/*
    * This file is part of dependency-check-ant.
    *
    * 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) 2021 The OWASP Foundation. All Rights Reserved.
   */
  package org.owasp.dependencycheck.analyzer;
  
  import org.apache.commons.collections4.MultiValuedMap;
  import org.apache.commons.collections4.multimap.HashSetValuedHashMap;
  import org.apache.commons.io.IOUtils;
  import org.apache.commons.lang3.StringUtils;
  import org.json.JSONException;
  import org.json.JSONObject;
  import org.owasp.dependencycheck.Engine;
  import org.owasp.dependencycheck.analyzer.exception.AnalysisException;
  import org.owasp.dependencycheck.analyzer.exception.SearchException;
  import org.owasp.dependencycheck.analyzer.exception.UnexpectedAnalysisException;
  import org.owasp.dependencycheck.data.nodeaudit.Advisory;
  import org.owasp.dependencycheck.data.nodeaudit.NpmPayloadBuilder;
  import org.owasp.dependencycheck.dependency.Dependency;
  import org.owasp.dependencycheck.exception.InitializationException;
  import org.owasp.dependencycheck.utils.FileFilterBuilder;
  import org.owasp.dependencycheck.utils.Settings;
  import org.owasp.dependencycheck.utils.URLConnectionFailureException;
  import org.owasp.dependencycheck.utils.processing.ProcessReader;
  import org.semver4j.Semver;
  import org.semver4j.SemverException;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import us.springett.parsers.cpe.exceptions.CpeValidationException;
  
  import javax.annotation.concurrent.ThreadSafe;
  import jakarta.json.Json;
  import jakarta.json.JsonException;
  import jakarta.json.JsonObject;
  import jakarta.json.JsonReader;
  import java.io.File;
  import java.io.FileFilter;
  import java.io.IOException;
  import java.nio.charset.StandardCharsets;
  import java.nio.file.Files;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.List;
  import java.util.stream.Stream;
  
  import static org.owasp.dependencycheck.utils.FileUtils.existsWithContent;
  
  @ThreadSafe
  public class YarnAuditAnalyzer extends AbstractNpmAnalyzer {
  
      /**
       * The Logger for use throughout the class.
       */
      private static final Logger LOGGER = LoggerFactory.getLogger(YarnAuditAnalyzer.class);
  
      /**
       * The major version of the Yarn Classic CLI.
       */
      private static final int YARN_CLASSIC_MAJOR_VERSION = 1;
  
      /**
       * The file name to scan.
       */
      public static final String YARN_PACKAGE_LOCK = "yarn.lock";
  
      /**
       * Filter that detects files named "yarn.lock"
       */
      private static final FileFilter LOCK_FILE_FILTER = FileFilterBuilder.newInstance()
              .addFilenames(YARN_PACKAGE_LOCK).build();
  
      /**
       * An expected error from `yarn audit --offline --verbose --json` that will
       * be ignored.
       */
      private static final String EXPECTED_ERROR = "{\"type\":\"error\",\"data\":\"Can't make a request in "
              + "offline mode (\\\"https://registry.yarnpkg.com/-/npm/v1/security/audits\\\")\"}\n";
  
      /**
       * The path to the `yarn` executable.
       */
      private String yarnPath;
  
      @Override
      protected String getAnalyzerEnabledSettingKey() {
          return Settings.KEYS.ANALYZER_YARN_AUDIT_ENABLED;
     }
 
     @Override
     protected FileFilter getFileFilter() {
         return LOCK_FILE_FILTER;
     }
 
     @Override
     public String getName() {
         return "Yarn Audit Analyzer";
     }
 
     @Override
     public AnalysisPhase getAnalysisPhase() {
         return AnalysisPhase.FINDING_ANALYSIS;
     }
 
     /**
      * Determines the Yarn major version implied by the metadata in the passed directory.
      *
      * @param dependencyDirectory The directory containing the lockfile and/or package.json
      * @return the yarn version detected
      */
     private Semver getYarnVersion(File dependencyDirectory) {
         List<String> args = List.of(yarnPath, "--version");
         final ProcessBuilder builder = new ProcessBuilder(args);
         builder.directory(dependencyDirectory);
         try {
             final Process process = builder.start();
             try (ProcessReader processReader = new ProcessReader(process)) {
                 processReader.readAll();
                 final int exitValue = process.waitFor();
                 final var yarnVersion = StringUtils.trimToEmpty(processReader.getOutput());
                 if (exitValue != 0) {
                     throw new IllegalStateException(String.format("Unable to determine yarn version, unexpected response (exit value %s, output: %s, error: %s)", exitValue, yarnVersion, processReader.getError()));
                 }
                 if (StringUtils.isBlank(yarnVersion)) {
                     throw new IllegalStateException("Unable to determine yarn version, blank output.");
                 }
                 return Semver.coerce(yarnVersion);
             }
         }  catch (SemverException e) {
             throw new IllegalStateException("Invalid version string format", e);
         } catch (Exception ex) {
             throw new IllegalStateException("Unable to determine yarn version.", ex);
         }
     }
 
 
     /**
      * Initializes the analyzer once before any analysis is performed.
      *
      * @param engine a reference to the dependency-check engine
      * @throws InitializationException if there's an error during initialization
      */
     @Override
     protected void prepareFileTypeAnalyzer(Engine engine) throws InitializationException {
         super.prepareFileTypeAnalyzer(engine);
         if (!isEnabled()) {
             LOGGER.debug("{} Analyzer is disabled skipping yarn executable check", getName());
             return;
         }
         try {
             cacheYarnCommandPath();
             getYarnVersion(new File("."));
         } catch (Exception ex){
             this.setEnabled(false);
             LOGGER.warn("The {} has been disabled after failing to find yarn. Yarn executable was not " +
                     "found or received a non-zero exit value: {}", getName(), ex.getMessage());
             throw new InitializationException("Unable to determine yarn executable to use.", ex);
         }
     }
 
     /**
      * Attempts to determine and cache the path to `yarn`.
      */
     private void cacheYarnCommandPath() {
         String value = getSettings().getString(Settings.KEYS.ANALYZER_YARN_PATH);
         if (value == null || value.isBlank()) {
             value = "yarn";
         } else {
             File fileValue = new File(value);
             if (fileValue.isFile()) {
                 value = fileValue.getAbsolutePath();
             } else {
                 LOGGER.warn("Provided path to `yarn` executable is invalid; defaulting to `yarn`.");
                 value = "yarn";
             }
         }
 
         yarnPath = value;
     }
 
     /**
      * Workaround 64k limitation of InputStream, redirect stdout to a file that we will read later
      * instead of reading directly stdout from Process's InputStream which is topped at 64k
      *
      * @param builder a reference to the process builder
      * @return returns the standard out from the process
      */
     private String startAndReadStdoutToString(ProcessBuilder builder) throws AnalysisException {
         try {
             final File tmpFile = getSettings().getTempFile("yarn_audit", "json");
             builder.redirectOutput(tmpFile);
             final Process process = builder.start();
             try (ProcessReader processReader = new ProcessReader(process)) {
                 processReader.readAll();
                 final String errOutput = processReader.getError();
 
                 if (!StringUtils.isBlank(errOutput) && !EXPECTED_ERROR.equals(errOutput)) {
                     LOGGER.debug("Process Error Out: {}", errOutput);
                     LOGGER.debug("Process Out: {}", processReader.getOutput());
                 }
                 return Files.readString(tmpFile.toPath());
             } catch (InterruptedException ex) {
                 Thread.currentThread().interrupt();
                 throw new AnalysisException("Yarn audit process was interrupted.", ex);
             }
         } catch (IOException ioe) {
             throw new AnalysisException("yarn audit failure; this error can be ignored if you are not analyzing projects with a yarn lockfile.", ioe);
         }
     }
 
     /**
      * Analyzes the yarn lock file to determine vulnerable dependencies. Uses
      * yarn audit --offline to generate the payload to be sent to the NPM API.
      *
      * @param dependency the yarn lock file
      * @param engine the analysis engine
      * @throws AnalysisException thrown if there is an error analyzing the file
      */
     @Override
     protected void analyzeDependency(Dependency dependency, Engine engine) throws AnalysisException {
         if (dependency.getDisplayFileName().equals(dependency.getFileName())) {
             engine.removeDependency(dependency);
         }
         final File packageLock = dependency.getActualFile();
         if (!existsWithContent(packageLock) || !shouldProcess(packageLock)) {
             return;
         }
         File dependencyDirectory = getDependencyDirectory(packageLock);
         final var yarnVersion = getYarnVersion(dependencyDirectory);
         final List<Advisory> advisories;
         final MultiValuedMap<String, String> dependencyMap = new HashSetValuedHashMap<>();
         if (YARN_CLASSIC_MAJOR_VERSION < yarnVersion.getMajor()) {
             LOGGER.info("Analyzing using Yarn Berry ({}) audit for {}", yarnVersion, dependency.getActualFilePath());
             advisories = analyzePackageWithYarnBerry(dependency);
         } else {
             LOGGER.info("Analyzing using Yarn Classic ({}) audit for {}", yarnVersion, dependency.getActualFilePath());
             advisories = analyzePackageWithYarnClassic(packageLock, dependency, dependencyMap);
         }
         try {
             processResults(advisories, engine, dependency, dependencyMap);
         } catch (CpeValidationException ex) {
             throw new UnexpectedAnalysisException(ex);
         }
     }
 
     private JsonObject fetchYarnAuditJson(File dependencyDirectory, boolean skipDevDependencies) throws AnalysisException {
         final List<String> args = new ArrayList<>();
         args.add(yarnPath);
         args.add("audit");
         //offline audit is not supported - but the audit request is generated in the verbose output
         args.add("--offline");
         if (skipDevDependencies) {
             args.add("--groups");
             args.add("dependencies");
         }
         args.add("--json");
         args.add("--verbose");
         final ProcessBuilder builder = new ProcessBuilder(args);
         builder.directory(dependencyDirectory);
         LOGGER.debug("Launching: {}", args);
 
         final String verboseJson = startAndReadStdoutToString(builder);
         final String auditRequestJson = Arrays.stream(verboseJson.split("\n"))
                 .filter(line -> line.contains("Audit Request"))
                 .findFirst()
                 .orElseThrow(() -> new AnalysisException("No results from Yarn Classic (offline step) - possibly trying to use classic analyzer on Yarn Berry lockfile"));
         String auditRequest;
         try (JsonReader reader = Json.createReader(IOUtils.toInputStream(auditRequestJson, StandardCharsets.UTF_8))) {
             final JsonObject jsonObject = reader.readObject();
             auditRequest = jsonObject.getString("data");
             auditRequest = auditRequest.substring(15);
         }
         LOGGER.debug("Audit Request: {}", auditRequest);
 
         return Json.createReader(IOUtils.toInputStream(auditRequest, StandardCharsets.UTF_8)).readObject();
     }
 
     private static File getDependencyDirectory(File lockFile) {
         final File folder = lockFile.getParentFile();
         if (!folder.isDirectory()) {
             throw new IllegalArgumentException(String.format("%s should have been a directory.", folder.getAbsolutePath()));
         }
         return folder;
     }
 
     /**
      * Analyzes the package and yarn lock files by extracting dependency
      * information, creating a payload to submit to the npm audit API,
      * submitting the payload, and returning the identified advisories.
      *
      * @param lockFile a reference to the package-lock.json
      * @param dependency a reference to the dependency-object for the yarn.lock
      * @param dependencyMap a collection of module/version pairs; during
      * creation of the payload the dependency map is populated with the
      * module/version information.
      * @return a list of advisories
      * @throws AnalysisException thrown when there is an error creating or
      * submitting the npm audit API payload
      */
     private List<Advisory> analyzePackageWithYarnClassic(final File lockFile, Dependency dependency,
                                                          MultiValuedMap<String, String> dependencyMap)
             throws AnalysisException {
         try {
             final boolean skipDevDependencies = getSettings().getBoolean(Settings.KEYS.ANALYZER_NODE_AUDIT_SKIPDEV, false);
             // Retrieves the contents of package-lock.json from the Dependency
             final JsonObject lockJson = fetchYarnAuditJson(getDependencyDirectory(lockFile), skipDevDependencies);
             // Retrieves the contents of package-lock.json from the Dependency
             final JsonObject packageJson;
             try (JsonReader packageReader = Json.createReader(Files.newInputStream(lockFile.getParentFile().toPath().resolve("package.json")))) {
                 packageJson = packageReader.readObject();
             }
             // Modify the payload to meet the NPM Audit API requirements
             final JsonObject payload = NpmPayloadBuilder.build(lockJson, packageJson, dependencyMap, skipDevDependencies);
 
             // Submits the package payload to the nsp check service
             return getSearcher().submitPackage(payload);
 
         } catch (URLConnectionFailureException e) {
             this.setEnabled(false);
             throw new AnalysisException("Failed to connect to the NPM Audit API (YarnAuditAnalyzer); the analyzer "
                     + "is being disabled and may result in false negatives.", e);
         } catch (IOException e) {
             LOGGER.debug("Error reading dependency or connecting to NPM Audit API", e);
             this.setEnabled(false);
             throw new AnalysisException("Failed to read results from the NPM Audit API (YarnAuditAnalyzer); "
                     + "the analyzer is being disabled and may result in false negatives.", e);
         } catch (JsonException e) {
             throw new AnalysisException(String.format("Failed to parse %s file from the NPM Audit API "
                     + "(YarnAuditAnalyzer).", lockFile.getPath()), e);
         } catch (SearchException ex) {
             LOGGER.error("YarnAuditAnalyzer failed on {}", dependency.getActualFilePath());
             throw ex;
         }
     }
 
     private List<JSONObject> fetchYarnAdvisories(Dependency dependency, boolean skipDevDependencies) throws AnalysisException {
         final List<String> args = new ArrayList<>();
 
         args.add(yarnPath);
         args.add("npm");
         args.add("audit");
         if (skipDevDependencies) {
             args.add("--environment");
             args.add("production");
         }
         args.add("--all");
         args.add("--recursive");
         args.add("--no-deprecations");
         args.add("--json");
         final ProcessBuilder builder = new ProcessBuilder(args);
         builder.directory(getDependencyDirectory(dependency.getActualFile()));
 
         final String advisoriesJsons = startAndReadStdoutToString(builder);
 
         LOGGER.debug("Advisories JSON: {}", advisoriesJsons);
         final String[] advisoriesJsonArray = Stream.of(advisoriesJsons.split("\n"))
                 .filter(s -> !s.isBlank())
                 .toArray(String[]::new);
         try {
             final List<JSONObject> advisories = new ArrayList<>();
             for (String advisoriesJson : advisoriesJsonArray) {
                 advisories.add(new JSONObject(advisoriesJson));
             }
 
             return advisories;
         } catch (JSONException e) {
             throw new AnalysisException("Failed to parse the response from NPM Audit API "
                     + "(YarnBerryAuditAnalyzer).", e);
         }
     }
 
     /**
      * Analyzes the package and yarn lock files by calling yarn npm audit and returning the identified advisories.
      *
      * @param dependency a reference to the dependency-object for the yarn.lock
      * @return a list of advisories
      */
     private List<Advisory> analyzePackageWithYarnBerry(Dependency dependency) throws AnalysisException {
         try {
             final var skipDevDependencies = getSettings().getBoolean(Settings.KEYS.ANALYZER_NODE_AUDIT_SKIPDEV, false);
             final var advisoryJsons = fetchYarnAdvisories(dependency, skipDevDependencies);
             return parseAdvisoryJsons(advisoryJsons);
         } catch (JSONException e) {
             throw new AnalysisException("Failed to parse the response from NPM Audit API "
                     + "(YarnBerryAuditAnalyzer).", e);
         } catch (SearchException ex) {
             LOGGER.error("YarnBerryAuditAnalyzer failed on {}", dependency.getActualFilePath());
             throw ex;
         }
     }
 
     private static List<Advisory> parseAdvisoryJsons(List<JSONObject> advisoryJsons) throws JSONException {
         final List<Advisory> advisories = new ArrayList<>();
         for (JSONObject advisoryJson : advisoryJsons) {
             final var advisory = new Advisory();
             final var object = advisoryJson.getJSONObject("children");
             final var moduleName = advisoryJson.optString("value", null);
             final var id = object.get("ID");
             final var url = object.optString("URL", null);
             final var ghsaId = extractGhsaId(url);
             final var issue = object.optString("Issue", null);
             final var severity = object.optString("Severity", null);
             final var vulnerableVersions = object.optString("Vulnerable Versions", null);
             final var treeVersions = object.optJSONArray("Tree Versions");
             final var treeVersionsLength = treeVersions == null ? 0 : treeVersions.length();
             final var versions = new ArrayList<String>();
             for (int i = 0; i < treeVersionsLength; i++) {
                 versions.add(treeVersions.getString(i));
             }
             if (versions.isEmpty()) {
                 versions.add(null);
             }
             for (String version : versions) {
                 advisory.setGhsaId(ghsaId);
                 advisory.setTitle(issue);
                 advisory.setOverview("URL:" + url + "ID: " + id);
                 advisory.setSeverity(severity);
                 advisory.setVulnerableVersions(vulnerableVersions);
                 advisory.setModuleName(moduleName);
                 advisory.setVersion(version);
                 advisory.setCwes(new ArrayList<>());
                 advisories.add(advisory);
             }
         }
         return advisories;
     }
 
     private static String extractGhsaId(String url) {
         if (url == null || url.isEmpty()) {
             return null;
         }
         final int lastSlashIndex = url.lastIndexOf('/');
         if (lastSlashIndex == -1 || lastSlashIndex == url.length() - 1) {
             return null;
         }
         return url.substring(lastSlashIndex + 1);
     }
 }