/*
    * This file is part of dependency-check-core.
    *
    * Licensed 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.
   *
   * Copyright (c) 2013 Jeremy Long. All Rights Reserved.
   */
  package org.owasp.dependencycheck.data.update.nvd.api;
  
  import com.fasterxml.jackson.core.JsonParser;
  import com.fasterxml.jackson.core.JsonToken;
  import com.fasterxml.jackson.databind.ObjectMapper;
  import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
  import io.github.jeremylong.openvulnerability.client.nvd.DefCveItem;
  
  import java.io.IOException;
  import java.io.InputStream;
  
  public class JsonArrayCveItemSource implements CveItemSource<DefCveItem> {
  
      /**
       * The object mapper.
       */
      private final ObjectMapper mapper;
      /**
       * The input stream.
       */
      private final InputStream inputStream;
      /**
       * The JSON parser.
       */
      private final JsonParser jsonParser;
      /**
       * The current item.
       */
      private DefCveItem currentItem;
      /**
       * The next item.
       */
      private DefCveItem nextItem;
  
      /**
       * Constructs a new Item Source.
       *
       * @param inputStream the input stream to read from
       * @throws IOException thrown if there is a problem reading from the input
       * stream
       */
      public JsonArrayCveItemSource(InputStream inputStream) throws IOException {
          mapper = new ObjectMapper();
          mapper.registerModule(new JavaTimeModule());
          this.inputStream = inputStream;
          jsonParser = mapper.getFactory().createParser(inputStream);
  
          if (jsonParser.nextToken() == JsonToken.START_ARRAY) {
              nextItem = readItem(jsonParser);
          }
      }
  
      @Override
      public void close() throws Exception {
          if (jsonParser != null) {
              try {
                  jsonParser.close();
              } catch (IOException ex) {
                  //ignore
              }
          }
          if (inputStream != null) {
              try {
                  inputStream.close();
              } catch (IOException ex) {
                  //ignore
              }
          }
      }
  
      @Override
      public boolean hasNext() {
          return nextItem != null;
      }
  
      @Override
      public DefCveItem next() throws IOException {
          currentItem = nextItem;
          nextItem = readItem(jsonParser);
          return currentItem;
      }
  
     private DefCveItem readItem(JsonParser jsonParser) throws IOException {
         if (jsonParser.nextToken() == JsonToken.START_OBJECT) {
             return mapper.readValue(jsonParser, DefCveItem.class);
         }
         return null;
     }
 }