/*******************************************************************************
 * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 *
 *******************************************************************************/
package com.liferay.ide.project.ui.jdt;

import com.liferay.ide.project.ui.ProjectUI;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.jdt.ui.text.java.ContentAssistInvocationContext;
import org.eclipse.jdt.ui.text.java.IJavaCompletionProposalComputer;
import org.eclipse.jdt.ui.text.java.JavaContentAssistInvocationContext;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.contentassist.ICompletionProposal;
import org.eclipse.jface.text.contentassist.IContextInformation;

/**
 * @author Simon Jiang
 */

public class ComponentPropertiesCompletionProposalComputer implements IJavaCompletionProposalComputer
{
    @Override
    public List<IContextInformation> computeContextInformation(
        ContentAssistInvocationContext context, IProgressMonitor monitor )
    {
        return Collections.emptyList();
    }

    @Override
    public String getErrorMessage()
    {
        return null;
    }

    @Override
    public void sessionEnded()
    {
    }

    @Override
    public void sessionStarted()
    {
    }

    @Override
    public List<ICompletionProposal> computeCompletionProposals(
        ContentAssistInvocationContext context, IProgressMonitor monitor )
    {
        List<ICompletionProposal> propsoalList = new ArrayList<ICompletionProposal>();
        try
        {
            JavaContentAssistInvocationContext jdtContext = (JavaContentAssistInvocationContext) context;
            int invocationOffset = jdtContext.getInvocationOffset();
            IDocument document = jdtContext.getDocument();
            IRegion lineRegion = document.getLineInformationOfOffset( invocationOffset );
            String source = "";
            String wholeLine = document.get( lineRegion.getOffset(), lineRegion.getLength() );
            int wholeLineEndPos = lineRegion.getOffset() + lineRegion.getLength();
            int quotPos = wholeLine.indexOf( "\"" );
            boolean hasQuot = false;
            int replaceEndPos = invocationOffset;

            while( ( quotPos + lineRegion.getOffset() ) < wholeLineEndPos && quotPos != -1 )
            {
                int lastQuotPos = quotPos;
                quotPos = wholeLine.indexOf( "\"", lastQuotPos + 1 );

                if( ( quotPos + lineRegion.getOffset() ) >= invocationOffset )
                {
                    hasQuot = true;
                    int prefixStartPos = lineRegion.getOffset() + lastQuotPos + 1;
                    source = document.get( prefixStartPos, invocationOffset - prefixStartPos ).trim();

                    if( ( quotPos + lineRegion.getOffset() ) > wholeLineEndPos )
                    {
                        replaceEndPos = wholeLineEndPos;
                    }
                    else
                    {
                        replaceEndPos = quotPos + lineRegion.getOffset();
                    }
                    break;
                }
            }

            String candidate = source.replace( "\"", "" );

            if( candidate != null && hasQuot )
            {
                int replaceStartPos = invocationOffset - candidate.trim().length();

                for( int i = 0; i < LiferayComponentProperties.CODE_ASSISTANT_RESOURCE.length - 1; i++ )
                {
                    final String[] propertyAssist = LiferayComponentProperties.CODE_ASSISTANT_RESOURCE[i];
                    final String propertyKey = propertyAssist[0];
                    final String propertyComment = propertyAssist[2];

                    if( ( candidate.length() > 0 ) && ( !propertyKey.startsWith( candidate ) ) )
                    {
                        continue;
                    }

                    final String replaceString = propertyKey + "=";
                    propsoalList.add(
                        new ComponentPropertyCompletionProposal(
                            jdtContext, 
                            replaceString, 
                            jdtContext.getInvocationOffset(), 
                            replaceString.length(),
                            ProjectUI.getDefault().getImageRegistry().get( ProjectUI.PROPERTIES_IMAGE_ID ), 
                            propertyKey,
                            0, 
                            replaceStartPos, 
                            replaceEndPos, 
                            propertyComment, 
                            source 
                        ) 
                    );
                }
            }
        }
        catch( BadLocationException ex )
        {
            ProjectUI.logError( ex );
        }
        return propsoalList;
    }
}