/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
    *
    * This program and the accompanying materials are dual-licensed under
    * either the terms of the Eclipse Public License v1.0 as published by
    * the Eclipse Foundation
    *
    *   or (per the licensee's choosing)
   *
   * under the terms of the GNU Lesser General Public License version 2.1
   * as published by the Free Software Foundation.
   */
  package ch.qos.logback.core.pattern;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import ch.qos.logback.core.Context;
  import ch.qos.logback.core.CoreConstants;
  import ch.qos.logback.core.LayoutBase;
  import ch.qos.logback.core.pattern.parser.Node;
  import ch.qos.logback.core.pattern.parser.Parser;
  import ch.qos.logback.core.spi.ScanException;
  import ch.qos.logback.core.status.ErrorStatus;
  import ch.qos.logback.core.status.StatusManager;
  
  abstract public class PatternLayoutBase<E> extends LayoutBase<E> {
  
      static final int INTIAL_STRING_BUILDER_SIZE = 256;
      Converter<E> head;
      String pattern;
      protected PostCompileProcessor<E> postCompileProcessor;
  
      Map<String, String> instanceConverterMap = new HashMap<String, String>();
      protected boolean outputPatternAsHeader = false;
  
      /**
       * Concrete implementations of this class are responsible for elaborating the
       * mapping between pattern words and converters.
       * 
       * @return A map associating pattern words to the names of converter classes
       */
      abstract public Map<String, String> getDefaultConverterMap();
  
      /**
       * Returns a map where the default converter map is merged with the map
       * contained in the context.
       */
      public Map<String, String> getEffectiveConverterMap() {
          Map<String, String> effectiveMap = new HashMap<String, String>();
  
          // add the least specific map fist
          Map<String, String> defaultMap = getDefaultConverterMap();
          if (defaultMap != null) {
              effectiveMap.putAll(defaultMap);
          }
  
          // contextMap is more specific than the default map
          Context context = getContext();
          if (context != null) {
              @SuppressWarnings("unchecked")
              Map<String, String> contextMap = (Map<String, String>) context
                      .getObject(CoreConstants.PATTERN_RULE_REGISTRY);
              if (contextMap != null) {
                  effectiveMap.putAll(contextMap);
              }
          }
          // set the most specific map last
          effectiveMap.putAll(instanceConverterMap);
          return effectiveMap;
      }
  
      public void start() {
          if (pattern == null || pattern.length() == 0) {
              addError("Empty or null pattern.");
              return;
          }
          try {
              Parser<E> p = new Parser<E>(pattern);
              if (getContext() != null) {
                  p.setContext(getContext());
              }
              Node t = p.parse();
              this.head = p.compile(t, getEffectiveConverterMap());
              if (postCompileProcessor != null) {
                  postCompileProcessor.process(context, head);
              }
              ConverterUtil.setContextForConverters(getContext(), head);
              ConverterUtil.startConverters(this.head);
              super.start();
          } catch (ScanException sce) {
              StatusManager sm = getContext().getStatusManager();
              sm.add(new ErrorStatus("Failed to parse pattern \"" + getPattern() + "\".", this, sce));
          }
      }
  
      public void setPostCompileProcessor(PostCompileProcessor<E> postCompileProcessor) {
          this.postCompileProcessor = postCompileProcessor;
     }
 
     /**
      *
      * @param head
      * @deprecated Use {@link ConverterUtil#setContextForConverters} instead. This
      *             method will be removed in future releases.
      */
     protected void setContextForConverters(Converter<E> head) {
         ConverterUtil.setContextForConverters(getContext(), head);
     }
 
     protected String writeLoopOnConverters(E event) {
         StringBuilder strBuilder = new StringBuilder(INTIAL_STRING_BUILDER_SIZE);
         Converter<E> c = head;
         while (c != null) {
             c.write(strBuilder, event);
             c = c.getNext();
         }
         return strBuilder.toString();
     }
 
     public String getPattern() {
         return pattern;
     }
 
     public void setPattern(String pattern) {
         this.pattern = pattern;
     }
 
     public String toString() {
         return this.getClass().getName() + "(\"" + getPattern() + "\")";
     }
 
     public Map<String, String> getInstanceConverterMap() {
         return instanceConverterMap;
     }
 
     protected String getPresentationHeaderPrefix() {
         return CoreConstants.EMPTY_STRING;
     }
 
     public boolean isOutputPatternAsHeader() {
         return outputPatternAsHeader;
     }
 
     public void setOutputPatternAsHeader(boolean outputPatternAsHeader) {
         this.outputPatternAsHeader = outputPatternAsHeader;
     }
 
     @Override
     public String getPresentationHeader() {
         if (outputPatternAsHeader)
             return getPresentationHeaderPrefix() + pattern;
         else
             return super.getPresentationHeader();
     }
 }