package org.drools.reteoo;

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

import org.drools.FactHandle;
import org.drools.NoSuchFactObjectException;
import org.drools.WorkingMemory;
import org.drools.spi.ClassObjectType;
import org.drools.spi.Constraint;
import org.drools.spi.Tuple;

public class BetaNodeBinder
{
    private final Constraint[]  constraints;    
    
    public BetaNodeBinder( )
    {
        this.constraints = null;
    }
    
    public BetaNodeBinder( Constraint constraint )
    {
        this.constraints = new Constraint[] { constraint }; 
    }    
    
    public BetaNodeBinder( Constraint[] constraints )
    {
        this.constraints = constraints;
    }
    
    boolean isAllowed(Object object,
                      FactHandle handle,                      
                      Tuple tuple,
                      WorkingMemory workingMemory)
    {
        if ( constraints == null )
        {
            return true;
        }
         
        for (int i=0; i < this.constraints.length; i++)
        {
        	if ( ! this.constraints[i].isAllowed( object,
                                   		    	  handle,
                    				              tuple ) )
        	{
        		return false;
        	}
        }
        
        return true;
        
    }
    
    boolean isAllowed(FactHandle handle,                      
                      Tuple tuple,
                      WorkingMemory workingMemory)
    {
    	Object object = workingMemory.getObject( handle );
    	
    	return isAllowed(object, handle, tuple, workingMemory);
    }    
    
    public Set getRequiredDeclarations()
    {
        Set declarations = new HashSet();
        for ( int i = 0; i < this.constraints.length; i++ )
        {
           Collections.addAll(declarations, this.constraints[i].getRequiredDeclarations()); 
        }
        return declarations;
    }
    
    public int hashCode()
    {
        return this.constraints.hashCode();
    }
    
    /**
     * Determine if another object is equal to this.
     *
     * @param object The object to test.
     *
     * @return <code>true</code> if <code>object</code> is equal to this,
     *         otherwise <code>false</code>.
     */
    public boolean equals( Object object )
    {
        if ( this == object )
        {
            return true;
        }

        if ( object == null || getClass( ) != object.getClass( ) )
        {
            return false;
        }
        
        BetaNodeBinder other = ( BetaNodeBinder ) object;
        
        if ( this.constraints.length != other.constraints.length )
        {
            return false;
        }

        for (int i=0; i < this.constraints.length; i++)
        {
            if ( ! this.constraints[i].equals( other.constraints[i] ) )
            {
                return false;
            }
        }        

        return true;
    } 

}