/*
    * 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) 2015 Institute for Defense Analyses. All Rights Reserved.
   */
  package org.owasp.dependencycheck.analyzer;
  
  import org.apache.commons.io.FileUtils;
  import org.owasp.dependencycheck.Engine;
  import org.owasp.dependencycheck.analyzer.exception.AnalysisException;
  import org.owasp.dependencycheck.dependency.Confidence;
  import org.owasp.dependencycheck.dependency.Dependency;
  import org.owasp.dependencycheck.dependency.EvidenceCollection;
  import org.owasp.dependencycheck.utils.FileFilterBuilder;
  import org.owasp.dependencycheck.utils.Settings;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.File;
  import java.io.FileFilter;
  import java.io.IOException;
  import java.util.Map;
  import javax.json.Json;
  import javax.json.JsonException;
  import javax.json.JsonObject;
  import javax.json.JsonReader;
  import javax.json.JsonString;
  import javax.json.JsonValue;
  
  /**
   * Used to analyze Node Package Manager (npm) package.json files, and collect information that can be used to determine the
   * associated CPE.
   *
   * @author Dale Visser
   */
  @Experimental
  public class NodePackageAnalyzer extends AbstractFileTypeAnalyzer {
  
      /**
       * The logger.
       */
      private static final Logger LOGGER = LoggerFactory.getLogger(NodePackageAnalyzer.class);
  
      /**
       * The name of the analyzer.
       */
      private static final String ANALYZER_NAME = "Node.js Package Analyzer";
  
      /**
       * The phase that this analyzer is intended to run in.
       */
      private static final AnalysisPhase ANALYSIS_PHASE = AnalysisPhase.INFORMATION_COLLECTION;
  
      /**
       * The file name to scan.
       */
      public static final String PACKAGE_JSON = "package.json";
      /**
       * Filter that detects files named "package.json".
       */
      private static final FileFilter PACKAGE_JSON_FILTER = FileFilterBuilder.newInstance()
              .addFilenames(PACKAGE_JSON).build();
  
      /**
       * Returns the FileFilter
       *
       * @return the FileFilter
       */
      @Override
      protected FileFilter getFileFilter() {
          return PACKAGE_JSON_FILTER;
      }
  
      @Override
      protected void initializeFileTypeAnalyzer() throws Exception {
          // NO-OP
      }
  
      /**
       * Returns the name of the analyzer.
       *
       * @return the name of the analyzer.
       */
      @Override
      public String getName() {
          return ANALYZER_NAME;
      }
 
     /**
      * Returns the phase that the analyzer is intended to run in.
      *
      * @return the phase that the analyzer is intended to run in.
      */
     @Override
     public AnalysisPhase getAnalysisPhase() {
         return ANALYSIS_PHASE;
     }
 
     /**
      * Returns the key used in the properties file to reference the analyzer's enabled property.
      *
      * @return the analyzer's enabled property setting key
      */
     @Override
     protected String getAnalyzerEnabledSettingKey() {
         return Settings.KEYS.ANALYZER_NODE_PACKAGE_ENABLED;
     }
 
     @Override
     protected void analyzeFileType(Dependency dependency, Engine engine)
             throws AnalysisException {
         final File file = dependency.getActualFile();
         JsonReader jsonReader;
         try {
             jsonReader = Json.createReader(FileUtils.openInputStream(file));
         } catch (IOException e) {
             throw new AnalysisException(
                     "Problem occurred while reading dependency file.", e);
         }
         try {
             final JsonObject json = jsonReader.readObject();
             final EvidenceCollection productEvidence = dependency.getProductEvidence();
             final EvidenceCollection vendorEvidence = dependency.getVendorEvidence();
             if (json.containsKey("name")) {
                 final Object value = json.get("name");
                 if (value instanceof JsonString) {
                     final String valueString = ((JsonString) value).getString();
                     productEvidence.addEvidence(PACKAGE_JSON, "name", valueString, Confidence.HIGHEST);
                     vendorEvidence.addEvidence(PACKAGE_JSON, "name_project", String.format("%s_project", valueString), Confidence.LOW);
                 } else {
                     LOGGER.warn("JSON value not string as expected: {}", value);
                 }
             }
             addToEvidence(json, productEvidence, "description");
             addToEvidence(json, vendorEvidence, "author");
             addToEvidence(json, dependency.getVersionEvidence(), "version");
             dependency.setDisplayFileName(String.format("%s/%s", file.getParentFile().getName(), file.getName()));
         } catch (JsonException e) {
             LOGGER.warn("Failed to parse package.json file.", e);
         } finally {
             jsonReader.close();
         }
     }
 
     /**
      * Adds information to an evidence collection from the node json configuration.
      *
      * @param json information from node.js
      * @param collection a set of evidence about a dependency
      * @param key the key to obtain the data from the json information
      */
     private void addToEvidence(JsonObject json, EvidenceCollection collection, String key) {
         if (json.containsKey(key)) {
             final JsonValue value = json.get(key);
             if (value instanceof JsonString) {
                 collection.addEvidence(PACKAGE_JSON, key, ((JsonString) value).getString(), Confidence.HIGHEST);
             } else if (value instanceof JsonObject) {
                 final JsonObject jsonObject = (JsonObject) value;
                 for (final Map.Entry<String, JsonValue> entry : jsonObject.entrySet()) {
                     final String property = entry.getKey();
                     final JsonValue subValue = entry.getValue();
                     if (subValue instanceof JsonString) {
                         collection.addEvidence(PACKAGE_JSON,
                                 String.format("%s.%s", key, property),
                                 ((JsonString) subValue).getString(),
                                 Confidence.HIGHEST);
                     } else {
                         LOGGER.warn("JSON sub-value not string as expected: {}", subValue);
                     }
                 }
             } else {
                 LOGGER.warn("JSON value not string or JSON object as expected: {}", value);
             }
         }
     }
 }