package net.wotonomy.test;

import net.wotonomy.control.EOClassDescription;
import net.wotonomy.control.EODataSource;
import net.wotonomy.control.EOEditingContext;
import net.wotonomy.control.EOFetchSpecification;
import net.wotonomy.foundation.NSArray;

/**
* A custom DataSource that works with 
* the datastore package for persistence.
*/
public class TestDataSource extends EODataSource
{
    private EOEditingContext context;
    private Object source;
    private String key;
    
	public TestDataSource()
	{
        this( Test.editingContext );
	}
    
	public TestDataSource( EOEditingContext aContext )
	{
        context = aContext;
	}
    
    public EOEditingContext editingContext()
    {
        return context;
    }
	
    /**
    * This implementation does nothing.
    */
    public void insertObject ( Object anObject )
	{
        // creates are handled by createObject().
	}

    /**
    * Deletes the specified object from this data source.
    */
    public void deleteObject ( Object anObject )
	{
        editingContext().deleteObject( anObject );
	}

    /**
    * Returns a List containing the objects in this
    * data source.  This implementation returns all
	* TestObjects that have been persisted to the 
	* datastore in the data directory.
    */
    public NSArray fetchObjects ()
    {
        if ( source == null )
        {
            NSArray result = editingContext().objectsWithFetchSpecification( 
                new EOFetchSpecification() );
            if ( result.size() > 0 )
            {
                result = new NSArray( result.objectAtIndex( 0 ) );
//result.add( result.objectAtIndex( 0 ) );
            }
            return result;
        }
        else
        {
            return new NSArray( 
                ((TestObject)source).getChildList() );
        }
    }

    /**
    * Returns a data source that is capable of
    * manipulating objects of the type returned by 
    * applying the specified key to objects 
    * vended by this data source.
    * @see #qualifyWithRelationshipKey
    */
    public EODataSource 
        dataSourceQualifiedByKey ( String aKey )
	{
		return new TestDataSource( editingContext() );	
	}

    /**
    * Restricts this data source to vend those 
    * objects that are associated with the specified 
    * key on the specified object.
    */
    public void 
        qualifyWithRelationshipKey ( 
        String aKey, Object anObject )
	{
        key = aKey;
        source = anObject;
	}

    /**
    * Returns the description of the class of the
    * objects that is vended by this data source,
    * or null if this cannot be determined.
	* This implementation returns TestObject.
    */
    public EOClassDescription 
        classDescriptionForObjects ()
    {
        return EOClassDescription.classDescriptionForClass( 
                        TestObject.class );
    }

}