessorDescriptor {
  
  	private final IConfigurationElement fConfigurationElement;
  	private Object fProcessorInstance;
  	private Boolean fStatus;
  	private boolean fLastResult;
  	private String fRequiredSourceLevel;
  	private final Set fHandledMarkerTypes;
  
  	private static final String ID= "id"; //$NON-NLS-1$
  	private static final String CLASS= "class"; //$NON-NLS-1$
  	
  	private static final String REQUIRED_SOURCE_LEVEL= "requiredSourceLevel"; //$NON-NLS-1$
  	
  	private static final String HANDLED_MARKER_TYPES= "handledMarkerTypes"; //$NON-NLS-1$
  	private static final String MARKER_TYPE= "markerType"; //$NON-NLS-1$
  	
  	public ContributedProcessorDescriptor(IConfigurationElement element, boolean testMarkerTypes) {
  		fConfigurationElement= element;
  		fProcessorInstance= null;
  		fStatus= null; // undefined
  		if (fConfigurationElement.getChildren(ExpressionTagNames.ENABLEMENT).length == 0) {
  			fStatus= Boolean.TRUE;
  		}
  		fRequiredSourceLevel= element.getAttribute(REQUIRED_SOURCE_LEVEL);
  		fHandledMarkerTypes= testMarkerTypes ? getHandledMarkerTypes(element) : null;
  	}
  
  	private Set getHandledMarkerTypes(IConfigurationElement element) {
  		HashSet map= new HashSet(7);
  		IConfigurationElement[] children= element.getChildren(HANDLED_MARKER_TYPES);
  		for (int i= 0; i < children.length; i++) {
  			IConfigurationElement[] types= children[i].getChildren(MARKER_TYPE);
  			for (int k= 0; k < types.length; k++) {
  				String attribute= types[k].getAttribute(ID);
  				if (attribute != null) {
  					map.add(attribute);
  				}
  			}
  		}
  		if (map.isEmpty()) {
  			map.add(IJavaScriptModelMarker.JAVASCRIPT_MODEL_PROBLEM_MARKER);
  			map.add(IJavaScriptModelMarker.BUILDPATH_PROBLEM_MARKER);
  			map.add(IJavaScriptModelMarker.TASK_MARKER);
  		}
  		return map;
  	}
  
  	public IStatus checkSyntax() {
  		IConfigurationElement[] children= fConfigurationElement.getChildren(ExpressionTagNames.ENABLEMENT);
  		if (children.length > 1) {
  			String id= fConfigurationElement.getAttribute(ID);
  			return new StatusInfo(IStatus.ERROR, "Only one < enablement > element allowed. Disabling " + id); //$NON-NLS-1$
  		}
  		return new StatusInfo(IStatus.OK, "Syntactically correct quick assist/fix processor"); //$NON-NLS-1$
  	}
  
  	private boolean matches(IJavaScriptUnit cunit) {
  		if (fRequiredSourceLevel != null) {
  			String current= cunit.getJavaScriptProject().getOption(JavaScriptCore.COMPILER_SOURCE, true);
  			if (JavaModelUtil.isVersionLessThan(current, fRequiredSourceLevel)) {
  				return false;
  			}
  		}
  		
  		if (fStatus != null) {
  			return fStatus.booleanValue();
  		}
  
  		IConfigurationElement[] children= fConfigurationElement.getChildren(ExpressionTagNames.ENABLEMENT);
  		if (children.length == 1) {
  			try {
  				ExpressionConverter parser= ExpressionConverter.getDefault();
  				Expression expression= parser.perform(children[0]);
  				EvaluationContext evalContext= new EvaluationContext(null, cunit);
  				evalContext.addVariable("compilationUnit", cunit); //$NON-NLS-1$
  				IJavaScriptProject javaProject= cunit.getJavaScriptProject();
  				String[] natures= javaProject.getProject().getDescription().getNatureIds();
  				evalContext.addVariable("projectNatures", Arrays.asList(natures)); //$NON-NLS-1$
  				evalContext.addVariable("sourceLevel", javaProject.getOption(JavaScriptCore.COMPILER_SOURCE, true)); //$NON-NLS-1$
  				fLastResult= !(expression.evaluate(evalContext) != EvaluationResult.TRUE);
  				return fLastResult;
  			} catch (CoreException e) {
  				JavaScriptPlugin.log(e);
  			}
  		}
  		fStatus= Boolean.FALSE;
  		return false;
  	}
  	
  	public Object getProcessor(IJavaScriptUnit cunit) throws CoreException {
  		if (matches(cunit)) {
  			if (fProcessorInstance == null) {
  				fProcessorInstance= fConfigurationElement.createExecutableExtension(CLASS);
  			}
  			return fProcessorInstance;
  		}
  		return null;
  	}
  	
  	public boolean canHandleMarkerType(String markerType) {
  		return fHandledMarkerTypes == null || fHandledMarkerTypes.contains(markerType);
  	}
  	
  }
  