org.eclipse.rmf.reqif10.search/src/org/eclipse/rmf/reqif10/search/filter/NumberFilter.java

/*******************************************************************************
 * Copyright (c) 2014 Formal Mind GmbH.
 * 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     Ingo Weigelt - initial API and implementation
 ******************************************************************************/
package org.eclipse.rmf.reqif10.search.filter;

import java.math.BigInteger;

import org.eclipse.rmf.reqif10.AttributeDefinition;
import org.eclipse.rmf.reqif10.AttributeDefinitionInteger;
import org.eclipse.rmf.reqif10.AttributeDefinitionReal;
import org.eclipse.rmf.reqif10.AttributeValueInteger;
import org.eclipse.rmf.reqif10.AttributeValueReal;
import org.eclipse.rmf.reqif10.SpecElementWithAttributes;
import org.eclipse.rmf.reqif10.common.util.ReqIF10Util;

import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Sets;

public class NumberFilter extends AbstractAttributeFilter {

	public static final ImmutableSet<Operator> SUPPORTED_OPERATORS = Sets
			.immutableEnumSet(Operator.IS, Operator.IS_NOT,
					Operator.BETWEEN, Operator.GREATER, Operator.SMALLER, Operator.IS_SET, Operator.IS_NOT_SET);
	
	private AttributeDefinition attributeDefinition;

	private Operator operator;
	private Comparable<Number> value1;
	private Comparable<Number> value2;
	
	
	
	public NumberFilter(Operator operator, BigInteger value1, BigInteger value2, 
			AttributeDefinitionInteger attributeDefinition) {
		init(operator, value1, value2, attributeDefinition);
	}
	
	public NumberFilter(Operator operator, Double value1, Double value2, 
			AttributeDefinitionReal attributeDefinition) {
		init(operator, value1, value2, attributeDefinition);
	}

	/**
	 * TODO (mj) How about abandoning the above two constructors in favor of
	 * this one? Maybe after adding some sanity checks.
	 */
	public NumberFilter(Operator operator, Number value1, Number value2,
			AttributeDefinition attributeDefinition) {
		
		init(operator, (Comparable<? extends Number>) value1,
				(Comparable<? extends Number>) value2, attributeDefinition);
	}
	
	/**
	 * 
	 * @param operator 
	 * @param value1 the value used for all operations. For the BETWEEN operation this is the lower value
	 * @param value2 If operation is BETWEEN, this is the upper bound. Otherwise this parameter is ignored
	 * @param attributeDefinition
	 */
	@SuppressWarnings("unchecked")
	private void init(Operator operator, Comparable<? extends Number> value1, Comparable<? extends Number> value2, 
			AttributeDefinition attributeDefinition) {
		
		// ensure that operator is supported
		if (!SUPPORTED_OPERATORS.contains(operator)){
				throw new IllegalArgumentException(
						"This filter does not support the " + operator.toString()
								+ " operation");
		};
		
		// ensure that value1 is not null
		if (null == value1 && operator != Operator.IS_SET && operator != Operator.IS_NOT_SET  ){
			throw new IllegalArgumentException(
					"value1 can not be null");
		}
		
		// ensure that value2 is not null for operations that need two parameters
		if (operator.equals(IFilter.Operator.BETWEEN)) {
			if (null == value2) {
				throw new IllegalArgumentException("value2 can not be null");
			}
		}
		
		
		this.attributeDefinition = attributeDefinition;
		this.operator = operator;
		this.value1 =  (Comparable<Number>) value1;
		this.value2 =  (Comparable<Number>) value2;
	}
	


	@Override
	public boolean match(SpecElementWithAttributes element) {
		if (operator == Operator.IS_SET || operator == Operator.IS_NOT_SET){
			return super.match(element);
		}
		
		
		Number theValue = getTheValue(element);
		
		
		if (theValue == null){
			/* Check if there is any default value for this attribute */
			theValue = getDefaultValue(element);
		}
		
		
		if (theValue == null){
			if (operator.equals(Operator.IS_NOT)){
				return true;
			}
			return false;
		}
	
		
		switch (operator) {
		case IS:
			return value1.compareTo(theValue) == 0;
		case IS_NOT:
			return value1.compareTo(theValue) != 0;
		case BETWEEN:
			return value1.compareTo(theValue) <= 0 && value2.compareTo(theValue) >= 0;
		case GREATER:
			return value1.compareTo(theValue) <= 0;
		case SMALLER:
			return value1.compareTo(theValue) >= 0;
			
		default:
			throw new IllegalArgumentException(
					"This filter does not support the " + this.operator
							+ " operation");
		}
		
	}
	
	private Number getDefaultValue(SpecElementWithAttributes element) {
		if (!AbstractAttributeFilter.isSetAttribute(element, attributeDefinition)){
			return null;
		}
		
		if (attributeDefinition instanceof AttributeDefinitionInteger) {
			AttributeDefinitionInteger ad = (AttributeDefinitionInteger) attributeDefinition;
			if (!ad.isSetDefaultValue()){
				return null;
			}
			if (!ad.getDefaultValue().isSetTheValue()){
				return null;
			}
			return ad.getDefaultValue().getTheValue(); 
		}
		if (attributeDefinition instanceof AttributeDefinitionReal) {
			AttributeDefinitionReal ad = (AttributeDefinitionReal) attributeDefinition;
			if (!ad.isSetDefaultValue()){
				return null;
			}
			if (!ad.getDefaultValue().isSetTheValue()){
				return null;
			}
			return ad.getDefaultValue().getTheValue();
		}
		throw new IllegalStateException("Expected an AttributeDefinitionInteger or AttributeDefinitionReal as attribute but found " + attributeDefinition.getClass());
	}

	private Number getTheValue(SpecElementWithAttributes element){
		if (attributeDefinition instanceof AttributeDefinitionInteger){
			AttributeValueInteger attributeValue = (AttributeValueInteger) ReqIF10Util.getAttributeValue(element, attributeDefinition);
			if (attributeValue == null || !attributeValue.isSetTheValue()){
				return null;
			}
			return attributeValue.getTheValue();
		}
		if (attributeDefinition instanceof AttributeDefinitionReal){
			AttributeValueReal attributeValue = (AttributeValueReal) ReqIF10Util.getAttributeValue(element, attributeDefinition);
			if (attributeValue == null || !attributeValue.isSetTheValue()){
				return null;
			}
			return attributeValue.getTheValue();
		}
		else{
			throw new IllegalArgumentException("SpecElementType is not supported");
		}
	}

	@Override
	public AttributeDefinition getAttribute() {
		return attributeDefinition;
	}

	@Override
	public Operator getOperator() {
		return operator;
	}

	@Override
	public Number getFilterValue1() {
		return (Number) value1;
	}

	@Override
	public Number getFilterValue2() {
		return (Number) value2;
	}

	@Override
	public ImmutableSet<Operator> getSupportedOperators() {
		return SUPPORTED_OPERATORS;
	}
	
	

}