/*
 * Copyright 2005-2010 the original author or authors.
 * 
 * Licensed 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.wamblee.system.graph.component;

import org.wamblee.system.graph.Edge;
import org.wamblee.system.graph.EdgeFilter;

/**
 * Filter used to explicitly connect required and provided interfaces within a
 * container.
 * 
 * @author Erik Brakkee
 */
public class ConnectRequiredProvidedEdgeFilter implements EdgeFilter {
    private String client;

    private String required;

    private String server;

    private String provided;

    /**
     * Creates a new ConnectRequiredProvidedEdgeFilter object.
     * 
     */
    public ConnectRequiredProvidedEdgeFilter(String aClient, String aRequired,
        String aServer, String aProvided) {
        client = aClient;
        required = aRequired;
        server = aServer;
        provided = aProvided;

        if (client == null) {
            throw new IllegalArgumentException(
                "Client component must be specified");
        }
    }

    @Override
    public boolean isViolated(Edge aEdge) {
        if (aEdge.getFrom() instanceof RequiredInterfaceNode &&
            aEdge.getTo() instanceof ProvidedInterfaceNode) {
            return isViolated((RequiredInterfaceNode) aEdge.getFrom(),
                (ProvidedInterfaceNode) aEdge.getTo());
        }

        return false;
    }

    private boolean isViolated(RequiredInterfaceNode aFrom,
        ProvidedInterfaceNode aTo) {
        if (client.equals(aFrom.getComponent().getName()) &&
            ((required == null) || required.equals(aFrom.getRequired()
                .getName()))) {
            // From part matches.
            if (server == null) {
                return true; // all connections are eliminated
            }

            if (server.equals(aTo.getComponent().getName()) &&
                ((provided == null) || provided.equals(aTo.getProvided()
                    .getName()))) {
                // to part matches also
                return false;
            } else {
                // From matches and to doesn't so edgefilter is violated.
                return true;
            }
        } else {
            // From part does not match, restriction does not apply.
            return false;
        }
    }
}