/*
    * 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) 2019 Jeremy Long. All Rights Reserved.
   */
  package org.owasp.dependencycheck.data.cache;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.List;
  import java.util.Properties;
  import org.apache.commons.jcs3.JCS;
  import org.apache.commons.jcs3.access.CacheAccess;
  import org.apache.commons.jcs3.access.exception.CacheException;
  import org.apache.commons.jcs3.engine.CompositeCacheAttributes;
  import org.apache.commons.jcs3.engine.behavior.ICompositeCacheAttributes;
  import org.owasp.dependencycheck.data.nexus.MavenArtifact;
  import org.owasp.dependencycheck.data.nodeaudit.Advisory;
  import org.owasp.dependencycheck.utils.FileUtils;
  import org.owasp.dependencycheck.utils.Settings;
  import org.owasp.dependencycheck.xml.pom.Model;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Factory to instantiate cache repositories.
   *
   * @author Jeremy Long
   */
  public class DataCacheFactory {
  
      /**
       * The logger.
       */
      private static final Logger LOGGER = LoggerFactory.getLogger(DataCacheFactory.class);
      /**
       * The cache directory.
       */
      private static final String CACHE_DIRECTORY = "cache";
      /**
       * The cache properties.
       */
      private static final String CACHE_PROPERTIES = "dependencycheck-cache.properties";
      /**
       * Whether or not JCS has been initialized.
       */
      private static Boolean initialized = false;
  
      /**
       * The types of caches that can be instantiated.
       */
      private enum CacheType {
          /**
           * Used to store node audit analysis.
           */
          NODEAUDIT,
          /**
           * Used to store the results of searching Maven Central.
           */
          CENTRAL,
          /**
           * Used to store POM files retrieved from central.
           */
          POM
      }
  
      /**
       * Creates the data cache factory.
       *
       * @param settings the configuration settings
       */
      public DataCacheFactory(Settings settings) {
          synchronized (DataCacheFactory.class) {
              if (!initialized) {
                  final File cacheDirectory;
                  try {
                      cacheDirectory = new File(settings.getDataDirectory(), CACHE_DIRECTORY);
                  } catch (IOException ex) {
                      throw new CacheException("Unable to obtain disk cache directory path", ex);
                  }
                  if (!cacheDirectory.isDirectory() && !cacheDirectory.mkdirs()) {
                      throw new CacheException("Unable to create disk cache: " + cacheDirectory);
                  }
                  try (InputStream in = FileUtils.getResourceAsStream(CACHE_PROPERTIES)) {
                      if (in == null) {
                          throw new RuntimeException("Cache properties `" + CACHE_PROPERTIES + "` could not be found");
                     }
 
                     final Properties properties = new Properties();
                     properties.load(in);
                     properties.put("jcs.auxiliary.ODC.attributes.DiskPath", cacheDirectory.getCanonicalPath());
                     for (CacheType t : CacheType.values()) {
                         final File fp = new File(cacheDirectory, t.toString());
                         properties.put("jcs.auxiliary." + t + ".attributes.DiskPath", fp.getCanonicalPath());
                     }
 
                     JCS.setConfigProperties(properties);
                     initialized = true;
                 } catch (IOException ex) {
                     throw new CacheException("Error creating disk cache", ex);
                 }
             }
         }
     }
 
     /**
      * Returns the data cache for Node Audit.
      *
      * @return a references to the data cache for Node Audit
      */
     public DataCache<List<Advisory>> getNodeAuditCache() {
         try {
             final ICompositeCacheAttributes attr = new CompositeCacheAttributes();
             attr.setUseDisk(true);
             attr.setUseLateral(false);
             attr.setUseRemote(false);
             final CacheAccess<String, List<Advisory>> ca = JCS.getInstance("NODEAUDIT", attr);
             final DataCache<List<Advisory>> dc = new DataCache<>(ca);
             return dc;
         } catch (Throwable ex) {
             //some reports of class not found exception, log and disable the cache.
             if (ex instanceof CacheException) {
                 throw ex;
             }
             //TODO we may want to instrument w/ jdiagnostics per #2509
             LOGGER.debug("Error constructing cache for node audit files", ex);
             throw new CacheException(ex);
         }
     }
 
     /**
      * Returns the data cache for POM files.
      *
      * @return a references to the data cache for POM files
      */
     public DataCache<Model> getPomCache() {
         try {
             final ICompositeCacheAttributes attr = new CompositeCacheAttributes();
             attr.setUseDisk(true);
             attr.setUseLateral(false);
             attr.setUseRemote(false);
             final CacheAccess<String, Model> ca = JCS.getInstance("POM", attr);
             final DataCache<Model> dc = new DataCache<>(ca);
             return dc;
         } catch (Throwable ex) {
             //some reports of class not found exception, log and disable the cache.
             if (ex instanceof CacheException) {
                 throw ex;
             }
             //TODO we may want to instrument w/ jdiagnostics per #2509
             LOGGER.debug("Error constructing cache for POM files", ex);
             throw new CacheException(ex);
         }
     }
 
     /**
      * Returns the data cache for Central search.
      *
      * @return a references to the data cache for Central search
      */
     public DataCache<List<MavenArtifact>> getCentralCache() {
         try {
             final ICompositeCacheAttributes attr = new CompositeCacheAttributes();
             attr.setUseDisk(true);
             attr.setUseLateral(false);
             attr.setUseRemote(false);
             final CacheAccess<String, List<MavenArtifact>> ca = JCS.getInstance("CENTRAL", attr);
             final DataCache<List<MavenArtifact>> dc = new DataCache<>(ca);
             return dc;
         } catch (Throwable ex) {
             //some reports of class not found exception, log and disable the cache.
             if (ex instanceof CacheException) {
                 throw ex;
             }
             //TODO we may want to instrument w/ jdiagnostics per #2509
             LOGGER.debug("Error constructing cache for Central files", ex);
             throw new CacheException(ex);
         }
     }
 }