/*
    * 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 Jeremy Long. All Rights Reserved.
   */
  package org.owasp.dependencycheck.data.update;
  
  import org.jspecify.annotations.NonNull;
  import org.owasp.dependencycheck.Engine;
  import org.owasp.dependencycheck.data.update.exception.UpdateException;
  import org.owasp.dependencycheck.exception.WriteLockException;
  import org.owasp.dependencycheck.utils.Downloader;
  import org.owasp.dependencycheck.utils.InvalidSettingException;
  import org.owasp.dependencycheck.utils.ResourceNotFoundException;
  import org.owasp.dependencycheck.utils.Settings;
  import org.owasp.dependencycheck.utils.TooManyRequestsException;
  import org.owasp.dependencycheck.utils.WriteLock;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import javax.annotation.concurrent.ThreadSafe;
  import java.io.File;
  import java.io.IOException;
  import java.net.MalformedURLException;
  import java.net.URL;
  import java.time.Duration;
  
  import static org.owasp.dependencycheck.utils.FileUtils.existsWithContent;
  
  /**
   * Downloads a local copy of the RetireJS repository.
   *
   * @author Jeremy Long
   */
  @ThreadSafe
  public class RetireJSDataSource extends LocalDataSource {
      /**
       * The default URL to the RetireJS JavaScript repository.
       */
      private static final String DEFAULT_JS_URL = "https://raw.githubusercontent.com/Retirejs/retire.js/master/repository/jsrepository.json";
      /**
       * Static logger.
       */
      private static final Logger LOGGER = LoggerFactory.getLogger(RetireJSDataSource.class);
      /**
       * The configured settings.
       */
      private Settings settings;
  
      /**
       * Constructs a new engine version check utility.
       */
      public RetireJSDataSource() {
      }
  
      /**
       * Downloads the current RetireJS data source.
       *
       * @param engine a reference to the ODC Engine
       * @return returns false as no updates are made to the database
       * @throws UpdateException thrown if the update failed
       */
      @Override
      public boolean update(Engine engine) throws UpdateException {
          this.settings = engine.getSettings();
          final URL url = validatedUrl();
          final File repoFile = validatedRepoFileFrom(url);
          if (isEnabled() && shouldUpdateFromRemote(repoFile)) {
              LOGGER.debug("Begin RetireJS Update");
              initializeRetireJsRepo(settings, url, repoFile);
              saveLastUpdated(repoFile);
          }
          return false;
      }
  
      private @NonNull URL validatedUrl() throws UpdateException {
          final String configuredUrl = settings.getString(Settings.KEYS.ANALYZER_RETIREJS_REPO_JS_URL, DEFAULT_JS_URL);
          try {
              return new URL(configuredUrl);
          } catch (MalformedURLException ex) {
              throw new UpdateException(String.format("Invalid URL for RetireJS repository (%s)", configuredUrl), ex);
          }
      }
  
      public @NonNull File validatedRepoFile() throws UpdateException {
          return validatedRepoFileFrom(validatedUrl());
      }
 
     private @NonNull File validatedRepoFileFrom(URL url) throws UpdateException {
         try {
             String fileName = new File(url.getPath()).getName();
             if (fileName.isBlank()) {
                 throw new InvalidSettingException("RetireJS URL must imply a filename.");
             }
             return new File(settings.getDataDirectory(), fileName);
         } catch (IOException ex) {
             throw new UpdateException("Unable to determine the local location to cache RetireJS repo", ex);
         }
     }
 
     private boolean isEnabled() {
         return settings.getBoolean(Settings.KEYS.ANALYZER_RETIREJS_ENABLED, true);
     }
 
     private boolean shouldUpdateFromRemote(File repoFile) {
         boolean forceupdate = settings.getBoolean(Settings.KEYS.ANALYZER_RETIREJS_FORCEUPDATE, false);
         boolean autoupdate = settings.getBoolean(Settings.KEYS.AUTO_UPDATE, true);
         Duration validFor = Duration.ofHours(settings.getInt(Settings.KEYS.ANALYZER_RETIREJS_REPO_VALID_FOR_HOURS, 24));
         return forceupdate || !existsWithContent(repoFile) || (autoupdate && isStale(repoFile, validFor));
     }
 
     /**
      * Initializes the local RetireJS repository
      *
      * @param settings a reference to the dependency-check settings
      * @param repoUrl the URL to the RetireJS repository to use
      * @param repoFile the filename to use for the RetireJS repository
      * @throws UpdateException thrown if there is an exception during initialization
      */
     @SuppressWarnings("try")
     private void initializeRetireJsRepo(Settings settings, URL repoUrl, File repoFile) throws UpdateException {
         try (WriteLock lock = new WriteLock(settings, true, repoFile.getName() + ".lock")) {
             LOGGER.debug("RetireJS Repo URL: {}", repoUrl.toExternalForm());
             Downloader.getInstance().fetchFile(repoUrl, repoFile);
         } catch (IOException | TooManyRequestsException | ResourceNotFoundException | WriteLockException ex) {
             throw new UpdateException("Failed to initialize the RetireJS repo", ex);
         }
     }
 
     @Override
     @SuppressWarnings("try")
     public boolean purge(Engine engine) {
         this.settings = engine.getSettings();
         boolean result = true;
         try {
             final File dataDir = engine.getSettings().getDataDirectory();
             final URL repoUrl = new URL(engine.getSettings().getString(Settings.KEYS.ANALYZER_RETIREJS_REPO_JS_URL, DEFAULT_JS_URL));
             final String filename = repoUrl.getFile().substring(repoUrl.getFile().lastIndexOf("/") + 1);
             final File repo = new File(dataDir, filename);
             if (repo.exists()) {
                 try (WriteLock lock = new WriteLock(settings, true, filename + ".lock")) {
                     if (repo.delete()) {
                         LOGGER.info("RetireJS repo removed successfully");
                     } else {
                         LOGGER.error("Unable to delete '{}'; please delete the file manually", repo.getAbsolutePath());
                         result = false;
                     }
                 }
             }
         } catch (WriteLockException | IOException ex) {
             LOGGER.error("Unable to delete the RetireJS repo - invalid configuration");
             result = false;
         }
         return result;
     }
 }