/*
    * 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.logging.log4j.core.pattern;
  
  import java.util.Arrays;
  import java.util.EnumMap;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  
  import org.apache.logging.log4j.Level;
  import org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.core.config.Configuration;
  import org.apache.logging.log4j.core.config.plugins.Plugin;
  import org.apache.logging.log4j.core.layout.PatternLayout;
  
  /**
   * Highlight pattern converter. Formats the result of a pattern using a color appropriate for the Level in the LogEvent.
   * <p>
   * For example:
   * 
   * <pre>
   * %highlight{%d{ ISO8601 } [%t] %-5level: %msg%n%throwable}
   * </pre>
   * </p>
   * 
   * <p>
   * You can define custom colors for each Level:
   * 
   * <pre>
   * %highlight{%d{ ISO8601 } [%t] %-5level: %msg%n%throwable}{FATAL=red, ERROR=red, WARN=yellow, INFO=green, DEBUG=cyan, TRACE=black}
   * </pre>
   * </p>
   * 
   * <p>
   * You can use a predefined style:
   * 
   * <pre>
   * %highlight{%d{ ISO8601 } [%t] %-5level: %msg%n%throwable}{STYLE=Log4J}
   * </pre>
   * The available predefined styles are:
   * <ul>
   * <li>{@code Default}</li>
   * <li>{@code Log4J} - The same as {@code Default}</li>
   * <li>{@code Logback}</li>
   * </ul>
   * </p>
   * 
   * <p>
   * You can use whitespace around the comma and equal sign. The names in values MUST come from the {@linkplain AnsiEscape} enum, case is
   * normalized to upper-case internally.
   * </p>
   */
  @Plugin(name = "highlight", type = "Converter")
  @ConverterKeys({ "highlight" })
  public final class HighlightConverter extends LogEventPatternConverter {
  
      private static final String STYLE_KEY_DEFAULT = "DEFAULT";
  
      private static final String STYLE_KEY_LOGBACK = "LOGBACK";
  
      private static final String STYLE_KEY = "STYLE";
  
      private static final EnumMap<Level, String> DEFAULT_STYLES = new EnumMap<Level, String>(Level.class);
  
      private static final EnumMap<Level, String> LOGBACK_STYLES = new EnumMap<Level, String>(Level.class);
  
      private static final Map<String, EnumMap<Level, String>> STYLES = new HashMap<String, EnumMap<Level, String>>();
  
      static {
          // Default styles:
          DEFAULT_STYLES.put(Level.FATAL, AnsiEscape.createSequence(new String[] { "BRIGHT", "RED" }));
          DEFAULT_STYLES.put(Level.ERROR, AnsiEscape.createSequence(new String[] { "BRIGHT", "RED" }));
          DEFAULT_STYLES.put(Level.WARN, AnsiEscape.createSequence(new String[] { "YELLOW" }));
          DEFAULT_STYLES.put(Level.INFO, AnsiEscape.createSequence(new String[] { "GREEN" }));
          DEFAULT_STYLES.put(Level.DEBUG, AnsiEscape.createSequence(new String[] { "CYAN" }));
          DEFAULT_STYLES.put(Level.TRACE, AnsiEscape.createSequence(new String[] { "BLACK" }));
          // Logback styles:
          LOGBACK_STYLES.put(Level.FATAL, AnsiEscape.createSequence(new String[] { "BLINK", "BRIGHT", "RED" }));
          LOGBACK_STYLES.put(Level.ERROR, AnsiEscape.createSequence(new String[] { "BRIGHT", "RED" }));
          LOGBACK_STYLES.put(Level.WARN, AnsiEscape.createSequence(new String[] { "RED" }));
          LOGBACK_STYLES.put(Level.INFO, AnsiEscape.createSequence(new String[] { "BLUE" }));
          LOGBACK_STYLES.put(Level.DEBUG, AnsiEscape.createSequence(null));
          LOGBACK_STYLES.put(Level.TRACE, AnsiEscape.createSequence(null));
         // Style map:
         STYLES.put(STYLE_KEY_DEFAULT, DEFAULT_STYLES);
         STYLES.put(STYLE_KEY_LOGBACK, LOGBACK_STYLES);
     }
 
     /**
      * Creates a level style map where values are ANSI escape sequences given configuration options in {@code option[1]}.
      * <p/>
      * The format of the option string in {@code option[1]} is:
      * 
      * <pre>
      * Level1=Value, Level2=Value, ...
      * </pre>
      * 
      * For example:
      * 
      * <pre>
      * ERROR=red bold, WARN=yellow bold, INFO=green, ...
      * </pre>
      * 
      * You can use whitespace around the comma and equal sign. The names in values MUST come from the {@linkplain AnsiEscape} enum, case is
      * normalized to upper-case internally.
      * 
      * @param options
      *            The second slot can optionally contain the style map.
      * @return a new map
      */
     private static EnumMap<Level, String> createLevelStyleMap(final String[] options) {
         if (options.length < 2) {
             return DEFAULT_STYLES;
         }
         Map<String, String> styles = AnsiEscape.createMap(options[1], new String[] { STYLE_KEY });
         EnumMap<Level, String> levelStyles = new EnumMap<Level, String>(DEFAULT_STYLES);
         for (Map.Entry<String, String> entry : styles.entrySet()) {
             final String key = entry.getKey().toUpperCase(Locale.ENGLISH);
             final String value = entry.getValue();
             if (STYLE_KEY.equalsIgnoreCase(key)) {
                 final EnumMap<Level, String> enumMap = STYLES.get(value.toUpperCase(Locale.ENGLISH));
                 if (enumMap == null) {
                     LOGGER.error("Unkown level style: " + value + ". Use one of " + Arrays.toString(STYLES.keySet().toArray()));
                 } else {
                     levelStyles.putAll(enumMap);
                 }
             } else {
                 final Level level = Level.valueOf(key);
                 if (level == null) {
                     LOGGER.error("Unkown level name: " + key + ". Use one of " + Arrays.toString(DEFAULT_STYLES.keySet().toArray()));
                 } else {
                     levelStyles.put(level, value);
                 }
             }
         }
         return levelStyles;
     }
 
     /**
      * Gets an instance of the class.
      * 
      * @param config
      *            The current Configuration.
      * @param options
      *            pattern options, may be null. If first element is "short", only the first line of the throwable will be formatted.
      * @return instance of class.
      */
     public static HighlightConverter newInstance(Configuration config, final String[] options) {
         if (options.length < 1) {
             LOGGER.error("Incorrect number of options on style. Expected at least 1, received " + options.length);
             return null;
         }
         if (options[0] == null) {
             LOGGER.error("No pattern supplied on style");
             return null;
         }
         PatternParser parser = PatternLayout.createPatternParser(config);
         List<PatternFormatter> formatters = parser.parse(options[0]);
         return new HighlightConverter(formatters, createLevelStyleMap(options));
     }
 
     private final List<PatternFormatter> formatters;
 
     private final EnumMap<Level, String> levelStyles;
 
     /**
      * Construct the converter.
      * 
      * @param formatters
      *            The PatternFormatters to generate the text to manipulate.
      */
     private HighlightConverter(List<PatternFormatter> formatters, EnumMap<Level, String> levelStyles) {
         super("style", "style");
         this.formatters = formatters;
         this.levelStyles = levelStyles;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void format(final LogEvent event, final StringBuilder toAppendTo) {
         StringBuilder buf = new StringBuilder();
         for (PatternFormatter formatter : formatters) {
             formatter.format(event, buf);
         }
 
         if (buf.length() > 0) {
             toAppendTo.append(levelStyles.get(event.getLevel())).append(buf.toString()).append(AnsiEscape.getDefaultStyle());
         }
     }
 }