package org.drools.eclipse.flow.ruleflow.view.property.constraint;



/*

 * Copyright 2005 JBoss Inc

 * 

 * Licensed 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.Collection;

import java.util.Collections;

import java.util.List;

import java.util.Map;

import java.util.regex.Matcher;



import org.drools.eclipse.DroolsEclipsePlugin;

import org.drools.eclipse.editors.completion.CompletionUtil;

import org.drools.eclipse.editors.completion.DefaultCompletionProcessor;

import org.drools.eclipse.editors.completion.RuleCompletionProcessor;

import org.drools.eclipse.editors.completion.RuleCompletionProposal;

import org.eclipse.core.resources.IFile;

import org.eclipse.core.runtime.CoreException;

import org.eclipse.jdt.core.IJavaProject;

import org.eclipse.jdt.core.JavaCore;

import org.eclipse.jface.text.IDocument;

import org.eclipse.jface.text.ITextViewer;

import org.eclipse.ui.IEditorPart;

import org.eclipse.ui.IFileEditorInput;

import org.eclipse.ui.IWorkbench;

import org.eclipse.ui.IWorkbenchPage;

import org.eclipse.ui.IWorkbenchWindow;

import org.eclipse.ui.PlatformUI;



/**

 * Completion for ruleflow constraints. 

 * 

 * @author <a href="mailto:kris_verlaenen@hotmail.com">Kris Verlaenen</a>

 */

public class GlobalCompletionProcessor extends DefaultCompletionProcessor {



	public GlobalCompletionProcessor() {

		super(null);

	}

	

	public IEditorPart getEditor() {

		IWorkbench workbench = PlatformUI.getWorkbench();

		if (workbench != null) { 

			IWorkbenchWindow workbenchWindow = workbench.getActiveWorkbenchWindow();

			if (workbenchWindow != null) {

				IWorkbenchPage workbenchPage = workbenchWindow.getActivePage(); 

				if (workbenchPage != null) {

					return workbenchPage.getActiveEditor();

				}

			}

		}

		return null;

	}



    protected List getCompletionProposals(ITextViewer viewer,

            int documentOffset) {

		try {

			IDocument doc = viewer.getDocument();

			String backText = readBackwards(documentOffset, doc);

			String prefix = CompletionUtil.stripLastWord(backText);

			return getPossibleProposals(viewer, documentOffset, backText, prefix);

		} catch (Throwable t) {

			DroolsEclipsePlugin.log(t);

		}

		return null;

	}



    

    public List getImports() {

    	return Collections.EMPTY_LIST;

    }

    

    public List getGlobals() {

    	return Collections.EMPTY_LIST;

    }

    

    protected IJavaProject getCurrentJavaProject() {

    	IEditorPart editor = getEditor();

    	if (editor != null && editor.getEditorInput() instanceof IFileEditorInput) {

			IFile file = ((IFileEditorInput) editor.getEditorInput()).getFile();

	    	try {

	    		if (file.getProject().getNature("org.eclipse.jdt.core.javanature") != null) {

	    			return JavaCore.create(file.getProject());

	    		}

	    	} catch (CoreException e) {

	    		// do nothing

	    	}

		}

    	return null;

    }

    

    protected List getPossibleProposals(ITextViewer viewer,

            int documentOffset,

            String backText,

            final String prefix) {

		List list = new ArrayList();

		list.add(new RuleCompletionProposal(documentOffset - prefix.length(), prefix.length(), "global", "global "));

		DefaultCompletionProcessor.filterProposalsOnPrefix(prefix, list);

		return list;

	}



}