/*
 *  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.operator.ports.impl;

import com.rapidminer.Process;
import com.rapidminer.operator.DebugMode;
import com.rapidminer.operator.IOObject;
import com.rapidminer.operator.ports.InputPort;
import com.rapidminer.operator.ports.OutputPort;
import com.rapidminer.operator.ports.OutputPorts;
import com.rapidminer.operator.ports.Port;
import com.rapidminer.operator.ports.PortException;
import com.rapidminer.operator.ports.Ports;
import com.rapidminer.operator.ports.metadata.MetaData;

/**
 * @author Simon Fischer
 */

public class OutputPortImpl extends AbstractPort implements OutputPort {

	private InputPort connectedTo;

	private MetaData metaData;

	private MetaData realMetaData;
	
	/** Use the factory method {@link OutputPorts#createPort()} to create OutputPorts. */
	protected OutputPortImpl(Ports<? extends Port> owner, String name, boolean simulatesStack) {
		super(owner, name, simulatesStack);		
	}

	@Override
	public void clear(int clearFlags) {
		super.clear(clearFlags);
		if ((clearFlags & CLEAR_REAL_METADATA) > 0) {
			realMetaData = null;
		}
		if ((clearFlags & CLEAR_METADATA) > 0) {
			metaData = null;
		}
	}

	private void assertConnected() throws PortException {
		if (this.connectedTo == null) {
			throw new PortException(this, "Not connected.");
		}
	}

	/*
	private void assertDisconnected() throws PortException {
		if (this.connectedTo != null) {
			throw new PortException(this, "Already connected.");
		}
	}
	 */

	@Override
	public void connectTo(InputPort inputPort) throws PortException {
		if (this.connectedTo == inputPort) {
			return;
		}
		if (inputPort.getPorts().getOwner().getConnectionContext() !=
			this.getPorts().getOwner().getConnectionContext()) {
			throw new PortException("Cannot connect " + getSpec() + " to " + inputPort.getSpec() + 
					": ports must be in the same subprocess, but are in " +
					this.getPorts().getOwner().getConnectionContext().getName() + " and " +
					inputPort.getPorts().getOwner().getConnectionContext().getName() + ".");
		}
		boolean destConnected = inputPort.isConnected();
		boolean sourceConnected = this.isConnected();
		boolean bothConnected = destConnected && sourceConnected;
		boolean connected = destConnected || sourceConnected;
		if (connected) {
			if (bothConnected) {
				throw new CannotConnectPortException(this, inputPort, this.getDestination(), inputPort.getSource());
			} else if (sourceConnected) {
				throw new CannotConnectPortException(this, inputPort, this.getDestination());
			} else {
				throw new CannotConnectPortException(this, inputPort, inputPort.getSource());
			}
		}		
		this.connectedTo = inputPort;
		((InputPortImpl)inputPort).connect(this);
		fireUpdate(this);
	}

	@Override
	public void disconnect() throws PortException {
		assertConnected();
		((InputPortImpl)this.connectedTo).connect(null);
		this.connectedTo.receive(null);
		this.connectedTo.receiveMD(null);
		this.connectedTo = null;
		fireUpdate(this);
	}

	@Override
	public void deliver(IOObject object) {	
		// registering in history of object
		if (object != null)
			object.appendOperatorToHistory(getPorts().getOwner().getOperator(), this);
		
		// delivering data
		setData(object);
		if (connectedTo != null) {
			this.connectedTo.receive(object);
		}
		
		Process process = getPorts().getOwner().getOperator().getProcess();
		if ((process != null) && (process.getDebugMode() == DebugMode.COLLECT_METADATA_AFTER_EXECUTION)) {
			if (object == null) {
				this.realMetaData = null;	
			} else {
				this.realMetaData = MetaData.forIOObject(object);
			}
		} else {
			this.realMetaData = null;
		}

	}

	@Override
	public void deliverMD(MetaData md) {
		this.metaData = md;
		if (connectedTo != null) {
			this.connectedTo.receiveMD(md);			
		}		
	}

	@Override
	public MetaData getMetaData() {
		if (realMetaData != null) {
			return realMetaData;
		} else {
			return metaData;
		}
	}

	@Override
	public InputPort getDestination() {		
		return connectedTo;		
	}

	@Override
	public String getDescription() {
		return "";
	}

	@Override
	public boolean isConnected() {
		return connectedTo != null;
	}

	@Override
	public boolean shouldAutoConnect() {
		return getPorts().getOwner().getOperator().shouldAutoConnect(this);
	}
}