/*
    * 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.layout;
  
  import java.nio.charset.Charset;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.logging.log4j.core.Layout;
  import org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.core.config.Configuration;
  import org.apache.logging.log4j.core.config.DefaultConfiguration;
  import org.apache.logging.log4j.core.config.Node;
  import org.apache.logging.log4j.core.config.plugins.Plugin;
  import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
  import org.apache.logging.log4j.core.config.plugins.PluginBuilderAttribute;
  import org.apache.logging.log4j.core.config.plugins.PluginBuilderFactory;
  import org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
  import org.apache.logging.log4j.core.config.plugins.PluginElement;
  import org.apache.logging.log4j.core.config.plugins.PluginFactory;
  import org.apache.logging.log4j.core.pattern.LogEventPatternConverter;
  import org.apache.logging.log4j.core.pattern.PatternFormatter;
  import org.apache.logging.log4j.core.pattern.PatternParser;
  import org.apache.logging.log4j.core.pattern.RegexReplacement;
  
  /**
   * A flexible layout configurable with pattern string.
   * <p>
   * The goal of this class is to {@link org.apache.logging.log4j.core.Layout#toByteArray format} a {@link LogEvent} and
   * return the results. The format of the result depends on the <em>conversion pattern</em>.
   * </p>
   * <p>
   * The conversion pattern is closely related to the conversion pattern of the printf function in C. A conversion pattern
   * is composed of literal text and format control expressions called <em>conversion specifiers</em>.
   * </p>
   * <p>
   * See the Log4j Manual for details on the supported pattern converters.
   * </p>
   */
  @Plugin(name = "PatternLayout", category = Node.CATEGORY, elementType = Layout.ELEMENT_TYPE, printObject = true)
  public final class PatternLayout extends AbstractStringLayout {
  
      private static final long serialVersionUID = 1L;
  
      /**
       * Default pattern string for log output. Currently set to the
       * string <b>"%m%n"</b> which just prints the application supplied
       * message.
       */
      public static final String DEFAULT_CONVERSION_PATTERN = "%m%n";
  
      /**
       * A conversion pattern equivalent to the TTCCCLayout.
       * Current value is <b>%r [%t] %p %c %x - %m%n</b>.
       */
      public static final String TTCC_CONVERSION_PATTERN =
          "%r [%t] %p %c %x - %m%n";
  
      /**
       * A simple pattern.
       * Current value is <b>%d [%t] %p %c - %m%n</b>.
       */
      public static final String SIMPLE_CONVERSION_PATTERN =
          "%d [%t] %p %c - %m%n";
  
      /** Key to identify pattern converters. */
      public static final String KEY = "Converter";
  
      /**
       * Initial converter for pattern.
       */
      private final PatternFormatter[] formatters;
  
      private static ThreadLocal<StringBuilder> strBuilder = new ThreadLocal<StringBuilder>() {
          @Override
          protected StringBuilder initialValue() {
              return new StringBuilder(1024);
          }        
      };
  
      /**
       * Conversion pattern.
       */
      private final String conversionPattern;
 
 
     /**
      * The current Configuration.
      */
     private final Configuration config;
 
     private final RegexReplacement replace;
 
     private final boolean alwaysWriteExceptions;
 
     private final boolean noConsoleNoAnsi;
 
     /**
      * Constructs a EnhancedPatternLayout using the supplied conversion pattern.
      *
      * @param config The Configuration.
      * @param replace The regular expression to match.
      * @param pattern conversion pattern.
      * @param charset The character set.
      * @param alwaysWriteExceptions Whether or not exceptions should always be handled in this pattern (if {@code true},
      *                         exceptions will be written even if the pattern does not specify so).
      * @param noConsoleNoAnsi
      *            If {@code "true"} (default) and {@link System#console()} is null, do not output ANSI escape codes
      * @param header
      */
     private PatternLayout(final Configuration config, final RegexReplacement replace, final String pattern,
                           final Charset charset, final boolean alwaysWriteExceptions, final boolean noConsoleNoAnsi,
                           final String header, final String footer) {
         super(charset, toBytes(header, charset), toBytes(footer, charset));
         this.replace = replace;
         this.conversionPattern = pattern;
         this.config = config;
         this.alwaysWriteExceptions = alwaysWriteExceptions;
         this.noConsoleNoAnsi = noConsoleNoAnsi;
         final PatternParser parser = createPatternParser(config);
         try {
             List<PatternFormatter> list = parser.parse(pattern == null ? DEFAULT_CONVERSION_PATTERN : pattern, 
                     this.alwaysWriteExceptions, this.noConsoleNoAnsi);
             this.formatters = list.toArray(new PatternFormatter[0]);
         } catch (RuntimeException ex) {
             throw new IllegalArgumentException("Cannot parse pattern '" + pattern + "'", ex);
         }
     }
 
     private byte[] strSubstitutorReplace(final byte... b) {
         if (b != null && config != null) {
             return getBytes(config.getStrSubstitutor().replace(new String(b, getCharset())));
         }
         return b;
     }
 
     @Override
     public byte[] getHeader() {
         return strSubstitutorReplace(super.getHeader());
     }
 
     @Override
     public byte[] getFooter() {
         return strSubstitutorReplace(super.getFooter());
     }
 
     /**
      * Gets the conversion pattern.
      *
      * @return the conversion pattern.
      */
     public String getConversionPattern() {
         return conversionPattern;
     }
 
     /**
      * Gets this PatternLayout's content format. Specified by:
      * <ul>
      * <li>Key: "structured" Value: "false"</li>
      * <li>Key: "formatType" Value: "conversion" (format uses the keywords supported by OptionConverter)</li>
      * <li>Key: "format" Value: provided "conversionPattern" param</li>
      * </ul>
      * 
      * @return Map of content format keys supporting PatternLayout
      */
     @Override
     public Map<String, String> getContentFormat()
     {
         final Map<String, String> result = new HashMap<>();
         result.put("structured", "false");
         result.put("formatType", "conversion");
         result.put("format", conversionPattern);
         return result;
     }
 
     /**
      * Formats a logging event to a writer.
      *
      *
      * @param event logging event to be formatted.
      * @return The event formatted as a String.
      */
     @Override
     public String toSerializable(final LogEvent event) {
         final StringBuilder buf = strBuilder.get();
         buf.setLength(0);
         final int len = formatters.length;
         for (int i = 0; i < len; i++) {
             formatters[i].format(event, buf);
         }
         String str = buf.toString();
         if (replace != null) {
             str = replace.format(str);
         }
         return str;
     }
 
     /**
      * Create a PatternParser.
      * @param config The Configuration.
      * @return The PatternParser.
      */
     public static PatternParser createPatternParser(final Configuration config) {
         if (config == null) {
             return new PatternParser(config, KEY, LogEventPatternConverter.class);
         }
         PatternParser parser = config.getComponent(KEY);
         if (parser == null) {
             parser = new PatternParser(config, KEY, LogEventPatternConverter.class);
             config.addComponent(KEY, parser);
             parser = (PatternParser) config.getComponent(KEY);
         }
         return parser;
     }
 
     @Override
     public String toString() {
         return conversionPattern;
     }
 
     /**
      * Create a pattern layout.
      *
      * @param pattern
      *        The pattern. If not specified, defaults to DEFAULT_CONVERSION_PATTERN.
      * @param config
      *        The Configuration. Some Converters require access to the Interpolator.
      * @param replace
      *        A Regex replacement String.
      * @param charset
      *        The character set.
      * @param alwaysWriteExceptions
      *        If {@code "true"} (default) exceptions are always written even if the pattern contains no exception tokens.
      * @param noConsoleNoAnsi
      *        If {@code "true"} (default is false) and {@link System#console()} is null, do not output ANSI escape codes
      * @param header
      *        The footer to place at the top of the document, once.
      * @param footer
      *        The footer to place at the bottom of the document, once.
      * @return The PatternLayout.
      */
     @PluginFactory
     public static PatternLayout createLayout(
             @PluginAttribute(value = "pattern", defaultString = DEFAULT_CONVERSION_PATTERN) final String pattern,
             @PluginConfiguration final Configuration config,
             @PluginElement("Replace") final RegexReplacement replace,
             @PluginAttribute(value = "charset", defaultString = "UTF-8") final Charset charset,
             @PluginAttribute(value = "alwaysWriteExceptions", defaultBoolean = true) final boolean alwaysWriteExceptions,
             @PluginAttribute(value = "noConsoleNoAnsi", defaultBoolean = false) final boolean noConsoleNoAnsi,
             @PluginAttribute("header") final String header,
             @PluginAttribute("footer") final String footer) {
         return newBuilder()
             .withPattern(pattern)
             .withConfiguration(config)
             .withRegexReplacement(replace)
             .withCharset(charset)
             .withAlwaysWriteExceptions(alwaysWriteExceptions)
             .withNoConsoleNoAnsi(noConsoleNoAnsi)
             .withHeader(header)
             .withFooter(footer)
             .build();
     }
 
     /**
      * Creates a PatternLayout using the default options. These options include using UTF-8, the default conversion
      * pattern, exceptions being written, and with ANSI escape codes.
      *
      * @return the PatternLayout.
      * @see #DEFAULT_CONVERSION_PATTERN Default conversion pattern
      */
     public static PatternLayout createDefaultLayout() {
         return newBuilder().build();
     }
 
     /**
      * Creates a builder for a custom PatternLayout.
      * @return a PatternLayout builder.
      */
     @PluginBuilderFactory
     public static Builder newBuilder() {
         return new Builder();
     }
 
     /**
      * Custom PatternLayout builder. Use the {@link PatternLayout#newBuilder() builder factory method} to create this.
      */
     public static class Builder implements org.apache.logging.log4j.core.util.Builder<PatternLayout> {
 
         // FIXME: it seems rather redundant to repeat default values (same goes for field names)
         // perhaps introduce a @PluginBuilderAttribute that has no values of its own and uses reflection?
 
         @PluginBuilderAttribute
         private String pattern = PatternLayout.DEFAULT_CONVERSION_PATTERN;
 
         @PluginConfiguration
         private Configuration configuration = null;
 
         @PluginElement("Replace")
         private RegexReplacement regexReplacement = null;
 
         // LOG4J2-783 use platform default by default
         @PluginBuilderAttribute
         private Charset charset = Charset.defaultCharset();
 
         @PluginBuilderAttribute
         private boolean alwaysWriteExceptions = true;
 
         @PluginBuilderAttribute
         private boolean noConsoleNoAnsi = false;
 
         @PluginBuilderAttribute
         private String header = null;
 
         @PluginBuilderAttribute
         private String footer = null;
 
         private Builder() {
         }
 
         // TODO: move javadocs from PluginFactory to here
 
         public Builder withPattern(final String pattern) {
             this.pattern = pattern;
             return this;
         }
 
 
         public Builder withConfiguration(final Configuration configuration) {
             this.configuration = configuration;
             return this;
         }
 
         public Builder withRegexReplacement(final RegexReplacement regexReplacement) {
             this.regexReplacement = regexReplacement;
             return this;
         }
 
         public Builder withCharset(final Charset charset) {
             this.charset = charset;
             return this;
         }
 
         public Builder withAlwaysWriteExceptions(final boolean alwaysWriteExceptions) {
             this.alwaysWriteExceptions = alwaysWriteExceptions;
             return this;
         }
 
         public Builder withNoConsoleNoAnsi(final boolean noConsoleNoAnsi) {
             this.noConsoleNoAnsi = noConsoleNoAnsi;
             return this;
         }
 
         public Builder withHeader(final String header) {
             this.header = header;
             return this;
         }
 
         public Builder withFooter(final String footer) {
             this.footer = footer;
             return this;
         }
 
         @Override
         public PatternLayout build() {
             // fall back to DefaultConfiguration
             if (configuration == null) {
                 configuration = new DefaultConfiguration();
             }
             return new PatternLayout(configuration, regexReplacement, pattern, charset, alwaysWriteExceptions,
                 noConsoleNoAnsi, header, footer);
         }
     }
 }