/*
    * 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 com.github.packageurl.MalformedPackageURLException;
  import com.github.packageurl.PackageURL;
  import com.github.packageurl.PackageURLBuilder;
  import org.owasp.dependencycheck.Engine;
  import org.owasp.dependencycheck.Engine.Mode;
  import org.owasp.dependencycheck.analyzer.exception.AnalysisException;
  import org.owasp.dependencycheck.data.nvd.ecosystem.Ecosystem;
  import org.owasp.dependencycheck.dependency.Confidence;
  import org.owasp.dependencycheck.dependency.Dependency;
  import org.owasp.dependencycheck.dependency.EvidenceType;
  import org.owasp.dependencycheck.dependency.naming.PurlIdentifier;
  import org.owasp.dependencycheck.exception.InitializationException;
  import org.owasp.dependencycheck.utils.Checksum;
  import org.owasp.dependencycheck.utils.FileFilterBuilder;
  import org.owasp.dependencycheck.utils.InvalidSettingException;
  import org.owasp.dependencycheck.utils.Settings;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import javax.annotation.concurrent.ThreadSafe;
  import javax.json.Json;
  import javax.json.JsonException;
  import javax.json.JsonObject;
  import javax.json.JsonReader;
  import javax.json.JsonString;
  import javax.json.JsonValue;
  import java.io.File;
  import java.io.FileFilter;
  import java.io.IOException;
  import java.nio.file.Files;
  import java.nio.file.Paths;
  import java.security.NoSuchAlgorithmException;
  import java.util.Arrays;
  import java.util.List;
  import java.util.Map;
  import java.util.Objects;
  
  /**
   * 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
   */
  @ThreadSafe
  public class NodePackageAnalyzer extends AbstractNpmAnalyzer {
  
      /**
       * The logger.
       */
      private static final Logger LOGGER = LoggerFactory.getLogger(NodePackageAnalyzer.class);
      /**
       * A descriptor for the type of dependencies processed or added by this
       * analyzer.
       */
      public static final String DEPENDENCY_ECOSYSTEM = Ecosystem.NODEJS;
      /**
       * 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";
      /**
       * The file name to scan.
       */
      public static final String PACKAGE_LOCK_JSON = "package-lock.json";
      /**
       * The file name to scan.
       */
      public static final String SHRINKWRAP_JSON = "npm-shrinkwrap.json";
      /**
       * The name of the directory that contains node modules.
       */
      public static final String NODE_MODULES_DIRNAME = "node_modules";
      /**
      * Filter that detects files named "package.json", "package-lock.json", or
      * "npm-shrinkwrap.json".
      */
     private static final FileFilter PACKAGE_JSON_FILTER = FileFilterBuilder.newInstance()
             .addFilenames(PACKAGE_JSON, PACKAGE_LOCK_JSON, SHRINKWRAP_JSON).build();
 
     /**
      * Returns the FileFilter
      *
      * @return the FileFilter
      */
     @Override
     protected FileFilter getFileFilter() {
         return PACKAGE_JSON_FILTER;
     }
 
     /**
      * Performs validation on the configuration to ensure that the correct
      * analyzers are in place.
      *
      * @param engine the dependency-check engine
      * @throws InitializationException thrown if there is a configuration error
      */
     @Override
     protected void prepareFileTypeAnalyzer(Engine engine) throws InitializationException {
         if (engine.getMode() != Mode.EVIDENCE_COLLECTION) {
             try {
                 final Settings settings = engine.getSettings();
                 final String[] tmp = settings.getArray(Settings.KEYS.ECOSYSTEM_SKIP_CPEANALYZER);
                 if (tmp != null) {
                     final List<String> skipEcosystems = Arrays.asList(tmp);
                     if (skipEcosystems.contains(DEPENDENCY_ECOSYSTEM)
                             && !settings.getBoolean(Settings.KEYS.ANALYZER_OSSINDEX_ENABLED)) {
                         if (!settings.getBoolean(Settings.KEYS.ANALYZER_NODE_AUDIT_ENABLED)) {
                             final String msg = "Invalid Configuration: enabling the Node Package Analyzer without "
                                     + "using the Node Audit Analyzer or OSS Index Analyzer is not supported.";
                             throw new InitializationException(msg);
                         } else if (!isNodeAuditEnabled(engine)) {
                             final String msg = "Missing package.lock or npm-shrinkwrap.lock file: Unable to scan a node "
                                     + "project without a package-lock.json or npm-shrinkwrap.json.";
                             throw new InitializationException(msg);
                         }
                     } else if (skipEcosystems.contains(DEPENDENCY_ECOSYSTEM)
                             && !settings.getBoolean(Settings.KEYS.ANALYZER_NODE_AUDIT_ENABLED)) {
                         LOGGER.warn("Using only the OSS Index Analyzer with Node.js can result in many false positives "
                                 + "- please enable the Node Audit Analyzer.");
                     }
                 }
             } catch (InvalidSettingException ex) {
                 throw new InitializationException("Unable to read configuration settings", ex);
             }
         }
     }
 
     /**
      * 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 enabled
      * property for the analyzer.
      *
      * @return the enabled property setting key for the analyzer
      */
     @Override
     protected String getAnalyzerEnabledSettingKey() {
         return Settings.KEYS.ANALYZER_NODE_PACKAGE_ENABLED;
     }
 
     /**
      * Determines if the Node Audit analyzer is enabled.
      *
      * @param engine a reference to the dependency-check engine
      * @return <code>true</code> if the Node Audit Analyzer is enabled;
      * otherwise <code>false</code>
      */
     private boolean isNodeAuditEnabled(Engine engine) {
         for (Analyzer a : engine.getAnalyzers()) {
             if (a instanceof NodeAuditAnalyzer || a instanceof YarnAuditAnalyzer || a instanceof PnpmAuditAnalyzer) {
                 if (a.isEnabled()) {
                     try {
                         ((AbstractNpmAnalyzer) a).prepareFileTypeAnalyzer(engine);
                     } catch (InitializationException ex) {
                         LOGGER.debug("Error initializing the {}", a.getName());
                     }
                 }
                 return a.isEnabled();
             }
         }
         return false;
     }
 
     /**
      * Checks if a package lock file or equivalent exists for the NPM project.
      *
      * @param dependencyFile a reference to the `package.json` file
      * @return <code>true</code> if no lock file is found; otherwise
      * <code>true</code>
      */
     private boolean noLockFileExists(File dependencyFile) {
         final File lock = new File(dependencyFile.getParentFile(), "package-lock.json");
         final File shrinkwrap = new File(dependencyFile.getParentFile(), "npm-shrinkwrap.json");
         final File yarnLock = new File(dependencyFile.getParentFile(), "yarn.lock");
         return !(lock.isFile() || shrinkwrap.isFile() || yarnLock.isFile());
     }
 
     @Override
     protected void analyzeDependency(Dependency dependency, Engine engine) throws AnalysisException {
         final File dependencyFile = dependency.getActualFile();
         if (!dependencyFile.isFile() || dependencyFile.length() == 0 || !shouldProcess(dependencyFile)) {
             return;
         }
         if (isNodeAuditEnabled(engine)
                 && !(PACKAGE_LOCK_JSON.equals(dependency.getFileName()) || SHRINKWRAP_JSON.equals(dependency.getFileName()))) {
             engine.removeDependency(dependency);
         }
         if (noLockFileExists(dependency.getActualFile())) {
             LOGGER.warn("No lock file exists - this will result in false negatives; please run `npm install --package-lock`");
         }
         final File baseDir = dependencyFile.getParentFile();
         if (PACKAGE_JSON.equals(dependency.getFileName())) {
             final File lockfile = new File(baseDir, PACKAGE_LOCK_JSON);
             final File shrinkwrap = new File(baseDir, SHRINKWRAP_JSON);
             if (shrinkwrap.exists() || lockfile.exists()) {
                 return;
             }
         } else if (PACKAGE_LOCK_JSON.equals(dependency.getFileName())) {
             final File shrinkwrap = new File(baseDir, SHRINKWRAP_JSON);
             if (shrinkwrap.exists()) {
                 return;
             }
         }
         final File nodeModules = new File(baseDir, "node_modules");
         if (!nodeModules.isDirectory()) {
             LOGGER.warn("Analyzing `{}` - however, the node_modules directory does not exist. "
                     + "Please run `npm install` prior to running dependency-check", dependencyFile);
             return;
         }
 
         try (JsonReader jsonReader = Json.createReader(Files.newInputStream(dependencyFile.toPath()))) {
             final JsonObject json = jsonReader.readObject();
             final String parentName = json.getString("name", "");
             final String parentVersion = json.getString("version", "");
             if (parentName.isEmpty()) {
                 return;
             }
             dependency.setName(parentName);
             final String parentPackage;
             if (!parentVersion.isEmpty()) {
                 dependency.setVersion(parentVersion);
                 parentPackage = String.format("%s:%s", parentName, parentVersion);
             } else {
                 parentPackage = parentName;
             }
             processDependencies(json, baseDir, dependencyFile, parentPackage, engine);
         } catch (JsonException e) {
             LOGGER.warn("Failed to parse package.json file.", e);
         } catch (IOException e) {
             throw new AnalysisException("Problem occurred while reading dependency file.", e);
         }
     }
 
     /**
      * should process the dependency ? Will return true if you need to skip it .
      * (e.g. dependency can't be read, or if npm audit doesn't handle it)
      *
      * @param name the name of the dependency
      * @param version the version of the dependency
      * @param optional is the dependency optional ?
      * @param fileExist is the package.json available for this file ?
      * @return should you skip this dependency ?
      */
     public static boolean shouldSkipDependency(String name, String version, boolean optional, boolean fileExist) {
         // some package manager can handle alias, yarn for example, but npm doesn't support it
         if (Objects.nonNull(version) && version.startsWith("npm:")) {
             //TODO make this an error that gets logged
             LOGGER.warn("dependency skipped: package.json contain an alias for {} => {} npm audit doesn't "
                     + "support aliases", name, version.replace("npm:", ""));
             return true;
         }
 
         if (optional && !fileExist) {
             LOGGER.warn("dependency skipped: node module {} seems optional and not installed", name);
             return true;
         }
 
         // this seems to produce crash sometimes, I need to tests
         // using a local node_module is not supported by npm audit, it crash
         if (Objects.nonNull(version) && (version.startsWith("file:") || version.matches("^[.~]{0,2}/.*"))) {
             LOGGER.warn("dependency skipped: package.json contain an local node_module for {} seems to be "
                             + "located {} npm audit doesn't support locally referenced modules",
                     name, version);
             return true;
         }
 
         // Don't include package with empty name
         if ("".equals(name)) {
             LOGGER.debug("Empty dependency of package-lock v2+ removed");
             return true;
         }
 
         return false;
     }
 
     /**
      * Checks if the given dependency should be skipped.
      *
      * @param name the name of the dependency to test
      * @param version the version of the dependency to test
      * @return <code>true</code> if the dependency should be skipped; otherwise
      * <code>false</code>
      * @see NodePackageAnalyzer#shouldSkipDependency(java.lang.String,
      * java.lang.String, boolean, boolean)
      */
     public static boolean shouldSkipDependency(String name, String version) {
         return shouldSkipDependency(name, version, false, true);
     }
 
     /**
      * Process the dependencies in the lock file by first parsing its
      * dependencies and then finding the package.json for the module and adding
      * it as a dependency.
      *
      * @param json the data to process
      * @param baseDir the base directory being scanned
      * @param rootFile the root package-lock/npm-shrinkwrap being analyzed
      * @param parentPackage the parent package name of the current node
      * @param engine a reference to the dependency-check engine
      * @throws AnalysisException thrown if there is an exception
      */
     private void processDependencies(JsonObject json, File baseDir, File rootFile,
                                      String parentPackage, Engine engine) throws AnalysisException {
         final boolean skipDev = getSettings().getBoolean(Settings.KEYS.ANALYZER_NODE_PACKAGE_SKIPDEV, false);
         final JsonObject deps;
         final File modulesRoot = new File(rootFile.getParentFile(), "node_modules");
         final int lockJsonVersion = json.containsKey("lockfileVersion") ? json.getInt("lockfileVersion") : 1;
         if (lockJsonVersion >= 2) {
             deps = json.getJsonObject("packages");
         } else if (json.containsKey("dependencies")) {
             deps = json.getJsonObject("dependencies");
         } else {
             deps = null;
         }
 
         if (deps != null) {
             for (Map.Entry<String, JsonValue> entry : deps.entrySet()) {
                 final String pathName = entry.getKey();
                 String name = pathName;
                 File base;
 
                 final int indexOfNodeModule = name.lastIndexOf(NODE_MODULES_DIRNAME + "/");
                 if (indexOfNodeModule >= 0) {
                     name = name.substring(indexOfNodeModule + NODE_MODULES_DIRNAME.length() + 1);
                     base = Paths.get(baseDir.getPath(), pathName).toFile();
                 } else {
                     base = Paths.get(baseDir.getPath(), "node_modules", name).toFile();
                     if (!base.isDirectory()) {
                         final File test = new File(modulesRoot, name);
                         if (test.isDirectory()) {
                             base = test;
                         }
                     }
                 }
 
                 final String version;
                 boolean optional = false;
                 boolean isDev = false;
 
                 final File f = new File(base, PACKAGE_JSON);
                 JsonObject jo = null;
 
                 if (entry.getValue() instanceof JsonObject) {
                     jo = (JsonObject) entry.getValue();
 
                     // Ignore/skip linked entries (as they don't have "version" and
                     // later logic will crash)
                     if (jo.getBoolean("link", false)) {
                         LOGGER.warn("Skipping `" + name + "` because it is a link dependency");
                         continue;
                     }
 
                     version = jo.getString("version", "");
                     optional = jo.getBoolean("optional", false);
                     isDev = jo.getBoolean("dev", false);
                 } else {
                     version = ((JsonString) entry.getValue()).getString();
                 }
 
                 if ((isDev && skipDev) || shouldSkipDependency(name, version, optional, f.exists())) {
                     continue;
                 }
 
                 if (null != jo && jo.containsKey("dependencies")) {
                     final String subPackageName = String.format("%s/%s:%s", parentPackage, name, version);
                     processDependencies(jo, base, rootFile, subPackageName, engine);
                 }
 
                 String ref = "";
                 final int slash = parentPackage.indexOf("/");
                 if (slash > 0) {
                     ref = parentPackage.substring(slash + 1);
                 }
                 final Dependency child = new Dependency(new File(rootFile + "?" + ref + "/" + name + ":" + version), true);
                 child.addProjectReference(parentPackage);
                 child.setEcosystem(DEPENDENCY_ECOSYSTEM);
 
                 if (f.exists()) {
                     try {
                         //TODO - we should use the integrity value instead of calculating the SHA1/MD5
                         child.setMd5sum(Checksum.getMD5Checksum(f));
                         child.setSha1sum(Checksum.getSHA1Checksum(f));
                         child.setSha256sum(Checksum.getSHA256Checksum(f));
                     } catch (IOException | NoSuchAlgorithmException ex) {
                         LOGGER.debug("Error setting hashes:" + ex.getMessage(), ex);
                     }
                     try (JsonReader jr = Json.createReader(Files.newInputStream(f.toPath()))) {
                         final JsonObject childJson = jr.readObject();
                         gatherEvidence(childJson, child);
                     } catch (JsonException e) {
                         LOGGER.warn("Failed to parse package.json file from dependency.", e);
                     } catch (IOException e) {
                         throw new AnalysisException("Problem occurred while reading dependency file.", e);
                     }
                 } else {
                     LOGGER.warn("Unable to find node module: {}", f);
                     //TODO - we should use the integrity value instead of calculating the SHA1/MD5
                     child.setSha1sum(Checksum.getSHA1Checksum(String.format("%s:%s", name, version)));
                     child.setSha256sum(Checksum.getSHA256Checksum(String.format("%s:%s", name, version)));
                     child.setMd5sum(Checksum.getMD5Checksum(String.format("%s:%s", name, version)));
                     child.addEvidence(EvidenceType.VENDOR, rootFile.getName(), "name", name, Confidence.HIGHEST);
                     child.addEvidence(EvidenceType.PRODUCT, rootFile.getName(), "name", name, Confidence.HIGHEST);
                     child.addEvidence(EvidenceType.VERSION, rootFile.getName(), "version", version, Confidence.HIGHEST);
                     child.setName(name);
                     child.setVersion(version);
                     final String packagePath = String.format("%s:%s", name, version);
                     child.setDisplayFileName(packagePath);
                     child.setPackagePath(packagePath);
                     try {
                         final PackageURL purl = PackageURLBuilder.aPackageURL().withType("npm").withName(name).withVersion(version).build();
                         final PurlIdentifier id = new PurlIdentifier(purl, Confidence.HIGHEST);
                         child.addSoftwareIdentifier(id);
                     } catch (MalformedPackageURLException ex) {
                         LOGGER.debug("Unable to build package url for `" + packagePath + "`", ex);
                     }
                 }
                 synchronized (this) {
                     final Dependency existing = findDependency(engine, name, version);
                     if (existing != null) {
                         if (existing.isVirtual()) {
                             DependencyMergingAnalyzer.mergeDependencies(child, existing, null);
                             engine.removeDependency(existing);
                             engine.addDependency(child);
                         } else {
                             DependencyBundlingAnalyzer.mergeDependencies(existing, child, null);
                         }
                     } else {
                         engine.addDependency(child);
                     }
                 }
             }
         }
     }
 }