/*
 * Copyright 2014 Attila Szegedi, Daniel Dekany, Jonathan Revusky
 * 
 * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package freemarker.core;

import freemarker.template.TemplateException;

final class NotExpression extends BooleanExpression {

    private final Expression target;

    NotExpression(Expression target) {
        this.target = target;
    }

    @Override
    boolean evalToBoolean(Environment env) throws TemplateException {
        return (!target.evalToBoolean(env));
    }

    @Override
    public String getCanonicalForm() {
        return "!" + target.getCanonicalForm();
    }
 
    @Override
    String getNodeTypeSymbol() {
        return "!";
    }
    
    @Override
    boolean isLiteral() {
        return target.isLiteral();
    }

    @Override
    protected Expression deepCloneWithIdentifierReplaced_inner(
            String replacedIdentifier, Expression replacement, ReplacemenetState replacementState) {
    	return new NotExpression(
    	        target.deepCloneWithIdentifierReplaced(replacedIdentifier, replacement, replacementState));
    }

    @Override
    int getParameterCount() {
        return 1;
    }

    @Override
    Object getParameterValue(int idx) {
        if (idx != 0) throw new IndexOutOfBoundsException();
        return target;
    }

    @Override
    ParameterRole getParameterRole(int idx) {
        if (idx != 0) throw new IndexOutOfBoundsException();
        return ParameterRole.RIGHT_HAND_OPERAND;
    }
}