/*
 * ------------------------------------------------------------------------
 *
 *  Copyright (C) 2003 - 2014
 *  University of Konstanz, Germany and
 *  KNIME GmbH, Konstanz, Germany
 *  Website: http://www.knime.org; Email: contact@knime.org
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License, Version 3, as
 *  published by the Free Software Foundation.
 *
 *  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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, see <http://www.gnu.org/licenses>.
 *
 *  Additional permission under GNU GPL version 3 section 7:
 *
 *  KNIME interoperates with ECLIPSE solely via ECLIPSE's plug-in APIs.
 *  Hence, KNIME and ECLIPSE are both independent programs and are not
 *  derived from each other. Should, however, the interpretation of the
 *  GNU GPL Version 3 ("License") under any applicable laws result in
 *  KNIME and ECLIPSE being a combined program, KNIME GMBH herewith grants
 *  you the additional permission to use and propagate KNIME together with
 *  ECLIPSE with only the license terms in place for ECLIPSE applying to
 *  ECLIPSE and the GNU GPL Version 3 applying for KNIME, provided the
 *  license terms of ECLIPSE themselves allow for the respective use and
 *  propagation of ECLIPSE together with KNIME.
 *
 *  Additional permission relating to nodes for KNIME that extend the Node
 *  Extension (and in particular that are based on subclasses of NodeModel,
 *  NodeDialog, and NodeView) and that only interoperate with KNIME through
 *  standard APIs ("Nodes"):
 *  Nodes are deemed to be separate and independent programs and to not be
 *  covered works.  Notwithstanding anything to the contrary in the
 *  License, the License does not apply to Nodes, you are not required to
 *  license Nodes under the License, and you are granted a license to
 *  prepare and propagate Nodes, in each case even if such Nodes are
 *  propagated with or for interoperation with KNIME.  The owner of a Node
 *  may freely choose the license terms applicable to such Node, including
 *  when such Node is propagated with or for interoperation with KNIME.
 * ---------------------------------------------------------------------
 *
 * Created on Jul 4, 2014 by dietzc
 */
package org.knime.knip.base.nodes.util.dontsave;

import java.io.File;
import java.io.IOException;
import java.util.Arrays;

import org.knime.core.node.CanceledExecutionException;
import org.knime.core.node.ExecutionContext;
import org.knime.core.node.ExecutionMonitor;
import org.knime.core.node.InvalidSettingsException;
import org.knime.core.node.NodeModel;
import org.knime.core.node.NodeSettingsRO;
import org.knime.core.node.NodeSettingsWO;
import org.knime.core.node.port.PortObject;
import org.knime.core.node.port.PortObjectSpec;
import org.knime.core.node.port.inactive.InactiveBranchPortObject;
import org.knime.core.node.port.inactive.InactiveBranchPortObjectSpec;
import org.knime.core.node.workflow.LoopStartNode;

/**
 * @author Christian Dietz, University of Konstanz
 */
public class DontSaveStartNodeModel extends NodeModel implements LoopStartNode {

    // indicating first and second run
    private boolean m_firstRun = true;

    /**
     * Default Constructor
     */
    protected DontSaveStartNodeModel() {
        super(1, 1);
    }

    /** {@inheritDoc} */
    @Override
    protected PortObjectSpec[] configure(final PortObjectSpec[] inSpecs) throws InvalidSettingsException {

        final PortObjectSpec[] result = new PortObjectSpec[getNrOutPorts()];
        if (m_firstRun) {
            result[0] = inSpecs[0];
        } else {
            Arrays.fill(result, InactiveBranchPortObjectSpec.INSTANCE);
        }

        return result;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void loadInternals(final File nodeInternDir, final ExecutionMonitor exec) throws IOException,
            CanceledExecutionException {
        // TODO Auto-generated method stub

    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected PortObject[] execute(final PortObject[] inObjects, final ExecutionContext exec) throws Exception {

        if (m_firstRun) {
            m_firstRun = false;
            return inObjects;
        } else {
            PortObject[] result = new PortObject[getNrOutPorts()];
            Arrays.fill(result, InactiveBranchPortObject.INSTANCE);
            return result;
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void saveInternals(final File nodeInternDir, final ExecutionMonitor exec) throws IOException,
            CanceledExecutionException {
        // nothing to do here
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void saveSettingsTo(final NodeSettingsWO settings) {
        // nothing to do here
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void validateSettings(final NodeSettingsRO settings) throws InvalidSettingsException {
        // nothing to do here
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void loadValidatedSettingsFrom(final NodeSettingsRO settings) throws InvalidSettingsException {
        // nothing to do here
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void reset() {
        m_firstRun = true;
    }
}