/*
 * Created on Dec 28, 2004
 */
package impl.swrl;

import java.util.HashSet;
import java.util.Set;

import org.mindswap.exceptions.NotImplementedException;
import org.mindswap.owl.OWLIndividual;
import org.mindswap.owl.OWLValue;
import org.mindswap.owl.list.RDFList;
import org.mindswap.owl.vocabulary.RDF;
import org.mindswap.owl.vocabulary.SWRL;
import org.mindswap.owl.vocabulary.SWRLB;
import org.mindswap.query.ValueMap;
import org.mindswap.swrl.BuiltinAtom;
import org.mindswap.swrl.SWRLDataObject;
import org.mindswap.swrl.SWRLObject;

/**
 * @author Evren Sirin
 *
 */
public class BuiltinAtomImpl extends AtomImpl implements BuiltinAtom {
    private final static Set THREE_ARGS = new HashSet();
    static {
        THREE_ARGS.add( SWRLB.add );
        THREE_ARGS.add( SWRLB.subtract );
        THREE_ARGS.add( SWRLB.multiply );
        THREE_ARGS.add( SWRLB.divide );        
    }
    
    public BuiltinAtomImpl(OWLIndividual ind) {
        super(ind);
    }

    public OWLIndividual getBuiltin() {
        return getProperty(SWRL.builtin);
    }
    
    public void setBuiltin(OWLIndividual builtin) {
        setProperty(SWRL.builtin, builtin);
    }
        
    public int getArgumentCount() {
        if( THREE_ARGS.contains( getBuiltin() ) )
            return 3;
        
        return 2;
    }
    
    private RDFList getArguments() {
       OWLIndividual args = getProperty(SWRL.arguments);
       
       return (args == null) ? null : (RDFList) args.castTo( RDFList.class ); 
    }

    public SWRLObject getArgument( int index ) {
        RDFList args = getArguments();
        
        if( args == null ) return null;
        
        OWLValue arg = args.getValue( index );

        if( arg == null ) return null;

        return (SWRLDataObject) arg.castTo( SWRLDataObject.class );
    }    
    
    public void addArgument( SWRLObject arg ) {
        if(!(arg instanceof SWRLDataObject))
            throw new IllegalArgumentException("BuiltinAtom argument should be a SWRLDataObject");
        
        RDFList args = getArguments();
        
        if( args == null ) {
            RDFList nil = getOntology().createList( RDF.ListVocabulary );
            args = nil.insert( arg );
            setProperty(SWRL.arguments, args);
        }
        else 
            args.add( arg );        
    }

    public void setArgument(int index, SWRLObject arg) {
        if(!(arg instanceof SWRLDataObject))
            throw new IllegalArgumentException("BuiltinAtom argument should be a SWRLDataObject");
        
        RDFList args = getArguments();
        
        if( args == null ) {
            if( index == 0 ) {
                RDFList nil = getOntology().createList( RDF.ListVocabulary );
                args = nil.insert( arg );
                setProperty(SWRL.arguments, args);
            }
            else
                throw new IndexOutOfBoundsException();
        }
        else {
            args.set( index, arg );
        }
    }  
    
    public String toString() {
        OWLIndividual builtin = getBuiltin();
        if(builtin == null)
            return "Missing_class_predicate";
        
        StringBuffer str = new StringBuffer();
        if( builtin.equals( SWRLB.equal ) ) {
            str.append( "(" );
            str.append( getArgument(0) );
            str.append( " = " );
            str.append( getArgument(1) );
            str.append( ")" );
        }
        else if( builtin.equals( SWRLB.lessThan ) ) {
            str.append( "(" );
            str.append( getArgument(0) );
            str.append( " < " );
            str.append( getArgument(1) );
            str.append( ")" );
        }
        else if( builtin.equals( SWRLB.greaterThan ) ) {
            str.append( "(" );
            str.append( getArgument(0) );
            str.append( " > " );
            str.append( getArgument(1) );
            str.append( ")" );
        }
        else if( builtin.equals( SWRLB.add ) ) {
            str.append( "(" );
            str.append( getArgument(0) );
            str.append( " = " );
            str.append( getArgument(1) );
            str.append( " + " );
            str.append( getArgument(2) );
            str.append( ")" );
        }
        else if( builtin.equals( SWRLB.subtract ) ) {
            str.append( "(" );
            str.append( getArgument(0) );
            str.append( " = " );
            str.append( getArgument(1) );
            str.append( " - " );
            str.append( getArgument(2) );
            str.append( ")" );
        }
        else {
	        str.append( builtin.getLocalName() ).append( "(" );
	        for(int i = 0; i < getArgumentCount(); i++) {
	            SWRLObject arg = getArgument( i );
	            if( i > 0 )
	                str.append( ", " );
	            str.append( arg );
	        }
	        str.append(")");
        }

        return str.toString();
    }

	public void evaluate(ValueMap values) {
		OWLIndividual builtin = getBuiltin();
		if (! (builtin.equals(SWRLB.add) || builtin.equals(SWRLB.subtract) ||
				builtin.equals(SWRLB.multiply) || builtin.equals(SWRLB.divide)))
			return;
		
		throw new NotImplementedException("Builtin SWRL atoms cannot be evaluated");
	}
}