/*
 * Copyright 2008 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;
import org.wamblee.system.graph.EdgeSelector;
import org.wamblee.system.graph.Node;

/**
 * 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;

    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;
        }
    }
}