/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

package org.mozilla.javascript.ast;

import org.mozilla.javascript.Token;

/**
 * C-style for-loop statement.
 * Node type is {@link Token#FOR}.<p>
 *
 * <pre><b>for</b> ( ExpressionNoInopt; Expressionopt ; Expressionopt ) Statement</pre>
 * <pre><b>for</b> ( <b>var</b> VariableDeclarationListNoIn; Expressionopt ; Expressionopt ) Statement</pre>
 */
public class ForLoop extends Loop {

    private AstNode initializer;
    private AstNode condition;
    private AstNode increment;

    {
        type = Token.FOR;
    }

    public ForLoop() {
    }

    public ForLoop(int pos) {
        super(pos);
    }

    public ForLoop(int pos, int len) {
        super(pos, len);
    }

    /**
     * Returns loop initializer variable declaration list.
     * This is either a {@link VariableDeclaration}, an
     * {@link Assignment}, or an {@link InfixExpression} of
     * type COMMA that chains multiple variable assignments.
     */
    public AstNode getInitializer() {
        return initializer;
    }

    /**
     * Sets loop initializer expression, and sets its parent
     * to this node.  Virtually any expression can be in the initializer,
     * so no error-checking is done other than a {@code null}-check.
     * @param initializer loop initializer.  Pass an
     * {@link EmptyExpression} if the initializer is not specified.
     * @throws IllegalArgumentException if condition is {@code null}
     */
    public void setInitializer(AstNode initializer) {
        assertNotNull(initializer);
        this.initializer = initializer;
        initializer.setParent(this);
    }

    /**
     * Returns loop condition
     */
    public AstNode getCondition() {
        return condition;
    }

    /**
     * Sets loop condition, and sets its parent to this node.
     * @param condition loop condition.  Pass an {@link EmptyExpression}
     * if the condition is missing.
     * @throws IllegalArgumentException} if condition is {@code null}
     */
    public void setCondition(AstNode condition) {
        assertNotNull(condition);
        this.condition = condition;
        condition.setParent(this);
    }

    /**
     * Returns loop increment expression
     */
    public AstNode getIncrement() {
        return increment;
    }

    /**
     * Sets loop increment expression, and sets its parent to
     * this node.
     * @param increment loop increment expression.  Pass an
     * {@link EmptyExpression} if increment is {@code null}.
     * @throws IllegalArgumentException} if increment is {@code null}
     */
    public void setIncrement(AstNode increment) {
        assertNotNull(increment);
        this.increment = increment;
        increment.setParent(this);
    }

    @Override
    public String toSource(int depth) {
        StringBuilder sb = new StringBuilder();
        sb.append(makeIndent(depth));
        sb.append("for (");
        sb.append(initializer.toSource(0));
        sb.append("; ");
        sb.append(condition.toSource(0));
        sb.append("; ");
        sb.append(increment.toSource(0));
        sb.append(") ");
        if (body.getType() == Token.BLOCK) {
            sb.append(body.toSource(depth).trim()).append("\n");
        } else {
            sb.append("\n").append(body.toSource(depth+1));
        }
        return sb.toString();
    }

    /**
     * Visits this node, the initializer expression, the loop condition
     * expression, the increment expression, and then the loop body.
     */
    @Override
    public void visit(NodeVisitor v) {
        if (v.visit(this)) {
            initializer.visit(v);
            condition.visit(v);
            increment.visit(v);
            body.visit(v);
        }
    }
}