/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.jasper.tagplugins.jstl.core;

import org.apache.jasper.compiler.tagplugin.TagPlugin;
import org.apache.jasper.compiler.tagplugin.TagPluginContext;

/**
 * Tag plugin for the JSTL {@code <c:if>} tag. Generates optimized Java source for conditional execution.
 */
public final class If implements TagPlugin {

    /**
     * Creates a new instance of the If tag plugin.
     */
    public If() {
    }

    @Override
    public void doTag(TagPluginContext ctxt) {
        String condV = ctxt.getTemporaryVariableName();
        ctxt.generateJavaSource("boolean " + condV + "=");
        ctxt.generateAttribute("test");
        ctxt.generateJavaSource(";");
        if (ctxt.isAttributeSpecified("var")) {
            String scope = "PageContext.PAGE_SCOPE";
            if (ctxt.isAttributeSpecified("scope")) {
                String scopeStr = ctxt.getConstantAttribute("scope");
                if ("request".equals(scopeStr)) {
                    scope = "PageContext.REQUEST_SCOPE";
                } else if ("session".equals(scopeStr)) {
                    scope = "PageContext.SESSION_SCOPE";
                } else if ("application".equals(scopeStr)) {
                    scope = "PageContext.APPLICATION_SCOPE";
                }
            }
            ctxt.generateJavaSource("_jspx_page_context.setAttribute(");
            ctxt.generateAttribute("var");
            ctxt.generateJavaSource(", Boolean.valueOf(" + condV + ")," + scope + ");");
        }
        ctxt.generateJavaSource("if (" + condV + "){");
        ctxt.generateBody();
        ctxt.generateJavaSource("}");
    }
}
