/*
    * 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.maven.plugins.shade.resource;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.OutputStreamWriter;
  import java.io.Writer;
  import java.text.SimpleDateFormat;
  import java.util.Date;
  import java.util.LinkedHashMap;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  import java.util.TreeSet;
  import java.util.jar.JarEntry;
  import java.util.jar.JarOutputStream;
  
  import org.apache.maven.plugins.shade.relocation.Relocator;
  
  /**
   * Merges <code>META-INF/NOTICE.TXT</code> files.
   */
  public class ApacheNoticeResourceTransformer extends AbstractCompatibilityTransformer {
      Set<String> entries = new LinkedHashSet<>();
  
      Map<String, Set<String>> organizationEntries = new LinkedHashMap<>();
  
      String projectName = ""; // MSHADE-101 :: NullPointerException when projectName is missing
  
      boolean addHeader = true;
  
      String preamble1 = "// ------------------------------------------------------------------\n"
              + "// NOTICE file corresponding to the section 4d of The Apache License,\n"
              + "// Version 2.0, in this case for ";
  
      String preamble2 = "\n// ------------------------------------------------------------------\n";
  
      String preamble3 = "This product includes software developed at\n";
  
      // defaults overridable via config in pom
      String organizationName = "The Apache Software Foundation";
  
      String organizationURL = "http://www.apache.org/";
  
      String inceptionYear = "2006";
  
      String copyright;
  
      /**
       * The file encoding of the <code>NOTICE</code> file.
       */
      String encoding;
  
      private long time = Long.MIN_VALUE;
  
      private static final String NOTICE_PATH = "META-INF/NOTICE";
  
      private static final String NOTICE_TXT_PATH = "META-INF/NOTICE.txt";
  
      private static final String NOTICE_MD_PATH = "META-INF/NOTICE.md";
  
      @Override
      public boolean canTransformResource(String resource) {
          return NOTICE_PATH.equalsIgnoreCase(resource)
                  || NOTICE_TXT_PATH.equalsIgnoreCase(resource)
                  || NOTICE_MD_PATH.equalsIgnoreCase(resource);
      }
  
      @Override
      public void processResource(String resource, InputStream is, List<Relocator> relocators, long time)
              throws IOException {
          if (entries.isEmpty()) {
              String year = new SimpleDateFormat("yyyy").format(new Date());
              if (!inceptionYear.equals(year)) {
                  year = inceptionYear + "-" + year;
              }
  
              // add headers
              if (addHeader) {
                 entries.add(preamble1 + projectName + preamble2);
             } else {
                 entries.add("");
             }
             // fake second entry, we'll look for a real one later
             entries.add(projectName + "\nCopyright " + year + " " + organizationName + "\n");
             entries.add(preamble3 + organizationName + " (" + organizationURL + ").\n");
         }
 
         BufferedReader reader;
         if (encoding != null && !encoding.isEmpty()) {
             reader = new BufferedReader(new InputStreamReader(is, encoding));
         } else {
             reader = new BufferedReader(new InputStreamReader(is));
         }
 
         String line = reader.readLine();
         StringBuilder sb = new StringBuilder();
         Set<String> currentOrg = null;
         int lineCount = 0;
         while (line != null) {
             String trimedLine = line.trim();
 
             if (!trimedLine.startsWith("//")) {
                 if (trimedLine.length() > 0) {
                     if (trimedLine.startsWith("- ")) {
                         // resource-bundle 1.3 mode
                         if (lineCount == 1
                                 && sb.toString().contains("This product includes/uses software(s) developed by")) {
                             currentOrg = organizationEntries.get(sb.toString().trim());
                             if (currentOrg == null) {
                                 currentOrg = new TreeSet<>();
                                 organizationEntries.put(sb.toString().trim(), currentOrg);
                             }
                             sb = new StringBuilder();
                         } else if (sb.length() > 0 && currentOrg != null) {
                             currentOrg.add(sb.toString());
                             sb = new StringBuilder();
                         }
                     }
                     sb.append(line).append("\n");
                     lineCount++;
                 } else {
                     String ent = sb.toString();
                     if (ent.startsWith(projectName) && ent.contains("Copyright ")) {
                         copyright = ent;
                     }
                     if (currentOrg == null) {
                         entries.add(ent);
                     } else {
                         currentOrg.add(ent);
                     }
                     sb = new StringBuilder();
                     lineCount = 0;
                     currentOrg = null;
                 }
             }
 
             line = reader.readLine();
         }
         if (sb.length() > 0) {
             if (currentOrg == null) {
                 entries.add(sb.toString());
             } else {
                 currentOrg.add(sb.toString());
             }
         }
         if (time > this.time) {
             this.time = time;
         }
     }
 
     @Override
     public boolean hasTransformedResource() {
         return true;
     }
 
     @Override
     public void modifyOutputStream(JarOutputStream jos) throws IOException {
         JarEntry jarEntry = new JarEntry(NOTICE_PATH);
         jarEntry.setTime(time);
         jos.putNextEntry(jarEntry);
 
         Writer writer;
         if (encoding != null && !encoding.isEmpty()) {
             writer = new OutputStreamWriter(jos, encoding);
         } else {
             writer = new OutputStreamWriter(jos);
         }
 
         int count = 0;
         for (String line : entries) {
             ++count;
             if (line.equals(copyright) && count != 2) {
                 continue;
             }
 
             if (count == 2 && copyright != null) {
                 writer.write(copyright);
                 writer.write('\n');
             } else {
                 writer.write(line);
                 writer.write('\n');
             }
             if (count == 3) {
                 // do org stuff
                 for (Map.Entry<String, Set<String>> entry : organizationEntries.entrySet()) {
                     writer.write(entry.getKey());
                     writer.write('\n');
                     for (String l : entry.getValue()) {
                         writer.write(l);
                     }
                     writer.write('\n');
                 }
             }
         }
 
         writer.flush();
 
         entries.clear();
     }
 }