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/*
 * Copyright 2008-2009 the original author or authors.
 *
 * 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 javarequirementstracer;

import java.io.Closeable;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Map;
import java.util.Properties;
import java.util.SortedMap;
import java.util.TreeMap;

/**
 * Like {@link Properties} but enforces the properties loaded from a file must be unique,
 * though enforcing a property must not be set twice.
 * 
 * @author Ronald Koster
 */
final class UniqueProperties extends Properties {
	private static final long serialVersionUID = 1L;
	private static final Logger LOGGER = Logger.getInstance(UniqueProperties.class);
	
	/**
	 * @throws IllegalArgumentException in case a property is set twice.
	 */
	@Override
	public Object put(Object key, Object value) {
		if (containsKey(key)) {
			throw new IllegalArgumentException("Unique violation: " + key);
		}
		return super.put(key, value);
	}
	
	void load(final File propertiesFile) {
		LOGGER.info("$user.dir = " + System.getProperty("user.dir"));
		LOGGER.info("propertiesFilename = " + propertiesFile.getAbsolutePath());
		FileInputStream input = null;
		try {
			input = new FileInputStream(propertiesFile);
			load(input);
		} catch (FileNotFoundException fnfex) {
			LOGGER.error(fnfex);
			throw new UncheckedException(fnfex);
		} catch (IOException ioex) {
			LOGGER.error(ioex);
			throw new UncheckedException(ioex);
		} finally {
			if (input != null) {
				close(input);
			}
		}
	}
	
	private void close(Closeable stream) {
		try {
			stream.close();
		} catch (IOException ioex) {
			LOGGER.error(ioex);
			throw new UncheckedException(ioex);
		}
	}
	
	SortedMap getAsSortedMap() {
		final SortedMap map = new TreeMap();
		for (Map.Entry entry : entrySet()) {
			String key = (String) entry.getKey();
			String value = (String) entry.getValue();
			map.put(key, value);
		}
		return map;
	}
}