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package it.uniroma2.art.semanticturkey.changetracking.sail;

import org.eclipse.rdf4j.model.IRI;
import org.eclipse.rdf4j.model.Resource;
import org.eclipse.rdf4j.model.Value;
import org.eclipse.rdf4j.sail.UpdateContext;

/**
 * An {@link UpdateHandler} managing a flag, telling whether a connection is read-only or not.
 * 
 * @author Manuel Fiorelli
 */
public class FlagUpdateHandler extends BaseUpdateHandler {
	private boolean readonly = true;
	
	@Override
	public void addStatement(Resource subj, IRI pred, Value obj, Resource[] newContexts) {
		readonly = false;
	}

	@Override
	public void addStatement(UpdateContext modify, Resource subj, IRI pred, Value obj,
			Resource[] newContexts) {
		readonly = false;
	}

	@Override
	public void removeStatements(Resource subj, IRI pred, Value obj, Resource[] newContexts) {
		readonly = false;
	}

	@Override
	public void removeStatement(UpdateContext modify, Resource subj, IRI pred, Value obj,
			Resource[] newContexts) {
		readonly = false;
	}

	@Override
	public void clear(Resource[] contexts) {
		readonly = false;
	}

	/*
	 * Namespace operations do not modify the actual triples, and as such they are not reported in history not
	 * vetted by validation. Actually, some triple stores seem not to allow rollback from such operations at
	 * all. Therefore, we consider these operations as part of read-only transactions (which in any case will
	 * be committed as well).
	 */
	
	@Override
	public void setNamespace(String prefix, String name) {
//		readonly = false;
	}
	
	@Override
	public void clearNamespaces() {
//		readonly = false;
	}

	@Override
	public void removeNamespace(String prefix) {
//		readonly = false;
	}
	
	@Override
	public boolean isReadOnly() {
		return readonly;
	}
	
	@Override
	public void clearHandler(IRI...contexts) {
		readonly = true;
	}

}