/*
 ***** BEGIN LICENSE BLOCK *****
 * Version: CPL 1.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Common Public
 * License Version 1.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.eclipse.org/legal/cpl-v10.html
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * Copyright (C) 2001-2002 Jan Arne Petersen <jpetersen@uni-bonn.de>
 * Copyright (C) 2001-2002 Benoit Cerrina <b.cerrina@wanadoo.fr>
 * Copyright (C) 2002-2004 Anders Bengtsson <ndrsbngtssn@yahoo.se>
 * Copyright (C) 2004 Thomas E Enebo <enebo@acm.org>
 * 
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the CPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the CPL, the GPL or the LGPL.
 ***** END LICENSE BLOCK *****/
package org.jruby.ast;

import java.util.List;

import org.jruby.Ruby;
import org.jruby.RubyArray;
import org.jruby.ast.visitor.NodeVisitor;
import org.jruby.javasupport.util.RuntimeHelpers;
import org.jruby.lexer.yacc.ISourcePosition;
import org.jruby.runtime.Block;
import org.jruby.runtime.CallSite;
import org.jruby.runtime.MethodIndex;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.builtin.IRubyObject;

/**
 * Represents a when condition
 */
public class WhenNode extends Node {
    protected final Node expressionNodes;
    protected final Node bodyNode;
    private final Node nextCase;
    public final CallSite eqq = MethodIndex.getFunctionalCallSite("===");

    public WhenNode(ISourcePosition position, Node expressionNodes, Node bodyNode, Node nextCase) {
        super(position);
        this.expressionNodes = expressionNodes;
        if (expressionNodes instanceof ArrayNode) {
            ((ArrayNode)expressionNodes).setLightweight(true);
        }

        assert bodyNode != null : "bodyNode is not null";
        
        this.bodyNode = bodyNode;
        this.nextCase = nextCase;
    }

    public NodeType getNodeType() {
        return NodeType.WHENNODE;
    }

    /**
     * Accept for the visitor pattern.
     * @param iVisitor the visitor
     **/
    public Object accept(NodeVisitor iVisitor) {
        return iVisitor.visitWhenNode(this);
    }

    /**
     * Gets the bodyNode.
     * @return Returns a INode
     */
    public Node getBodyNode() {
        return bodyNode;
    }
    
    /**
     * Gets the next case node (if any).
     */
    public Node getNextCase() {
        return nextCase;
    }

    /**
     * Get the expressionNode(s).
     */
    public Node getExpressionNodes() {
        return expressionNodes;
    }

    public List<Node> childNodes() {
        return Node.createList(expressionNodes, bodyNode, nextCase);
    }
    
    @Override
    public IRubyObject interpret(Ruby runtime, ThreadContext context, IRubyObject self, Block aBlock) {
        return bodyNode.interpret(runtime, context, self, aBlock);
    }

    public IRubyObject when(IRubyObject value, ThreadContext context, Ruby runtime, IRubyObject self, Block aBlock) {
        RubyArray expressions = RuntimeHelpers.splatValue(expressionNodes.interpret(runtime, context, self, aBlock));

        for (int j = 0,k = expressions.getLength(); j < k; j++) {
            IRubyObject test = expressions.eltInternal(j);

            if ((value != null && eqq.call(context, self, test, value).isTrue())
                    || (value == null && test.isTrue())) {
                return bodyNode.interpret(runtime, context, self, aBlock);
            }
        }

        return null;
    }
}
