package org.eclipse.wst.sse.ui.internal.reconcile;

import org.eclipse.jface.text.Position;
import org.eclipse.jface.text.source.ISourceViewer;
import org.eclipse.wst.sse.core.StructuredModelManager;
import org.eclipse.wst.sse.core.internal.provisional.IStructuredModel;
import org.eclipse.wst.sse.core.internal.provisional.IndexedRegion;
import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocumentRegion;

/**
 * Uses IStructuredModel nodes to check "overlaps()" when getting annotations to remove.
 */
public abstract class StructuredTextReconcilingStrategy extends AbstractStructuredTextReconcilingStrategy {
	

	public StructuredTextReconcilingStrategy(ISourceViewer sourceViewer) {
		super(sourceViewer);
	}

	/**
	 * Checks if this position overlaps any of the StructuredDocument regions'
	 * correstponding IndexedRegion.
	 * 
	 * @param pos
	 * @param dr
	 * @return true if the position overlaps any of the regions, otherwise
	 *         false.
	 */
	protected boolean overlaps(Position pos, IStructuredDocumentRegion[] sdRegions) {
		int start = -1;
		int end = -1;
		for (int i = 0; i < sdRegions.length; i++) {
		    if(!sdRegions[i].isDeleted()) {
    			IndexedRegion corresponding = getCorrespondingNode(sdRegions[i]);
                if(corresponding != null) {
        			if (start == -1 || start > corresponding.getStartOffset())
        				start = corresponding.getStartOffset();
        			if (end == -1 || end < corresponding.getEndOffset())
        				end = corresponding.getEndOffset();
                }
            }
		}
		return pos.overlapsWith(start, end - start);
	}

	/**
	 * Returns the corresponding node for the StructuredDocumentRegion.
	 * 
	 * @param sdRegion
	 * @return the corresponding node for sdRegion
	 */
	protected IndexedRegion getCorrespondingNode(IStructuredDocumentRegion sdRegion) {
		IStructuredModel sModel = StructuredModelManager.getModelManager().getExistingModelForRead(getDocument());
        IndexedRegion indexedRegion = null;
        try {
            if (sModel != null) 
                indexedRegion = sModel.getIndexedRegion(sdRegion.getStart());    
        } finally {
            if (sModel != null)
                sModel.releaseFromRead();
        }
        return indexedRegion;
    }

}