/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2014, Red Hat Inc. or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.hql.internal.ast.tree;

import org.hibernate.QueryException;
import org.hibernate.dialect.function.CastFunction;
import org.hibernate.dialect.function.SQLFunction;
import org.hibernate.hql.internal.ast.util.ColumnHelper;
import org.hibernate.type.Type;

import antlr.SemanticException;

Represents a cast function call.  We handle this specially because its type
argument has a semantic meaning to the HQL query (its not just pass through).
Author:
Steve Ebersole/**
 * Represents a cast function call.  We handle this specially because its type
 * argument has a semantic meaning to the HQL query (its not just pass through).
 *
 * @author Steve Ebersole
 */
public class CastFunctionNode extends AbstractSelectExpression implements FunctionNode {
	private SQLFunction dialectCastFunction;

	private Node expressionNode;

	private IdentNode typeNode;
	private Type castType;


	
Called from the hql-sql grammar after the children of the CAST have been resolved.
Params:
inSelect – Is this call part of the SELECT clause?/**
	 * Called from the hql-sql grammar after the children of the CAST have been resolved.
	 *
	 * @param inSelect Is this call part of the SELECT clause?
	 */
	public void resolve(boolean inSelect) {
		this.dialectCastFunction = getSessionFactoryHelper().findSQLFunction( "cast" );
		if ( dialectCastFunction == null ) {
			dialectCastFunction = CastFunction.INSTANCE;
		}

		this.expressionNode = (Node) getFirstChild();
		if ( expressionNode == null ) {
			throw new QueryException( "Could not resolve expression to CAST" );
		}
		if ( SqlNode.class.isInstance( expressionNode ) ) {
			final Type expressionType = ( (SqlNode) expressionNode ).getDataType();
			if ( expressionType != null ) {
				if ( expressionType.isEntityType() ) {
					throw new QueryException( "Expression to CAST cannot be an entity : " + expressionNode.getText() );
				}
				if ( expressionType.isComponentType() ) {
					throw new QueryException( "Expression to CAST cannot be a composite : " + expressionNode.getText() );
				}
				if ( expressionType.isCollectionType() ) {
					throw new QueryException( "Expression to CAST cannot be a collection : " + expressionNode.getText() );
				}
			}
		}

		this.typeNode = (IdentNode) expressionNode.getNextSibling();
		if ( typeNode == null ) {
			throw new QueryException( "Could not resolve requested type for CAST" );
		}

		final String typeName = typeNode.getText();
		this.castType = getSessionFactoryHelper().getFactory().getTypeResolver().heuristicType( typeName );
		if ( castType == null ) {
			throw new QueryException( "Could not resolve requested type for CAST : " + typeName );
		}
		if ( castType.isEntityType() ) {
			throw new QueryException( "CAST target type cannot be an entity : " + expressionNode.getText() );
		}
		if ( castType.isComponentType() ) {
			throw new QueryException( "CAST target type cannot be a composite : " + expressionNode.getText() );
		}
		if ( castType.isCollectionType() ) {
			throw new QueryException( "CAST target type cannot be a collection : " + expressionNode.getText() );
		}
		setDataType( castType );
	}

	@Override
	public SQLFunction getSQLFunction() {
		return dialectCastFunction;
	}

	@Override
	public Type getFirstArgumentType() {
		return castType;
	}

	@Override
	public void setScalarColumnText(int i) throws SemanticException {
		ColumnHelper.generateSingleScalarColumn( this, i );
	}
}