/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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.
 */
package org.apache.jena.security.query.rewriter;

import com.hp.hpl.jena.graph.Node;
import com.hp.hpl.jena.graph.Triple;
import com.hp.hpl.jena.sparql.core.Var;
import com.hp.hpl.jena.sparql.engine.binding.Binding;
import com.hp.hpl.jena.sparql.expr.Expr;
import com.hp.hpl.jena.sparql.expr.ExprFunctionN;
import com.hp.hpl.jena.sparql.expr.ExprList;
import com.hp.hpl.jena.sparql.expr.ExprVar;
import com.hp.hpl.jena.sparql.expr.ExprVisitor;
import com.hp.hpl.jena.sparql.expr.NodeValue;
import com.hp.hpl.jena.sparql.function.FunctionEnv;
import com.hp.hpl.jena.sparql.graph.NodeTransform;
import java.util.List;

import org.apache.jena.security.SecurityEvaluator;
import org.apache.jena.security.SecurityEvaluator.Action;
import org.apache.jena.security.SecurityEvaluator.SecNode;
import org.apache.jena.security.SecurityEvaluator.SecTriple;
import org.apache.jena.security.impl.SecuredItemImpl;

public class SecuredFunction extends ExprFunctionN
{
	private final SecurityEvaluator securityEvaluator;
	private final List<Node> variables;
	private final List<Triple> bgp;
	private final SecNode graphIRI;
	
	private static ExprList createArgs( List<Node> variables )
	{
		ExprList retval = new ExprList();
		for (Node n : variables )
		{
			retval.add( new ExprVar( n ));
		}
		return retval;
	}

	public SecuredFunction( final SecNode graphIRI,
			final SecurityEvaluator securityEvaluator,
			final List<Node> variables, final List<Triple> bgp )
	{
		super(String.format("<java:%s>", SecuredFunction.class.getName() ), createArgs( variables));
		//, 
		//		new ElementTriplesBlock( BasicPattern.wrap(bgp) ),
		//		new OpBGP( BasicPattern.wrap(bgp) )
		//		);
		this.securityEvaluator = securityEvaluator;
		this.variables = variables;
		this.bgp = bgp;
		this.graphIRI = graphIRI;
	}
	
	private boolean checkAccess( Binding values )
	{
		for (final Triple t : bgp)
		{
			final SecTriple secT = createSecTriple(t, values);
			if (!securityEvaluator.evaluate(Action.Read, graphIRI, secT))
			{
				return false;
			}
		}
		return true;
	}

	private SecTriple createSecTriple( final Triple t, final Binding values )
	{
		int idx = variables.indexOf(t.getSubject());

		final SecNode s = SecuredItemImpl.convert(idx ==-1 ? t.getSubject()
				: values.get(Var.alloc( variables.get(idx))));

		idx = variables.indexOf(t.getPredicate());
		final SecNode p = SecuredItemImpl.convert(idx == -1 ? t
				.getPredicate() 
				: values.get(Var.alloc( variables.get(idx))));
		idx = variables.indexOf(t.getObject());
		final SecNode o = SecuredItemImpl.convert(idx == -1 ? t.getObject()
				: values.get(Var.alloc( variables.get(idx))));
		return new SecTriple(s, p, o);
	}


	@Override
	public Expr copySubstitute( Binding binding, boolean foldConstants )
	{
		return this;
	}

	@Override
	public Expr applyNodeTransform( NodeTransform transform )
	{
		return this;
	}

	@Override
	public void visit( ExprVisitor visitor )
	{
		visitor.visit( this );
	}

	@Override
	protected NodeValue eval( List<NodeValue> args )
	{
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	protected Expr copy( ExprList newArgs )
	{
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	protected NodeValue evalSpecial( Binding binding, FunctionEnv env )
	{
		return NodeValue.booleanReturn( checkAccess( binding ));
	}


	
}

@@ -3876,24 +3876,21 @@
 rride%0A%09p
-rotected
+ublic
  Expr co

Align SecuredFunction with JENA-630 changes