/*
 *  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.metadata;

import java.util.Collections;

import com.rapidminer.example.ExampleSet;
import com.rapidminer.operator.Operator;
import com.rapidminer.operator.SimpleProcessSetupError;
import com.rapidminer.operator.ProcessSetupError.Severity;
import com.rapidminer.operator.ports.InputPort;
import com.rapidminer.operator.ports.quickfix.ParameterSettingQuickFix;

/**
 * This Precondition checks whether two example indices given by parameters lying in the size of the example set. If
 * only a starting Parameter is given and the end parameter is null, it will be treated as single index.
 * 
 * @author Sebastian Land
 * 
 */
public class ExampleSetSizePrecondition extends AbstractPrecondition {

	private String startParameter;
	private String endParameter;
	private Operator operator;

	public ExampleSetSizePrecondition(InputPort inputPort, Operator operator, String startParameter) {
		this(inputPort, operator, startParameter, null);
	}

	public ExampleSetSizePrecondition(InputPort inputPort, Operator operator, String startParameter, String endParameter) {
		super(inputPort);

		this.startParameter = startParameter;
		this.endParameter = endParameter;
		this.operator = operator;
	}

	@Override
	public void check(MetaData metaData) {
		final InputPort inputPort = getInputPort();
		if (metaData == null) {
			inputPort.addError(new InputMissingMetaDataError(inputPort, ExampleSet.class, null));
		} else {
			if (metaData instanceof ExampleSetMetaData) {
				ExampleSetMetaData emd = (ExampleSetMetaData) metaData;

				try {
					int startIndex = operator.getParameterAsInt(startParameter);
					if (emd.getNumberOfExamples().isAtLeast(startIndex) == MetaDataInfo.NO) {
						createError(Severity.ERROR, 
								Collections.singletonList(new ParameterSettingQuickFix(operator, startParameter, (emd.getNumberOfExamples().getValue() - ((endParameter == null)? 0 :1)) + "")), 
								"exampleset.parameter_value_exceeds_exampleset_size", startParameter, startIndex + "");
					}
					if (endParameter != null) {
						int endIndex = operator.getParameterAsInt(endParameter);
						if (emd.getNumberOfExamples().isAtLeast(endIndex) == MetaDataInfo.NO) {
							createError(Severity.ERROR, Collections.singletonList(new ParameterSettingQuickFix(operator, endParameter, (emd.getNumberOfExamples().getValue()) + "")), "exampleset.parameter_value_exceeds_exampleset_size", endParameter, endIndex + "");
						}
						if (startIndex > endIndex) {
							operator.addError(new SimpleProcessSetupError(Severity.ERROR, operator.getPortOwner(), Collections.singletonList(new ParameterSettingQuickFix(operator, endParameter, (startIndex + 1) + "")), "parameter_combination_forbidden", startParameter, endParameter));

						}
					}
				} catch (Exception e) {
				}
			} else {
				inputPort.addError(new MetaDataUnderspecifiedError(inputPort));
			}
		}
	}

	@Override
	public void assumeSatisfied() {
		getInputPort().receiveMD(new ExampleSetMetaData());
	}

	@Override
	public String getDescription() {
		return "<em>expects:</em> ExampleSet";
	}

	@Override
	public boolean isCompatible(MetaData input, CompatibilityLevel level) {
		return ExampleSet.class.isAssignableFrom(input.getObjectClass());
	}

	@Override
	public MetaData getExpectedMetaData() {
		return new ExampleSetMetaData();
	}
}