/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2011 by Rapid-I and the contributors
 *
 *  Complete list of developers available at our web site:
 *
 *       http://rapid-i.com
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see http://www.gnu.org/licenses/.
 */
package com.rapidminer.io.process.rules;

import java.util.Collections;
import java.util.List;

import com.rapidminer.gui.tools.VersionNumber;
import com.rapidminer.io.process.XMLImporter;
import com.rapidminer.operator.Operator;
import com.rapidminer.operator.OperatorChain;
import com.rapidminer.operator.SimpleOperatorChain;
import com.rapidminer.operator.ports.InputPort;
import com.rapidminer.operator.ports.InputPorts;
import com.rapidminer.operator.ports.OutputPort;
import com.rapidminer.operator.ports.OutputPorts;
/**
 * 
 * @author Sebastian Land
 */
public class PassthroughShortcutRule extends AbstractGenericParseRule {
	private static final VersionNumber APPLIES_UNTIL = new VersionNumber(5, 0, 0, false, 0, false, 0);
	
	@Override
	public String apply(final Operator operator, VersionNumber processVersion, final XMLImporter importer) {
		if (operator.getClass().equals(SimpleOperatorChain.class) && (processVersion == null || processVersion.compareTo(APPLIES_UNTIL) < 0)) {
			importer.doAfterAutoWire(new Runnable() {
				@Override
				public void run() {
					OperatorChain chain = (OperatorChain)operator;					
					InputPorts  inputs  = chain.getInputPorts();
					OutputPorts sources = chain.getSubprocess(0).getInnerSources();
					InputPorts  sinks   = chain.getSubprocess(0).getInnerSinks();
					OutputPorts outputs = chain.getOutputPorts();
					boolean found;
					do {
						found = false;
						for (int leftIndex = 0; leftIndex < sources.getNumberOfPorts(); leftIndex++) {
							OutputPort source = sources.getPortByIndex(leftIndex);
							if (!source.isConnected()) {
								continue;
							}
							InputPort sink = source.getDestination();
							if (sinks.getAllPorts().contains(sink)) {								
								int rightIndex = sinks.getAllPorts().indexOf(sink);
								InputPort correspondingInput = inputs.getPortByIndex(leftIndex);								
								OutputPort correspondingOutput = outputs.getPortByIndex(rightIndex);
								if (correspondingInput.isConnected() && correspondingOutput.isConnected()) {
									OutputPort originalSource   = correspondingInput.getSource();
									InputPort  finalDestination = correspondingOutput.getDestination();								
									originalSource.lock();
									finalDestination.lock();

									originalSource.disconnect();
									source.disconnect();
									correspondingOutput.disconnect();

									originalSource.connectTo(finalDestination);

									originalSource.unlock();
									finalDestination.unlock();
									found = true;

									importer.addMessage("The connection from <code>"+source.getSpec()+"</code> to <code>"+sink+"</code> was replaced by the direct connection from <code>"+originalSource.getSpec()+"</code> to <code>"+finalDestination.getSpec()+"</code>.");
								}
							}
						}
					} while (found);
				}			
			});
		}
		return null;
	}

	@Override
	public List<String> getApplicableOperatorKeys() {
		return Collections.singletonList("subprocess");
	}

}