/*
    * 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.message.broker.api.scheduler;
  
  import org.opencastproject.metadata.dublincore.DublinCoreCatalog;
  import org.opencastproject.metadata.dublincore.DublinCoreXmlFormat;
  import org.opencastproject.security.api.AccessControlList;
  import org.opencastproject.security.api.AccessControlParser;
  
  import com.google.gson.Gson;
  
  import org.apache.commons.lang3.StringUtils;
  
  import java.io.IOException;
  import java.io.Serializable;
  import java.io.StringReader;
  import java.util.Date;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Properties;
  import java.util.Set;
  
  /**
   * {@link Serializable} class that represents all of the possible messages sent through a SchedulerService queue.
   */
  public class SchedulerItem implements Serializable {
    private static final long serialVersionUID = 6061069989788904237L;
  
    private static final Gson gson = new Gson();
  
    private final String event;
    private final String properties;
    private final String acl;
    private final String agentId;
    private final long end;
    private final String presenters;
    private final String recordingState;
    private final long start;
  
    private final Type type;
  
    public enum Type {
      UpdateCatalog, UpdateProperties, UpdateAcl, UpdateAgentId, UpdateEnd, UpdatePresenters, UpdateRecordingStatus,
      UpdateStart, DeleteRecordingStatus, Delete
    };
  
    /**
     * @param event
     *          The event details to update to.
     * @return Builds {@link SchedulerItem} for updating a scheduled event.
     */
    public static SchedulerItem updateCatalog(DublinCoreCatalog event) {
      return new SchedulerItem(event);
    }
  
    /**
     * @param properties
     *          The new properties to update to.
     * @return Builds {@link SchedulerItem} for updating the properties of an event.
     */
    public static SchedulerItem updateProperties(Map<String, String> properties) {
      return new SchedulerItem(properties);
    }
  
    /**
     * @return Builds {@link SchedulerItem} for deleting an event.
     */
    public static SchedulerItem delete() {
      return new SchedulerItem(Type.Delete);
    }
  
    /**
     * @param accessControlList
     *          the access control list
     * @return Builds {@link SchedulerItem} for updating the access control list of an event.
     */
    public static SchedulerItem updateAcl(AccessControlList accessControlList) {
      return new SchedulerItem(accessControlList);
    }
  
   /**
    * @param state
    *          The recording state
    * @param lastHeardFrom
    *          The recording last heard from date
    * @return Builds {@link SchedulerItem} for updating a recording.
    */
   public static SchedulerItem updateRecordingStatus(String state, Long lastHeardFrom) {
     return new SchedulerItem(state, lastHeardFrom);
   }
 
   /**
    * @param start
    *        The new start time for the event.
    * @return Builds {@link SchedulerItem} for updating the start of an event.
    */
   public static SchedulerItem updateStart(Date start) {
     return new SchedulerItem(start, null, Type.UpdateStart);
   }
 
   /**
    * @param end
    *        The new end time for the event.
    * @return Builds {@link SchedulerItem} for updating the end of an event.
    */
   public static SchedulerItem updateEnd(Date end) {
     return new SchedulerItem(null, end, Type.UpdateEnd);
   }
 
   /**
    * @param presenters
    *        The new set of presenters for the event.
    * @return Builds {@link SchedulerItem} for updating the presenters of an event.
    */
   public static SchedulerItem updatePresenters(Set<String> presenters) {
     return new SchedulerItem(presenters);
   }
 
   /**
    * @param agentId
    *        The new agent id for the event.
    * @return Builds {@link SchedulerItem} for updating the agent id of an event.
    */
   public static SchedulerItem updateAgent(String agentId) {
     return new SchedulerItem(agentId);
   }
 
   /**
    * @return Builds {@link SchedulerItem} for deleting a recording.
    */
   public static SchedulerItem deleteRecordingState() {
     return new SchedulerItem(Type.DeleteRecordingStatus);
   }
 
   /**
    * Constructor to build an update event {@link SchedulerItem}.
    *
    * @param event
    *          The event details to update.
    */
   public SchedulerItem(DublinCoreCatalog event) {
     try {
       this.event = event.toXmlString();
     } catch (IOException e) {
       throw new IllegalStateException();
     }
     this.properties = null;
     this.acl = null;
     this.agentId = null;
     this.end = -1;
     this.presenters = null;
     this.recordingState = null;
     this.start = -1;
     this.type = Type.UpdateCatalog;
   }
 
   /**
    * Constructor to build an update properties for an event {@link SchedulerItem}.
    *
    * @param properties
    *          The properties to update.
    */
   public SchedulerItem(Map<String, String> properties) {
     this.event = null;
     this.properties = serializeProperties(properties);
     this.acl = null;
     this.agentId = null;
     this.end = -1;
     this.presenters = null;
     this.recordingState = null;
     this.start = -1;
     this.type = Type.UpdateProperties;
   }
 
   /**
    * Constructor to build a delete event {@link SchedulerItem}.
    *
    */
   public SchedulerItem(Type type) {
     this.event = null;
     this.properties = null;
     this.acl = null;
     this.agentId = null;
     this.end = -1;
     this.presenters = null;
     this.recordingState = null;
     this.start = -1;
     this.type = type;
   }
 
   /**
    * Constructor to build an update access control list event {@link SchedulerItem}.
    *
    * @param accessControlList
    *          The access control list
    */
   public SchedulerItem(AccessControlList accessControlList) {
     this.event = null;
     this.properties = null;
     try {
       this.acl = AccessControlParser.toJson(accessControlList);
     } catch (IOException e) {
       throw new IllegalStateException();
     }
     this.agentId = null;
     this.end = -1;
     this.presenters = null;
     this.recordingState = null;
     this.start = -1;
     this.type = Type.UpdateAcl;
   }
 
   /**
    * Constructor to build an update recording status event {@link SchedulerItem}.
    *
    * @param state
    *          the recording status
    * @param lastHeardFrom
    *          the last heard from time
    */
   public SchedulerItem(String state, Long lastHeardFrom) {
     this.event = null;
     this.properties = null;
     this.acl = null;
     this.agentId = null;
     this.end = -1;
     this.presenters = null;
     this.recordingState = state;
     this.start = -1;
     this.type = Type.UpdateRecordingStatus;
   }
 
   public SchedulerItem(Date start, Date end, Type type) {
     this.event = null;
     this.acl = null;
     this.agentId = null;
     this.end = end == null ? -1 : end.getTime();
     this.presenters = null;
     this.properties = null;
     this.recordingState = null;
     this.start = start == null ? -1 : start.getTime();
     this.type = type;
   }
 
   public SchedulerItem(String agentId) {
     this.event = null;
     this.acl = null;
     this.agentId = agentId;
     this.end = -1;
     this.presenters = null;
     this.properties = null;
     this.recordingState = null;
     this.start = -1;
     this.type = Type.UpdateAgentId;
   }
 
   public SchedulerItem(Set<String> presenters) {
     this.event = null;
     this.acl = null;
     this.agentId = null;
     this.end = -1;
     this.presenters = gson.toJson(presenters);
     this.properties = null;
     this.recordingState = null;
     this.start = -1;
     this.type = Type.UpdatePresenters;
   }
   public DublinCoreCatalog getEvent() {
     if (StringUtils.isBlank(event)) {
       return null;
     }
 
     return DublinCoreXmlFormat.readOpt(event).orNull();
   }
 
   public Map<String, String> getProperties() {
     try {
       return parseProperties(properties);
     } catch (IOException e) {
       throw new IllegalStateException();
     }
   }
 
   public AccessControlList getAcl() {
     try {
       return acl == null ? null : AccessControlParser.parseAcl(acl);
     } catch (Exception e) {
       throw new IllegalStateException(e);
     }
   }
 
   public String getAgentId() {
     return agentId;
   }
 
   public Date getEnd() {
     return end < 0 ? null : new Date(end);
   }
 
   @SuppressWarnings("unchecked")
   public Set<String> getPresenters() {
     return gson.fromJson(presenters, Set.class);
   }
 
   public String getRecordingState() {
     return recordingState;
   }
 
   public Date getStart() {
     return start < 0 ? null : new Date(start);
   }
 
   public Type getType() {
     return type;
   }
 
   /**
    * Serializes Properties to String.
    *
    * @param caProperties
    *          properties to be serialized
    * @return serialized properties
    */
   private String serializeProperties(Map<String, String> caProperties) {
     StringBuilder wfPropertiesString = new StringBuilder();
     for (Map.Entry<String, String> entry : caProperties.entrySet()) {
       wfPropertiesString.append(entry.getKey() + "=" + entry.getValue() + "\n");
     }
     return wfPropertiesString.toString();
   }
 
   /**
    * Parses Properties represented as String.
    *
    * @param serializedProperties
    *          properties to be parsed.
    * @return parsed properties
    * @throws IOException
    *           if parsing fails
    */
   private Map<String, String> parseProperties(String serializedProperties) throws IOException {
     Properties caProperties = new Properties();
     caProperties.load(new StringReader(serializedProperties));
     return new HashMap<String, String>((Map) caProperties);
   }
 
 }