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 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package jdk.nashorn.internal.ir;

import jdk.nashorn.internal.ir.annotations.Immutable;

import jdk.nashorn.internal.ir.visitor.NodeVisitor;

/**

 * TernaryNode nodes represent three operand operations (?:).

 */

@Immutable

public final class TernaryNode extends Expression {

    private final Expression test;

    private final Expression trueExpr;

    /** Third argument. */

    private final Expression falseExpr;

    /**

     * Constructor

     *

     * @param token     token

     * @param test      test expression

     * @param trueExpr  expression evaluated when test evaluates to true

     * @param falseExpr expression evaluated when test evaluates to true

     */

    public TernaryNode(final long token, final Expression test, final Expression trueExpr, final Expression falseExpr) {

        super(token, falseExpr.getFinish());

        this.test = test;

        this.trueExpr = trueExpr;

        this.falseExpr = falseExpr;

    }

    private TernaryNode(final TernaryNode ternaryNode, final Expression test, final Expression trueExpr, final Expression falseExpr) {

        super(ternaryNode);

        this.test = test;

        this.trueExpr = trueExpr;

        this.falseExpr = falseExpr;

    }

    @Override

    public Node accept(final NodeVisitor<? extends LexicalContext> visitor) {

        if (visitor.enterTernaryNode(this)) {

            final Expression newTest = (Expression)getTest().accept(visitor);

            final Expression newTrueExpr = (Expression)getTrueExpression().accept(visitor);

            final Expression newFalseExpr = (Expression)falseExpr.accept(visitor);

            return visitor.leaveTernaryNode(setTest(newTest).setTrueExpression(newTrueExpr).setFalseExpression1(newFalseExpr));

        }

        return this;

    }

    @Override

    public void toString(final StringBuilder sb) {

        final boolean testParen  = tokenType().needsParens(getTest().tokenType(), true);

        final boolean trueParen  = tokenType().needsParens(getTrueExpression().tokenType(), false);

        final boolean falseParen = tokenType().needsParens(getFalseExpression().tokenType(), false);

        if (testParen) {

            sb.append('(');

        }

        getTest().toString(sb);

        if (testParen) {

            sb.append(')');

        }

        sb.append(" ? ");

        if (trueParen) {

            sb.append('(');

        }

        getTrueExpression().toString(sb);

        if (trueParen) {

            sb.append(')');

        }

        sb.append(" : ");

        if (falseParen) {

            sb.append('(');

        }

        getFalseExpression().toString(sb);

        if (falseParen) {

            sb.append(')');

        }

    }

    /**

     * Get the test expression for this ternary expression, i.e. "x" in x ? y : z

     * @return the test expression

     */

    public Expression getTest() {

        return test;

    }

    /**

     * Get the true expression for this ternary expression, i.e. "y" in x ? y : z

     * @return the true expression

     */

    public Expression getTrueExpression() {

        return trueExpr;

    }

    /**

     * Get the false expression for this ternary expression, i.e. "z" in x ? y : z

     * @return the false expression

     */

    public Expression getFalseExpression() {

        return falseExpr;

    }

    /**

     * Set the test expression for this node

     * @param test new test expression

     * @return a node equivalent to this one except for the requested change.

     */

    public TernaryNode setTest(final Expression test) {

        if (this.test == test) {

            return this;

        }

        return new TernaryNode(this, test, trueExpr, falseExpr);

    }

    /**

     * Set the true expression for this node

     * @param trueExpr new true expression

     * @return a node equivalent to this one except for the requested change.

     */

    public TernaryNode setTrueExpression(final Expression trueExpr) {

        if (this.trueExpr == trueExpr) {

            return this;

        }

        return new TernaryNode(this, test, trueExpr, falseExpr);

    }

    /**

     * Set the false expression for this node

     * @param falseExpr new false expression

     * @return a node equivalent to this one except for the requested change.

     */

    public TernaryNode setFalseExpression1(final Expression falseExpr) {

        if (this.falseExpr == falseExpr) {

            return this;

        }

        return new TernaryNode(this, test, trueExpr, falseExpr);

    }

}