/*******************************************************************************
 * Copyright (c) 2004, 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 - Initial API and implementation
 *******************************************************************************/
package org.eclipse.cdt.internal.core.dom;

import java.util.Arrays;
import java.util.Iterator;

import org.eclipse.cdt.core.dom.CDOM;
import org.eclipse.cdt.core.dom.ICodeReaderFactory;
import org.eclipse.cdt.core.model.ITranslationUnit;
import org.eclipse.cdt.core.model.IWorkingCopy;
import org.eclipse.cdt.core.model.IWorkingCopyProvider;
import org.eclipse.cdt.core.parser.CodeReader;
import org.eclipse.cdt.core.parser.ICodeReaderCache;
import org.eclipse.cdt.core.parser.ParserUtil;
import org.eclipse.cdt.internal.core.parser.EmptyIterator;

/**
 * @author jcamelon
 */
public class PartialWorkingCopyCodeReaderFactory 
        implements ICodeReaderFactory {

    private final IWorkingCopyProvider provider;
	private ICodeReaderCache cache = null;

    /**
     * @param provider
     */
    public PartialWorkingCopyCodeReaderFactory(IWorkingCopyProvider provider) {
        this.provider = provider;
		cache = SavedCodeReaderFactory.getInstance().getCodeReaderCache();
    }

    /* (non-Javadoc)
     * @see org.eclipse.cdt.core.dom.ICodeReaderFactory#getUniqueIdentifier()
     */
    public int getUniqueIdentifier() {
        return CDOM.PARSE_WORKING_COPY_WITH_SAVED_INCLUSIONS;
    }

    /* (non-Javadoc)
     * @see org.eclipse.cdt.core.dom.ICodeReaderFactory#createCodeReaderForTranslationUnit(java.lang.String)
     */
    public CodeReader createCodeReaderForTranslationUnit(String path) {
		return checkWorkingCopyThenCache(path);
    }

    public CodeReader createCodeReaderForTranslationUnit(ITranslationUnit tu) {
		return new CodeReader(tu.getPath().toOSString(), tu.getContents());
    }
    
	/**
	 * @param path
	 * @return
	 */
	protected CodeReader checkWorkingCopyThenCache(String path) {
		char [] buffer = ParserUtil.findWorkingCopyBuffer( path, createWorkingCopyIterator() );
		if( buffer != null )
			return new CodeReader(path, buffer);
		return cache.get( path );
	}

    /* (non-Javadoc)
     * @see org.eclipse.cdt.core.dom.ICodeReaderFactory#createCodeReaderForInclusion(java.lang.String)
     */
    public CodeReader createCodeReaderForInclusion(String path) {
        return cache.get( path );
    }

    /**
     * @return
     */
    @SuppressWarnings("unchecked")
	protected Iterator<IWorkingCopy> createWorkingCopyIterator() {
        if( provider == null ) return EmptyIterator.EMPTY_ITERATOR;
        return Arrays.asList( provider.getWorkingCopies() ).iterator();
    }

	/* (non-Javadoc)
     * @see org.eclipse.cdt.core.dom.ICodeReaderFactory#getCodeReaderCache()
     */
	public ICodeReaderCache getCodeReaderCache() {
		return cache;
	}

}
