/*
    * 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.log4j.chainsaw.layout;
  
  import org.apache.log4j.LogManager;
  import org.apache.log4j.PatternLayout;
  
  import java.io.BufferedReader;
  import java.io.InputStreamReader;
  import java.net.URL;
  
  
  /**
   * Factory class to load and cache Layout information from resources.
   *
   * @author Paul Smith <psmith@apache.org>
   */
  public class DefaultLayoutFactory {
      private volatile static String defaultPatternLayout = null;
  
      private DefaultLayoutFactory() {
      }
  
      public static String getDefaultPatternLayout() {
          return getPatternLayout("org/apache/log4j/chainsaw/layout/DefaultDetailLayout.html");
      }
  
      public static String getFullPatternLayout() {
          return getPatternLayout("org/apache/log4j/chainsaw/layout/FullDetailLayout.html");
      }
  
      private static String getPatternLayout(String fileNamePath) {
          StringBuffer content = new StringBuffer();
          URL defaultLayoutURL =
              DefaultLayoutFactory.class.getClassLoader().getResource(fileNamePath);
  
          if (defaultLayoutURL == null) {
              LogManager.getLogger(DefaultLayoutFactory.class).warn(
                  "Could not locate the default Layout for Event Details and Tooltips");
          } else {
              try {
                  BufferedReader reader = null;
  
                  try {
                      reader =
                          new BufferedReader(
                              new InputStreamReader(defaultLayoutURL.openStream()));
  
                      String line;
  
                      while ((line = reader.readLine()) != null) {
                          content.append(line).append("\n");
                      }
                  } finally {
                      if (reader != null) {
                          reader.close();
                      }
                  }
              } catch (Exception e) {
                  content = new StringBuffer(PatternLayout.TTCC_CONVERSION_PATTERN);
              }
              String trimmedContent = content.toString().trim();
              //the default docs contain the apache license header, strip that out before displaying
              String startComment = "<!--";
              String endComment = "-->";
              if (trimmedContent.startsWith(startComment)) {
                  int endIndex = trimmedContent.indexOf(endComment);
                  if (endIndex > -1) {
                      trimmedContent = trimmedContent.substring(endIndex + endComment.length()).trim();
                  }
              }
              defaultPatternLayout = trimmedContent;
          }
  
          return defaultPatternLayout;
      }
  }