Copyright 2014 Netflix, Inc.
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.
/**
 * Copyright 2014 Netflix, Inc.
 *
 * 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 com.netflix.config;

import org.apache.commons.configuration.AbstractConfiguration;

public class ConfigurationBackedDynamicPropertySupportImpl implements DynamicPropertySupport {

    private final AbstractConfiguration config;
        
    public ConfigurationBackedDynamicPropertySupportImpl(AbstractConfiguration config) {
        if (config == null) {
            throw new NullPointerException("config is null");
        }
        this.config = config;
    }
    
    @Override
    public String getString(String key) {
        try {
            String values[] = config.getStringArray(key);
            if (values == null) {
                return null;
            }
            if (values.length == 0) {
                return config.getString(key);
            } else if (values.length == 1) {
                return values[0];
            }

            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < values.length; i++) {
                sb.append(values[i]);
                if (i != values.length - 1) {
                    sb.append(",");
                }
            }
            return sb.toString();
        } catch (Exception e) {
            Object v = config.getProperty(key);
            if (v != null) {
                return String.valueOf(v);
            } else {
                return null;
            }
        }
    }

    @Override
    public void addConfigurationListener(PropertyListener expandedConfigListener) {
        ExpandedConfigurationListenerAdapter nl = new ExpandedConfigurationListenerAdapter(expandedConfigListener);
        config.addConfigurationListener(nl);    
    }
    
    public final AbstractConfiguration getConfiguration() {
        return config;
    }
}