/*
    * 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.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;
  import org.apache.logging.log4j.util.PerformanceSensitive;
  import org.apache.logging.log4j.util.Strings;
  
  /**
   * Highlight pattern converter. Formats the result of a pattern using a color appropriate for the Level in the LogEvent.
   * <p>
   * For example:
   * </p>
   *
   * <pre>
   * %highlight{%d{ ISO8601 } [%t] %-5level: %msg%n%throwable}
   * </pre>
   * <p>
   * You can define custom colors for each Level:
   * </p>
   *
   * <pre>
   * %highlight{%d{ ISO8601 } [%t] %-5level: %msg%n%throwable}{FATAL=red, ERROR=red, WARN=yellow, INFO=green, DEBUG=cyan,
   * TRACE=black}
   * </pre>
   * <p>
   * You can use a predefined style:
   * </p>
   *
   * <pre>
   * %highlight{%d{ ISO8601 } [%t] %-5level: %msg%n%throwable}{STYLE=DEFAULT}
   * </pre>
   * <p>
   * The available predefined styles are:
   * </p>
   * <ul>
   * <li>{@code Default}</li>
   * <li>{@code Log4j} - The same as {@code Default}</li>
   * <li>{@code Logback}</li>
   * </ul>
   * <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>
   *
   * <p>
   * To disable ANSI output unconditionally, specify an additional option <code>disableAnsi=true</code>, or to
   * disable ANSI output if no console is detected, specify option <code>noConsoleNoAnsi=true</code> e.g..
   * </p>
   * <pre>
    * %highlight{%d{ ISO8601 } [%t] %-5level: %msg%n%throwable}{STYLE=DEFAULT, noConsoleNoAnsi=true}
    * </pre>
   */
  @Plugin(name = "highlight", category = PatternConverter.CATEGORY)
  @ConverterKeys({ "highlight" })
  @PerformanceSensitive("allocation")
  public final class HighlightConverter extends LogEventPatternConverter implements AnsiConverter {
  
      private static final Map<Level, String> DEFAULT_STYLES = new HashMap<>();
  
      private static final Map<Level, String> LOGBACK_STYLES = new HashMap<>();
  
      private static final String STYLE_KEY = "STYLE";
  
      private static final String STYLE_KEY_DEFAULT = "DEFAULT";
  
      private static final String STYLE_KEY_LOGBACK = "LOGBACK";
  
      private static final Map<String, Map<Level, String>> STYLES = new HashMap<>();
  
      static {
          // Default styles:
          DEFAULT_STYLES.put(Level.FATAL, AnsiEscape.createSequence("BRIGHT", "RED"));
          DEFAULT_STYLES.put(Level.ERROR, AnsiEscape.createSequence("BRIGHT", "RED"));
          DEFAULT_STYLES.put(Level.WARN, AnsiEscape.createSequence("YELLOW"));
         DEFAULT_STYLES.put(Level.INFO, AnsiEscape.createSequence("GREEN"));
         DEFAULT_STYLES.put(Level.DEBUG, AnsiEscape.createSequence("CYAN"));
         DEFAULT_STYLES.put(Level.TRACE, AnsiEscape.createSequence("BLACK"));
         // Logback styles:
         LOGBACK_STYLES.put(Level.FATAL, AnsiEscape.createSequence("BLINK", "BRIGHT", "RED"));
         LOGBACK_STYLES.put(Level.ERROR, AnsiEscape.createSequence("BRIGHT", "RED"));
         LOGBACK_STYLES.put(Level.WARN, AnsiEscape.createSequence("RED"));
         LOGBACK_STYLES.put(Level.INFO, AnsiEscape.createSequence("BLUE"));
         LOGBACK_STYLES.put(Level.DEBUG, AnsiEscape.createSequence((String[]) null));
         LOGBACK_STYLES.put(Level.TRACE, AnsiEscape.createSequence((String[]) 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:
      * </p>
      *
      * <pre>
      * Level1=Value, Level2=Value, ...
      * </pre>
      *
      * <p>
      * For example:
      * </p>
      *
      * <pre>
      * ERROR=red bold, WARN=yellow bold, INFO=green, ...
      * </pre>
      *
      * <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>
      *
      * @param options
      *        The second slot can optionally contain the style map.
      * @return a new map
      */
     private static Map<Level, String> createLevelStyleMap(final String[] options) {
         if (options.length < 2) {
             return DEFAULT_STYLES;
         }
         // Feels like a hack. Should String[] options change to a Map<String,String>?
         final String string = options[1]
                 .replaceAll(PatternParser.DISABLE_ANSI + "=(true|false)", Strings.EMPTY)
                 .replaceAll(PatternParser.NO_CONSOLE_NO_ANSI + "=(true|false)", Strings.EMPTY);
         //
         final Map<String, String> styles = AnsiEscape.createMap(string, new String[] {STYLE_KEY});
         final Map<Level, String> levelStyles = new HashMap<>(DEFAULT_STYLES);
         for (final 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 Map<Level, String> enumMap = STYLES.get(value.toUpperCase(Locale.ENGLISH));
                 if (enumMap == null) {
                     LOGGER.error("Unknown level style: " + value + ". Use one of " +
                         Arrays.toString(STYLES.keySet().toArray()));
                 } else {
                     levelStyles.putAll(enumMap);
                 }
             } else {
                 final Level level = Level.toLevel(key, null);
                 if (level == null) {
                     LOGGER.error("Unknown level name: {}; use one of {}", key, Arrays.toString(Level.values()));
                 } 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(final 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;
         }
         final PatternParser parser = PatternLayout.createPatternParser(config);
         final List<PatternFormatter> formatters = parser.parse(options[0]);
         final boolean disableAnsi = Arrays.toString(options).contains(PatternParser.DISABLE_ANSI + "=true");
         final boolean noConsoleNoAnsi = Arrays.toString(options).contains(PatternParser.NO_CONSOLE_NO_ANSI + "=true");
         final boolean hideAnsi = disableAnsi || (noConsoleNoAnsi && System.console() == null);
         return new HighlightConverter(formatters, createLevelStyleMap(options), hideAnsi);
     }
 
     private final Map<Level, String> levelStyles;
 
     private final List<PatternFormatter> patternFormatters;
 
     private final boolean noAnsi;
 
     private final String defaultStyle;
 
     /**
      * Construct the converter.
      *
      * @param patternFormatters
      *            The PatternFormatters to generate the text to manipulate.
      * @param noAnsi
      *            If true, do not output ANSI escape codes.
      */
     private HighlightConverter(final List<PatternFormatter> patternFormatters, final Map<Level, String> levelStyles, final boolean noAnsi) {
         super("style", "style");
         this.patternFormatters = patternFormatters;
         this.levelStyles = levelStyles;
         this.defaultStyle = AnsiEscape.getDefaultStyle();
         this.noAnsi = noAnsi;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void format(final LogEvent event, final StringBuilder toAppendTo) {
         int start = 0;
         int end = 0;
         if (!noAnsi) { // use ANSI: set prefix
             start = toAppendTo.length();
             toAppendTo.append(levelStyles.get(event.getLevel()));
             end = toAppendTo.length();
         }
 
         //noinspection ForLoopReplaceableByForEach
         for (int i = 0, size = patternFormatters.size(); i <  size; i++) {
             patternFormatters.get(i).format(event, toAppendTo);
         }
 
         // if we use ANSI we need to add the postfix or erase the unnecessary prefix
         final boolean empty = toAppendTo.length() == end;
         if (!noAnsi) {
             if (empty) {
                 toAppendTo.setLength(start); // erase prefix
             } else {
                 toAppendTo.append(defaultStyle); // add postfix
             }
         }
     }
 
     String getLevelStyle(Level level) {
         return levelStyles.get(level);
     }
 
     @Override
     public boolean handlesThrowable() {
         for (final PatternFormatter formatter : patternFormatters) {
             if (formatter .handlesThrowable()) {
                 return true;
             }
         }
         return false;
     }
 
 }