/*
 *  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.preprocessing.transformation.aggregation;

import com.rapidminer.operator.ProcessSetupError.Severity;
import com.rapidminer.operator.ports.InputPort;
import com.rapidminer.operator.ports.metadata.AttributeMetaData;
import com.rapidminer.operator.ports.metadata.SimpleMetaDataError;
import com.rapidminer.tools.Ontology;

/**
 * This class offers an implementation of {@link AggregationFunctionMetaDataProvider} interface and can be
 * parameterized to work for several {@link AggregationFunction}s on instanciation.
 * 
 * @author Sebastian Land
 */
public class DefaultAggregationFunctionMetaDataProvider implements AggregationFunctionMetaDataProvider {

    private boolean copyValueType = false;
    private int matchingValueTypes[];
    private int resultValueType;
    private String aggregationFunctionName;
    private String functionName;
    private String separatorOpen;
    private String separatorClose;

    public DefaultAggregationFunctionMetaDataProvider(String aggregationFunctionName, String functionName, String separatorOpen, String separatorClose, int matchingValueTypes[]) {
        this(aggregationFunctionName, functionName, separatorOpen, separatorClose, matchingValueTypes, 0);
        this.copyValueType = true;
    }

    public DefaultAggregationFunctionMetaDataProvider(String aggregationFunctionName, String functionName, String separatorOpen, String separatorClose, int matchingValueTypes[], int resultValueType) {
        this.aggregationFunctionName = aggregationFunctionName;
        this.functionName = functionName;
        this.separatorClose = separatorClose;
        this.separatorOpen = separatorOpen;
        this.matchingValueTypes = matchingValueTypes;
        this.resultValueType = resultValueType;
    }

    @Override
    public AttributeMetaData getTargetAttributeMetaData(AttributeMetaData sourceAttribute, InputPort port) {
    	boolean matches = false;
    	for (int type : matchingValueTypes) {
    		matches |= Ontology.ATTRIBUTE_VALUE_TYPE.isA(sourceAttribute.getValueType(), type);
    	}
        if (matches || sourceAttribute.getValueType() == Ontology.ATTRIBUTE_VALUE) {
            if (copyValueType)
                return new AttributeMetaData(functionName + separatorOpen + sourceAttribute.getName() + separatorClose, sourceAttribute.getValueType());
            else
                return new AttributeMetaData(functionName + separatorOpen + sourceAttribute.getName() + separatorClose, resultValueType);
        } else {
            // not matching type: Return null and register error
        	if (matchingValueTypes.length == 1) {
        		port.addError(new SimpleMetaDataError(Severity.ERROR, port, "aggregation.incompatible_value_type", 
        				sourceAttribute.getName(), 
        				aggregationFunctionName, 
        				Ontology.VALUE_TYPE_NAMES[sourceAttribute.getValueType()], 
        				Ontology.VALUE_TYPE_NAMES[matchingValueTypes[0]]));
        	} else {
        		boolean first = true;
        		StringBuilder b = new StringBuilder();
        		for (int i = 0; i < matchingValueTypes.length-1; i++) {
        			if (first) {
        				first = false;
        			} else {
        				b.append(", ");
        			}
        			b.append(Ontology.VALUE_TYPE_NAMES[matchingValueTypes[i]]);
        		}
        		port.addError(new SimpleMetaDataError(Severity.ERROR, port, "aggregation.incompatible_value_type_multiple", 
        				sourceAttribute.getName(), 
        				aggregationFunctionName, 
        				Ontology.VALUE_TYPE_NAMES[sourceAttribute.getValueType()],
        				b.toString(),
        				Ontology.VALUE_TYPE_NAMES[matchingValueTypes[matchingValueTypes.length - 1]]));
        	}
            return null;
        }
    }

}