/*
    * Licensed to The Apereo Foundation under one or more contributor license
    * agreements. See the NOTICE file distributed with this work for additional
    * information regarding copyright ownership.
    *
    *
    * The Apereo Foundation licenses this file to you under the Educational
    * Community 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://opensource.org/licenses/ecl2.txt
   *
   * 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.
   *
   */
  package org.opencastproject.assetmanager.util;
  
  import static com.entwinemedia.fn.Stream.$;
  import static org.opencastproject.assetmanager.api.fn.Enrichments.enrich;
  
  import org.opencastproject.assetmanager.api.AssetManager;
  import org.opencastproject.assetmanager.api.Snapshot;
  import org.opencastproject.assetmanager.api.query.AQueryBuilder;
  import org.opencastproject.mediapackage.MediaPackage;
  import org.opencastproject.security.api.UnauthorizedException;
  import org.opencastproject.workflow.api.ConfiguredWorkflow;
  import org.opencastproject.workflow.api.WorkflowDatabaseException;
  import org.opencastproject.workflow.api.WorkflowInstance;
  import org.opencastproject.workflow.api.WorkflowParsingException;
  import org.opencastproject.workflow.api.WorkflowService;
  
  import com.entwinemedia.fn.Fn;
  import com.entwinemedia.fn.Stream;
  import com.entwinemedia.fn.data.Opt;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Utility class to apply workflows to episodes. Removed 'final class' so that we can mock it for
   * unit tests.
   */
  public class Workflows {
    /** Log facility */
    private static final Logger logger = LoggerFactory.getLogger(Workflows.class);
  
    private final AssetManager am;
    private final WorkflowService wfs;
  
    public Workflows(AssetManager am, WorkflowService wfs) {
      this.am = am;
      this.wfs = wfs;
    }
  
    /**
     * Apply a workflow to the latest version of each media package.
     */
    public Stream<WorkflowInstance> applyWorkflowToLatestVersion(Iterable<String> mpIds, ConfiguredWorkflow wf) {
      return $(mpIds).bind(findLatest).map(getMediapackage).bind(applyWorkflow(wf));
    }
  
    /**
     * Apply a workflow to a media package. The function returns some workflow instance if the
     * workflow could be started successfully, none otherwise.
     */
    public Fn<MediaPackage, Opt<WorkflowInstance>> applyWorkflow(final ConfiguredWorkflow wf) {
      return new Fn<MediaPackage, Opt<WorkflowInstance>>() {
        @Override public Opt<WorkflowInstance> apply(MediaPackage mp) {
          try {
            return Opt.some(wfs.start(wf.getWorkflowDefinition(), mp, wf.getParameters()));
          } catch (WorkflowDatabaseException | WorkflowParsingException | UnauthorizedException e) {
            logger.error("Cannot start workflow on media package " + mp.getIdentifier().toString(), e);
            return Opt.none();
          }
        }
      };
    }
  
    // CHECKSTYLE:OFF
    private final Fn<Snapshot, MediaPackage> getMediapackage = new Fn<Snapshot, MediaPackage>() {
      @Override public MediaPackage apply(Snapshot snapshot) {
        return snapshot.getMediaPackage();
      }
    };
    // CHECKSTYLE:ON
  
    private final Fn<String, Iterable<Snapshot>> findLatest = new Fn<String, Iterable<Snapshot>>() {
      @Override public Iterable<Snapshot> apply(String mpId) {
        AQueryBuilder q = am.createQuery();
        return enrich(q.select(q.snapshot()).where(q.mediaPackageId(mpId).and(q.version().isLatest())).run())
            .getSnapshots();
      }
    };
  }