/*
    * 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) 2018 Steve Springett. All Rights Reserved.
   */
  package org.owasp.dependencycheck.data.nodeaudit;
  
  import io.github.jeremylong.openvulnerability.client.nvd.CvssV3;
  import org.json.JSONArray;
  import org.json.JSONObject;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  import org.json.JSONException;
  import org.owasp.dependencycheck.utils.CvssUtil;
  
  /**
   * Parser for NPM Audit API response. This parser is derived from:
   * https://github.com/DependencyTrack/dependency-track/blob/master/src/main/java/org/owasp/dependencytrack/parser/npm/audit/NpmAuditParser.java
   *
   * @author Steve Springett
   */
  public class NpmAuditParser {
  
      /**
       * The logger.
       */
      private static final Logger LOGGER = LoggerFactory.getLogger(NpmAuditParser.class);
  
      /**
       * Parses the JSON response from the NPM Audit API.
       *
       * @param jsonResponse the JSON node to parse
       * @return an AdvisoryResults object
       * @throws org.json.JSONException thrown if the JSON is not of the expected
       * schema
       */
      public List<Advisory> parse(JSONObject jsonResponse) throws JSONException {
          LOGGER.debug("Parsing JSON node");
          final List<Advisory> advisories = new ArrayList<>();
          final JSONObject jsonAdvisories = jsonResponse.getJSONObject("advisories");
          final Iterator<?> keys = jsonAdvisories.keys();
          while (keys.hasNext()) {
              final String key = (String) keys.next();
              final Advisory advisory = parseAdvisory(jsonAdvisories.getJSONObject(key));
              advisories.add(advisory);
          }
          return advisories;
      }
  
      /**
       * Parses the advisory from Node Audit.
       *
       * @param object the JSON object containing the advisory
       * @return the Advisory object
       * @throws org.json.JSONException thrown if the JSON is not of the expected
       * schema
       */
      private Advisory parseAdvisory(JSONObject object) throws JSONException {
          final Advisory advisory = new Advisory();
          advisory.setGhsaId(object.getString("github_advisory_id"));
          advisory.setOverview(object.optString("overview", null));
          advisory.setReferences(object.optString("references", null));
          advisory.setCreated(object.optString("created", null));
          advisory.setUpdated(object.optString("updated", null));
          advisory.setRecommendation(object.optString("recommendation", null));
          advisory.setTitle(object.optString("title", null));
          //advisory.setFoundBy(object.optString("author", null));
          //advisory.setReportedBy(object.optString("author", null));
          advisory.setModuleName(object.optString("module_name", null));
          advisory.setVulnerableVersions(object.optString("vulnerable_versions", null));
          advisory.setPatchedVersions(object.optString("patched_versions", null));
          advisory.setAccess(object.optString("access", null));
          advisory.setSeverity(object.optString("severity", null));
  
          final JSONArray jsonCwes = object.optJSONArray("cwe");
          final List<String> stringCwes = new ArrayList<>();
          if (jsonCwes != null) {
              for (int j = 0; j < jsonCwes.length(); j++) {
                  stringCwes.add(jsonCwes.getString(j));
              }
          }
          advisory.setCwes(stringCwes);
  
         final JSONArray findings = object.optJSONArray("findings");
         for (int i = 0; i < findings.length(); i++) {
             final JSONObject finding = findings.getJSONObject(i);
             final String version = finding.optString("version", null);
             final JSONArray paths = finding.optJSONArray("paths");
             for (int j = 0; j < paths.length(); j++) {
                 final String path = paths.getString(j);
                 if (path != null && path.equals(advisory.getModuleName())) {
                     advisory.setVersion(version);
                 }
             }
         }
 
         final JSONArray jsonCves = object.optJSONArray("cves");
         final List<String> stringCves = new ArrayList<>();
         if (jsonCves != null) {
             for (int j = 0; j < jsonCves.length(); j++) {
                 stringCves.add(jsonCves.getString(j));
             }
             advisory.setCves(stringCves);
         }
         final JSONObject jsonCvss = object.optJSONObject("cvss");
         if (jsonCvss != null) {
             double baseScore = -1.0;
             final String score = jsonCvss.optString("score");
             if (score != null) {
                 try {
                     baseScore = Float.parseFloat(score);
                 } catch (NumberFormatException ignored) {
                     LOGGER.trace("Swallowed NumberFormatException", ignored);
                     baseScore = -1.0f;
                 }
             }
             if (baseScore >= 0.0) {
                 final String vector = jsonCvss.optString("vectorString");
                 if (vector != null && !"null".equals(vector)) {
                     if (vector.startsWith("CVSS:3") && baseScore >= 0.0) {
                         try {
                             final CvssV3 cvss = CvssUtil.vectorToCvssV3(vector, baseScore);
                             advisory.setCvssV3(cvss);
                         } catch (IllegalArgumentException iae) {
                             LOGGER.warn("Invalid CVSS vector format encountered in NPM Audit results '{}': {} ", vector, iae.getMessage());
                         }
                     } else {
                         LOGGER.warn("Unsupported CVSS vector format in NPM Audit results, please file a feature "
                                 + "request at https://github.com/jeremylong/DependencyCheck/issues/new/choose to "
                                 + "support vector format '{}' ", vector);
                     }
                 }
             }
         }
         return advisory;
     }
 }