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A library for core classes (Graph, Vertex, Edge, etc.)
There is a newer version: 2.11.0
package io.konig.cadl;

/*
 * #%L
 * Konig Core
 * %%
 * Copyright (C) 2015 - 2019 Gregory McFall
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */


import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.openrdf.model.URI;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import io.konig.core.impl.RdfUtil;
import io.konig.core.showl.ShowlClass;
import io.konig.core.showl.ShowlManager;

/**
 * A reasoner that sets properties of the cube based on heuristics.
 * The reasoner performs two functions:
 * 
 *    Set formulas for dimensions, levels and attributes.
 *   
 Define the rollUpTo relationships between levels
 * 
 * 
 * The reasoner uses the heuristic rules described below.
 * In these descriptions, ?source denotes the variable used
 * for a cadl:source of the Cube.
 * 
 * 
 *    
 *   	If the local name source is case-insenstive-equal to the local name of 
 *      a unique owl:Class, then that owl:Class is set as the `cadl:valueType`
 *      of the source.
 *   
 *   
 *      If the local name of a Dimension ends with the suffix "Dim" (e.g. "accountDim"), then let
 *      let dimName be the part of the name preceding the suffix (e.g. "account").  Otherwise, let
 *      dimName be the entire local name of the Dimension. If dimName uniquely matches the local name of 
 *      a property of ?source, then the formula for the dimension has the form: ?source.{dimName}
 *   
 *   
 *       If the local name of a Level is equal to the dimName value for the declaring
 *       Dimension, then the formula for the Level is identical to the formula for the Dimension.
 *   
 *   
 *       Let levelB be some Level.  If the local name of levelB uniquely matches the local name of 
 *       a property of a preceding Level (call it levelA), then
 *       
 *       	
 *       		The formula of the levelB is given by {formula-of-levelA}.{local-name-of-levelB}
 *       	
 *           The relationship, levelA cadl:rolesUpTo levelB is asserted.
 *       
 *   
 *   
 *   	Let attrName be the local name of an Attribute.  If attrName uniquely matches the local name
 *      of a property of the declaring Level, then the formula for the Attribute shall be given by
 *      {levelFormula}.{attrName}
 *   
 *   
 *      Let dim be a Dimension whose rdf:type is xsd:dateTime.  Then the following rules apply.
 *      
 *         
 *            If the name of a Level is case-insensitive-equal to a time unit (such as "DAY"),
 *            then the formula for the Level is given by: DATE_TRUNC({levelName}, {formula-of-dim})
 *        
 *         
 *            The levels of dim shall be sorted by granularity and roll-up relationships established
 *            based on that order.
 *        
 *      
 *   
 * 
 * @author Greg McFall
 *
 */
public class CubeReasoner {
	private static Logger logger = LoggerFactory.getLogger(CubeReasoner.class);
	private ShowlManager showlManager;
	private Map> classesByLocalName;
	
	
	
	public CubeReasoner(ShowlManager classManager) {
		this.showlManager = classManager;
	}

	public void visit(Cube cube) {
		buildMap();
		setSourceType(cube);
	}

	private void setSourceType(Cube cube) {
		
		if (cube.getSource().getValueType() == null) {
			Variable source = cube.getSource();
			URI sourceId = source.getId();
			if (sourceId != null) {
				String key = sourceId.getLocalName().toLowerCase();
				Set set = classesByLocalName.get(key);
				if (set != null && set.size()==1) {
					URI classId = set.iterator().next().getId();
					source.setValueType(classId);
					if (logger.isTraceEnabled()) {
						logger.trace(
							"setSourceType - Set {} as Value Type of {}", 
							curie(classId), sourceId);
					}
				}
			}
		}
		
	}

	private Object curie(URI id) {
		return RdfUtil.optionalCurie(showlManager.getReasoner().getGraph().getNamespaceManager(), id);
	}

	private void buildMap() {
		if (classesByLocalName == null) {
			classesByLocalName = new HashMap<>();
			for (ShowlClass owlClass : showlManager.listClasses()) {
				URI classId = owlClass.getId();
				String key = classId.getLocalName().toLowerCase();
				
				Set set = classesByLocalName.get(key);
				if (set == null) {
					set = new HashSet<>();
					classesByLocalName.put(key, set);
				}
				set.add(owlClass);
			}
		}
		
	}

}