//--------------------------------------------------------------------------
//	Copyright (c) 1998-2004, Drew Davidson and Luke Blanshard
//  All rights reserved.
//
//	Redistribution and use in source and binary forms, with or without
//  modification, are permitted provided that the following conditions are
//  met:
//
//	Redistributions of source code must retain the above copyright notice,
//  this list of conditions and the following disclaimer.
//	Redistributions in binary form must reproduce the above copyright
//  notice, this list of conditions and the following disclaimer in the
//  documentation and/or other materials provided with the distribution.
//	Neither the name of the Drew Davidson nor the names of its contributors
//  may be used to endorse or promote products derived from this software
//  without specific prior written permission.
//
//	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
//  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
//  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
//  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
//  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
//  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
//  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
//  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
//  AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
//  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
//  THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
//  DAMAGE.
//--------------------------------------------------------------------------
package ariba.util.expr;

import ariba.util.core.ArrayUtil;

/**
 * @author Luke Blanshard (blanshlu@netscape.net)
 * @author Drew Davidson (drew@ognl.org)
 */
class ASTEval extends SimpleNode
{
    public ASTEval(int id) {
        super(id);
    }

    public ASTEval(ExprParser p, int id) {
        super(p, id);
    }

    protected Object getValueBody( ExprContext context, Object source ) throws ExprException
    {
        Object  result,
                expr = children[0].getValue( context, source ),
                previousRoot = context.getRoot();
        Node    node;

        source = children[1].getValue( context, source );
        node = (expr instanceof Node) ? (Node) expr : (Node) Expr.parseExpression( expr.toString() );
        try {
            context.setRoot( source );
            result = node.getValue( context, source );
        } finally {
            context.setRoot( previousRoot );
        }
        return result;
    }

    protected void setValueBody( ExprContext context, Object target, Object value ) throws ExprException
    {
        Object  expr = children[0].getValue(context, target),
                previousRoot = context.getRoot();
        Node    node;

        target = children[1].getValue( context, target );
        node = (expr instanceof Node) ? (Node) expr : (Node) Expr.parseExpression( expr.toString() );
        try {
            context.setRoot( target );
            node.setValue( context, target, value );
        } finally {
            context.setRoot( previousRoot );
        }
    }

    public String toString()
    {
        return "(" + children[0] + ")(" + children[1] + ")";
    }

    public void accept (ASTNodeVisitor visitor)
    {
        // The context of the right sub-expression (children[0]) is derived
        // from the context of the left sub-expression (children[1]).  So it
        // need to navigate the children[1] first.

        children[1].accept(visitor);
        visitor.visit(this);
        children[0].accept(visitor);
    }
}