package org.sat4j.csp.xml;
   import org.xml.sax.Attributes;
   
   import static org.sat4j.csp.xml.TagNames.*;
   
   class Relation extends Element {
   
   
   	private StringBuilder allTuples;
  
  	public Relation(ICSPCallback out,String tagName) {
  		super(out,tagName);
  	}
  
  	public void startElement(Attributes att) {
  		int nbTuples = -1;
  		String tmpTuples = att.getValue(NB_TUPLES);
  		if (tmpTuples != null)
  			nbTuples = Integer.parseInt(tmpTuples);
  		String semantics = att.getValue(SEMANTICS);
  		boolean isSupport = (semantics != null && semantics.equals(SUPPORT));
  		int arity = Integer.parseInt(att.getValue(ARITY));
  		getCB().beginRelation(att.getValue(NAME), arity, nbTuples, isSupport);
  		// reinitialization of the string for the tuples
  		allTuples = new StringBuilder();
  	}
  
  	public void characters(String allTuples) {
  		this.allTuples.append(allTuples);
  	}
  
  	public void endElement() {
  		String[] tuples = allTuples.toString().trim().split(TUPLE_SEPARATOR);
  		int[] oneTuple;
  		for (String tuple : tuples) {
  			if (!tuple.equals("")) {
  				oneTuple = toIntArray(tuple.split("\\s+"));
  				// is the following OK?
  //				if (oneTuple.length != arity)
  //					throw new CSPFormatException("At least one tuple doesn't have the right arity.");
  				getCB().addRelationTuple(oneTuple);
  			}
  		}
  		getCB().endRelation();
  	}
  
  	private int[] toIntArray(String[] str) {
  		int[] res = new int[str.length];
  		for (int i = 0; i < str.length; i++)
  			res[i] = Integer.parseInt(str[i]);
  		return res;
  	}
  
  }