/*
    * 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.search.backend.remoterepository.extractor;
  
  import java.util.List;
  
  import org.apache.maven.search.api.Record;
  import org.apache.maven.search.backend.remoterepository.Context;
  import org.apache.maven.search.backend.remoterepository.RecordFactory;
  import org.apache.maven.search.backend.remoterepository.ResponseExtractor;
  import org.jsoup.nodes.Document;
  import org.jsoup.nodes.Element;
  
  /**
   * A support class for extractors.
   */
  public abstract class ResponseExtractorSupport implements ResponseExtractor {
      protected boolean isChecksum(String name) {
          return name.endsWith(".sha1") || name.endsWith(".md5") || name.endsWith(".sha256") || name.endsWith(".sha512");
      }
  
      protected boolean isSignature(String name) {
          return name.endsWith(".asc") || name.endsWith(".sigstore");
      }
  
      protected boolean isMetadata(String name) {
          return name.equals("maven-metadata.xml");
      }
  
      /**
       * Returns {@code true} if the name is not empty, not directory special (".."), is not metadata
       * is not signature and is not checksum. Hence, it should be a name of interest.
       */
      protected boolean accept(String name) {
          return name != null
                  && !name.isEmpty()
                  && !name.contains("..")
                  && !isMetadata(name)
                  && !isSignature(name)
                  && !isChecksum(name);
      }
  
      /**
       * This is Maven metadata parsing, is NOT remote end specific, unlike HTML parsing.
       */
      @Override
      public int populateGA(Context context, Document document, RecordFactory recordFactory, List<Record> page) {
          // Maven Metadata XML like this one:
          // https://repo.maven.apache.org/maven2/org/apache/maven/indexer/search-api/maven-metadata.xml
          Element metadata = document.getElementsByTag("metadata").first();
          if (metadata != null) {
              Element versioning = metadata.getElementsByTag("versioning").first();
              if (versioning != null) {
                  Element versions = versioning.getElementsByTag("versions").first();
                  if (versions != null) {
                      for (Element version : versions.getElementsByTag("version")) {
                          page.add(recordFactory.create(
                                  context.getGroupId(), context.getArtifactId(), version.text(), null, null, null));
                      }
                  }
              }
          }
          return page.size();
      }
  
      /**
       * Processes extracted "name" extracted by {@link #populateGAV(Context, Document, RecordFactory, List)} method.
       */
      protected void populateGAVName(Context context, String name, RecordFactory recordFactory, List<Record> page) {
          if (accept(name)) {
              if (name.startsWith(context.getArtifactId())) {
                  name = name.substring(context.getArtifactId().length() + 1);
                  if (name.startsWith(context.getVersion())) {
                      name = name.substring(context.getVersion().length() + 1);
                      String ext = null;
                      String classifier = null;
                      if (name.contains(".")) {
                          while (name.contains(".")) {
                              if (ext == null) {
                                  ext = name.substring(name.lastIndexOf('.') + 1);
                              } else {
                                  ext = name.substring(name.lastIndexOf('.') + 1) + "." + ext;
                              }
                             name = name.substring(0, name.lastIndexOf('.'));
                         }
                         classifier = name.isEmpty() ? null : name;
                     } else {
                         ext = name;
                     }
                     page.add(recordFactory.create(
                             context.getGroupId(),
                             context.getArtifactId(),
                             context.getVersion(),
                             classifier,
                             ext,
                             null));
                 }
             }
         }
     }
 }