/*
 * 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 com.opensymphony.xwork2.config;

import com.opensymphony.xwork2.config.entities.PackageConfig;
import org.apache.commons.lang3.StringUtils;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.StringTokenizer;

/**
 * ConfigurationUtil
 * 
 * @author Jason Carreira Created May 23, 2003 11:22:49 PM
 */
public class ConfigurationUtil {

    private static final Logger LOG = LogManager.getLogger(ConfigurationUtil.class);

    private ConfigurationUtil() {
    }

    /**
     * Get the {@link PackageConfig} elements with the specified names.
     * @param configuration Configuration from which to find the package elements
     * @param parent Comma separated list of parent package names
     * @return The package elements that correspond to the names in the {@code parent} parameter.
     */
    public static List<PackageConfig> buildParentsFromString(Configuration configuration, String parent) {
        List<String> parentPackageNames = buildParentListFromString(parent);
        List<PackageConfig> parentPackageConfigs = new ArrayList<>();
        for (String parentPackageName : parentPackageNames) {
            PackageConfig parentPackageContext = configuration.getPackageConfig(parentPackageName);

            if (parentPackageContext != null) {
                parentPackageConfigs.add(parentPackageContext);
            }
        }

        return parentPackageConfigs;
    }

    /**
     * Splits the string into a list using a comma as the token separator.
     * @param parent The comma separated string.
     * @return A list of tokens from the specified string.
     */
    public static List<String> buildParentListFromString(String parent) {
        if (StringUtils.isEmpty(parent)) {
            return Collections.emptyList();
        }

        StringTokenizer tokenizer = new StringTokenizer(parent, ",");
        List<String> parents = new ArrayList<>();

        while (tokenizer.hasMoreTokens()) {
            String parentName = tokenizer.nextToken().trim();

            if (StringUtils.isNotEmpty(parentName)) {
                parents.add(parentName);
            }
        }

        return parents;
    }
}