text: /*
   * Copyright 2017 Martin Winandy
   *
   * 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 org.tinylog.core;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  import java.util.Map.Entry;
  
  import org.tinylog.Level;
  import org.tinylog.configuration.Configuration;
  import org.tinylog.configuration.ServiceLoader;
  import org.tinylog.provider.InternalLogger;
  import org.tinylog.runtime.RuntimeProvider;
  import org.tinylog.writers.Writer;
  
  /**
   * Parser for properties based configuration.
   *
   * @see Configuration
   */
  public final class ConfigurationParser {
  
  	/** */
  	private ConfigurationParser() {
  	}
  
  	/**
  	 * Loads the global severity level from configuration.
  	 *
  	 * @return Severity level from configuration or {@link Level#TRACE} if no severity level is configured
  	 */
  	public static Level getGlobalLevel() {
  		return parse(Configuration.get("level"), Level.TRACE);
  	}
  
  	/**
  	 * Loads custom severity levels for packages or classes from configuration.
  	 *
  	 * @return All found custom severity levels
  	 */
  	public static Map<String, Level> getCustomLevels() {
  		Map<String, Level> levels = new HashMap<String, Level>();
  		for (Entry<String, String> entry : Configuration.getSiblings("level@").entrySet()) {
  			String packageOrClass = entry.getKey().substring("level@".length());
  			Level level = parse(entry.getValue(), null);
  			if (level != null) {
  				levels.put(packageOrClass, level);
  			}
  		}
  		return levels;
  	}
  
  	/**
  	 * Loads all tags from writers in configuration.
  	 *
  	 * @return Found tags
  	 */
  	public static List<String> getTags() {
  		List<String> tags = new ArrayList<String>();
  		for (String writerProperty : Configuration.getSiblings("writer").keySet()) {
  			String tag = Configuration.get(writerProperty + ".tag");
  			if (tag != null && !tag.isEmpty() && !tag.equals("-")) {
  				String[] tagArray = tag.split(",");
  				for (String tagArrayItem : tagArray) {
  					tagArrayItem = tagArrayItem.trim();
  					if (!tags.contains(tagArrayItem) && !tagArrayItem.isEmpty()) {
  						tags.add(tagArrayItem);
  					}
  				}
  			}
  		}
  		return tags;
  	}
  
  	/**
  	 * Detects whether writing thread is enabled in configuration.
  	 *
  	 * @return {@code true} if writing thread is explicitly enabled, otherwise {@code false}
  	 */
  	public static boolean isWritingThreadEnabled() {
  		return "true".equalsIgnoreCase(Configuration.get("writingthread"));
  	}
  
  	/**
  	 * Detects whether auto shutdown is enabled in configuration.
  	 *
  	 * @return {@code false} if auto shutdown is explicitly disabled, otherwise {@code true}
  	 */
  	public static boolean isAutoShutdownEnabled() {
  		return !"false".equalsIgnoreCase(Configuration.get("autoshutdown"));
  	}
  
  	/**
  	 * Creates a two-dimensional matrix with all configured writers. The first dimension represents the tags. It starts
  	 * with untagged writers, following with all tagged writers and ending with writers that accepts all kind of log
  	 * entries. The total number of entries is the number of defined tags plus two. The second dimension represents the
  	 * severity level. It starts with {@link Level#TRACE} and ends with {@link Level#ERROR}.
  	 *
  	 * @param tags
  	 *            Order of defined tags
  	 * @param minimumLevel
  	 *            Minimum global severity level
  	 * @param writingThread
  	 *            Defines whether {@link WritingThread} is enabled
  	 * @return Matrix with all created writers
  	 */
  	@SuppressWarnings("unchecked")
  	public static Collection<Writer>[][] createWriters(final List<String> tags, final Level minimumLevel, final boolean writingThread) {
  		if (RuntimeProvider.getProcessId() == Long.MIN_VALUE) {
  			java.util.ServiceLoader.load(Writer.class); // Workaround for ProGuard (see issue #126)
  		}
  
  		Collection<Writer>[][] matrix = new Collection[tags.size() + 2][Level.values().length - 1];
  		ServiceLoader<Writer> loader = new ServiceLoader<Writer>(Writer.class, Map.class);
  
  		Map<String, String> writerProperties = Configuration.getSiblings("writer");
  
  		if (writerProperties.isEmpty()) {
  			writerProperties = Collections.singletonMap("writer", RuntimeProvider.getDefaultWriter());
  		}
  
  		for (Entry<String, String> entry : writerProperties.entrySet()) {
  			Map<String, String> configuration = Configuration.getChildren(entry.getKey());
  
  			String tag = configuration.get("tag");
  			Level level = parse(configuration.get("level"), minimumLevel);
  			if (level.ordinal() < minimumLevel.ordinal()) {
  				level = minimumLevel;
  			}
  
  			if (level == Level.OFF) {
  				continue;
  			}
  
  			String exception = Configuration.get("exception");
  			if (exception != null && !configuration.containsKey("exception")) {
  				configuration.put("exception", exception);
  			}
  
  			configuration.remove("tag");
  			configuration.remove("level");
  
  			configuration.put("writingthread", Boolean.toString(writingThread));
  
  			Writer writer = loader.create(entry.getValue(), configuration);
  			if (writer != null) {
  				if (tag == null || tag.isEmpty()) {
  					for (int tagIndex = 0; tagIndex < matrix.length; ++tagIndex) {
  						addWriter(writer, matrix, tagIndex, level);
  					}
  				} else if (tag.equals("-")) {
  					addWriter(writer, matrix, 0, level);
  				} else {
  					String[] tagArray = tag.split(",");
  					for (String tagArrayItem : tagArray) {
  						tagArrayItem = tagArrayItem.trim(); 
  						if (!tagArrayItem.isEmpty()) {
  							addWriter(writer, matrix, tags.indexOf(tagArrayItem) + 1, level);
  						}
  					}
  					
  				}
  			}
  		}
  
  		for (int tagIndex = 0; tagIndex < matrix.length; ++tagIndex) {
  			for (int levelIndex = 0; levelIndex < matrix[tagIndex].length; ++levelIndex) {
  				if (matrix[tagIndex][levelIndex] == null) {
  					matrix[tagIndex][levelIndex] = Collections.emptyList();
  				}
  			}
  		}
  
  		return matrix;
  	}
  
  	/**
  	 * Adds a writer to a well-defined matrix. The given writer will be added only at the given tag index for severity
  	 * levels equal or above the given severity level.
  	 *
  	 * @param writer
  	 *            Writer to add
  	 * @param matrix
  	 *            Well-defined two-dimensional matrix
  	 * @param tagIndex
  	 *            Represents the tag (first dimension of matrix)
  	 * @param level
  	 *            Represents the severity level (second dimension of matrix)
  	 */
  	private static void addWriter(final Writer writer, final Collection<Writer>[][] matrix, final int tagIndex, final Level level) {
  		for (int levelIndex = level.ordinal(); levelIndex < Level.OFF.ordinal(); ++levelIndex) {
  			Collection<Writer> collection = matrix[tagIndex][levelIndex];
  			if (collection == null) {
  				collection = new ArrayList<Writer>();
  				matrix[tagIndex][levelIndex] = collection;
  			}
  			collection.add(writer);
  		}
  	}
  
  	/**
  	 * Reads a severity level from configuration.
  	 *
  	 * @param property
  	 *            Key of property
  	 * @param defaultValue
  	 *            Default value, if property doesn't exist or is invalid
  	 * @return Severity level
  	 */
  	private static Level parse(final String property, final Level defaultValue) {
  		if (property == null) {
  			return defaultValue;
  		} else {
  			try {
  				return Level.valueOf(property.toUpperCase(Locale.ROOT));
  			} catch (IllegalArgumentException ex) {
  				InternalLogger.log(Level.ERROR, "Illegal severity level: " + property);
  				return defaultValue;
  			}
  		}
  	}
  
  }
  