/*
    * 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.external.endpoint;
  
  import static javax.servlet.http.HttpServletResponse.SC_NOT_FOUND;
  import static javax.servlet.http.HttpServletResponse.SC_OK;
  import static javax.servlet.http.HttpServletResponse.SC_UNAUTHORIZED;
  import static org.apache.commons.lang3.StringUtils.trimToNull;
  import static org.opencastproject.index.service.util.JSONUtils.safeString;
  import static org.opencastproject.playlists.PlaylistRestService.SAMPLE_PLAYLIST_JSON;
  import static org.opencastproject.util.DateTimeSupport.toUTC;
  import static org.opencastproject.util.RestUtil.getEndpointUrl;
  import static org.opencastproject.util.doc.rest.RestParameter.Type.INTEGER;
  import static org.opencastproject.util.doc.rest.RestParameter.Type.STRING;
  import static org.opencastproject.util.doc.rest.RestParameter.Type.TEXT;
  
  import org.opencastproject.external.common.ApiMediaType;
  import org.opencastproject.external.common.ApiResponseBuilder;
  import org.opencastproject.playlists.Playlist;
  import org.opencastproject.playlists.PlaylistAccessControlEntry;
  import org.opencastproject.playlists.PlaylistEntry;
  import org.opencastproject.playlists.PlaylistRestService;
  import org.opencastproject.playlists.PlaylistService;
  import org.opencastproject.playlists.serialization.JaxbPlaylist;
  import org.opencastproject.rest.RestConstants;
  import org.opencastproject.security.api.UnauthorizedException;
  import org.opencastproject.systems.OpencastConstants;
  import org.opencastproject.util.NotFoundException;
  import org.opencastproject.util.UrlSupport;
  import org.opencastproject.util.data.Tuple;
  import org.opencastproject.util.doc.rest.RestParameter;
  import org.opencastproject.util.doc.rest.RestQuery;
  import org.opencastproject.util.doc.rest.RestResponse;
  import org.opencastproject.util.doc.rest.RestService;
  import org.opencastproject.util.requests.SortCriterion;
  
  import com.google.gson.JsonArray;
  import com.google.gson.JsonElement;
  import com.google.gson.JsonObject;
  import com.google.gson.JsonPrimitive;
  
  import org.json.simple.parser.ParseException;
  import org.osgi.service.component.ComponentContext;
  import org.osgi.service.component.annotations.Activate;
  import org.osgi.service.component.annotations.Component;
  import org.osgi.service.component.annotations.Reference;
  import org.osgi.service.jaxrs.whiteboard.propertytypes.JaxrsResource;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.IOException;
  import java.net.URI;
  import java.util.List;
  import java.util.Optional;
  
  import javax.servlet.http.HttpServletResponse;
  import javax.ws.rs.DELETE;
  import javax.ws.rs.FormParam;
  import javax.ws.rs.GET;
  import javax.ws.rs.HeaderParam;
  import javax.ws.rs.POST;
  import javax.ws.rs.PUT;
  import javax.ws.rs.Path;
  import javax.ws.rs.PathParam;
  import javax.ws.rs.Produces;
  import javax.ws.rs.QueryParam;
  import javax.ws.rs.core.Response;
  
  @Path("/api/playlists")
  @Produces({ ApiMediaType.JSON, ApiMediaType.VERSION_1_11_0 })
  @RestService(
      name = "externalapiplaylists",
      title = "External API Playlists Service",
      notes = {},
      abstractText = "Provides access to playlist structures"
  )
  @Component(
      immediate = true,
      service = PlaylistsEndpoint.class,
      property = {
          "service.description=External API - Playlists Endpoint",
         "opencast.service.type=org.opencastproject.external.playlists",
         "opencast.service.path=/api/playlists"
     }
 )
 @JaxrsResource
 public class PlaylistsEndpoint {
 
   /** The logging facility */
   private static final Logger logger = LoggerFactory.getLogger(ListProviderEndpoint.class);
 
   /** Base URL of this endpoint */
   protected String endpointBaseUrl;
 
   /** The capture agent service */
   private PlaylistService service;
 
   /** OSGi DI */
   @Reference
   public void setPlaylistService(PlaylistService playlistService) {
     this.service = playlistService;
   }
 
   private PlaylistRestService restService;
 
   @Reference
   public void setPlaylistRestService(PlaylistRestService playlistRestService) {
     this.restService = playlistRestService;
   }
 
   /** OSGi activation method */
   @Activate
   void activate(ComponentContext cc) {
     logger.info("Activating External API - Playlists Endpoint");
 
     final Tuple<String, String> endpointUrl = getEndpointUrl(cc, OpencastConstants.EXTERNAL_API_URL_ORG_PROPERTY,
         RestConstants.SERVICE_PATH_PROPERTY);
     endpointBaseUrl = UrlSupport.concat(endpointUrl.getA(), endpointUrl.getB());
   }
 
   @GET
   @Path("{id}")
   @Produces({ ApiMediaType.JSON, ApiMediaType.VERSION_1_11_0 })
   @RestQuery(
       name = "playlist",
       description = "Get a playlist.",
       returnDescription = "A playlist as JSON",
       pathParameters = {
           @RestParameter(name = "id", isRequired = true, description = "The playlist identifier", type = STRING),
       },
       responses = {
           @RestResponse(description = "Returns the playlist.", responseCode = HttpServletResponse.SC_OK),
           @RestResponse(description = "The specified playlist instance does not exist.",
               responseCode = HttpServletResponse.SC_NOT_FOUND),
           @RestResponse(description = "The user doesn't have the rights to make this request.",
               responseCode = HttpServletResponse.SC_FORBIDDEN),
           @RestResponse(description = "The request is invalid or inconsistent.",
               responseCode = HttpServletResponse.SC_BAD_REQUEST),
       })
   public Response getPlaylistAsJson(
       @HeaderParam("Accept") String acceptHeader,
       @PathParam("id") String id) {
     try {
       Playlist playlist = service.getPlaylistById(id);
 
       return ApiResponseBuilder.Json.ok(acceptHeader, playlistToJson(playlist));
     } catch (NotFoundException e) {
       return ApiResponseBuilder.notFound("Cannot find playlist instance with id '%s'.", id);
     } catch (UnauthorizedException e) {
       return Response.status(Response.Status.FORBIDDEN).build();
     } catch (IllegalStateException e) {
       return Response.status(Response.Status.BAD_REQUEST).build();
     }
   }
 
   @GET
   @Produces({ ApiMediaType.JSON, ApiMediaType.VERSION_1_11_0 })
   @Path("")
   @RestQuery(
       name = "playlists",
       description = "Get playlists. Playlists that you do not have read access to will not show up.",
       returnDescription = "A JSON object containing an array.",
       restParameters = {
           @RestParameter(name = "limit", isRequired = false, type = INTEGER,
               description = "The maximum number of results to return for a single request.", defaultValue = "100"),
           @RestParameter(name = "offset", isRequired = false, type = INTEGER,
               description = "The index of the first result to return."),
           @RestParameter(name = "sort", isRequired = false, type = STRING,
               description = "Sort the results based upon a sorting criteria. A criteria is specified as a pair such as:"
                   + "<Sort Name>:ASC or <Sort Name>:DESC. Adding the suffix ASC or DESC sets the order as ascending or"
                   + "descending order and is mandatory. Sort Name is case sensitive. Supported Sort Names are 'updated'"
               , defaultValue = "updated:ASC"),
       },
       responses = {
           @RestResponse(description = "Returns the playlist.", responseCode = HttpServletResponse.SC_OK),
           @RestResponse(description = "The request is invalid or inconsistent.",
               responseCode = HttpServletResponse.SC_BAD_REQUEST),
       })
   public Response getPlaylistsAsJson(
       @HeaderParam("Accept") String acceptHeader,
       @QueryParam("limit") int limit,
       @QueryParam("offset") int offset,
       @QueryParam("sort") String sort) {
     if (offset < 0) {
       return Response.status(Response.Status.BAD_REQUEST).build();
     }
 
     if (limit < 0) {
       return Response.status(Response.Status.BAD_REQUEST).build();
     }
 
     SortCriterion sortCriterion = new SortCriterion("", SortCriterion.Order.None);
     Optional<String> optSort = Optional.ofNullable(trimToNull(sort));
     if (optSort.isPresent()) {
       sortCriterion = SortCriterion.parse(optSort.get());
 
       switch (sortCriterion.getFieldName()) {
         case "updated":
           break;
         default:
           logger.info("Unknown sort criteria {}", sortCriterion.getFieldName());
           return Response.serverError().status(Response.Status.BAD_REQUEST).build();
       }
     }
 
     List<Playlist> playlists = service.getPlaylists(limit, offset, sortCriterion);
 
     JsonArray playlistsJson = new JsonArray();
     for (Playlist p : playlists) {
       playlistsJson.add(playlistToJson(p));
     }
 
     return Response.ok(playlistsJson.toString(), acceptHeader).build();
   }
 
   @POST
   @Produces({ ApiMediaType.JSON, ApiMediaType.VERSION_1_11_0 })
   @Path("")
   @RestQuery(
       name = "create",
       description = "Creates a playlist.",
       returnDescription = "The created playlist.",
       restParameters = {
           @RestParameter(name = "playlist", isRequired = false, description = "Playlist in JSON format", type = TEXT,
               jaxbClass = JaxbPlaylist.class, defaultValue = SAMPLE_PLAYLIST_JSON)
       },
       responses = {
           @RestResponse(description = "Playlist created.", responseCode = HttpServletResponse.SC_CREATED),
           @RestResponse(description = "The user doesn't have the rights to make this request.",
               responseCode = HttpServletResponse.SC_FORBIDDEN),
           @RestResponse(description = "The request is invalid or inconsistent.",
               responseCode = HttpServletResponse.SC_BAD_REQUEST),
       })
   public Response createAsJson(
       @HeaderParam("Accept") String acceptHeader,
       @FormParam("playlist") String playlistText) {
     try {
       // Map JSON to JPA
       Playlist playlist = restService.parseJsonToPlaylist(playlistText);
 
       // Persist
       playlist = service.update(playlist);
       return ApiResponseBuilder.Json.created(
           acceptHeader,
           URI.create(getPlaylistUrl(playlist.getId())),
           playlistToJson(playlist)
       );
     } catch (UnauthorizedException e) {
       return Response.status(Response.Status.FORBIDDEN).build();
     } catch (ParseException | IOException | IllegalArgumentException e) {
       return Response.status(Response.Status.BAD_REQUEST).build();
     }
   }
 
   @PUT
   @Produces({ ApiMediaType.JSON, ApiMediaType.VERSION_1_11_0 })
   @Path("{id}")
   @RestQuery(
       name = "update",
       description = "Updates a playlist.",
       returnDescription = "The updated playlist.",
       pathParameters = {
           @RestParameter(name = "id", isRequired = true, description = "Playlist identifier", type = STRING)
       },
       restParameters = {
           @RestParameter(name = "playlist", isRequired = false, description = "Playlist in JSON format", type = TEXT,
               jaxbClass = JaxbPlaylist.class, defaultValue = SAMPLE_PLAYLIST_JSON)
       },
       responses = {
           @RestResponse(description = "Playlist updated.", responseCode = HttpServletResponse.SC_OK),
           @RestResponse(description = "The user doesn't have the rights to make this request.",
               responseCode = HttpServletResponse.SC_FORBIDDEN),
           @RestResponse(description = "The request is invalid or inconsistent.",
               responseCode = HttpServletResponse.SC_BAD_REQUEST),
       })
   public Response updateAsJson(
       @HeaderParam("Accept") String acceptHeader,
       @PathParam("id") String id,
       @FormParam("playlist") String playlistText) {
     try {
       Playlist playlist = service.updateWithJson(id, playlistText);
       return ApiResponseBuilder.Json.ok(acceptHeader, playlistToJson(playlist));
     } catch (UnauthorizedException e) {
       return Response.status(Response.Status.FORBIDDEN).build();
     } catch (IOException | IllegalArgumentException e) {
       return Response.status(Response.Status.BAD_REQUEST).build();
     }
   }
 
   @DELETE
   @Produces({ ApiMediaType.JSON, ApiMediaType.VERSION_1_11_0 })
   @Path("{id}")
   @RestQuery(
       name = "remove",
       description = "Removes a playlist.",
       returnDescription = "The removed playlist.",
       pathParameters = {
           @RestParameter(name = "id", isRequired = true, description = "Playlist identifier", type = STRING)
       },
       responses = {
           @RestResponse(responseCode = SC_OK, description = "Playlist removed."),
           @RestResponse(responseCode = SC_NOT_FOUND, description = "No playlist with that identifier exists."),
           @RestResponse(responseCode = SC_UNAUTHORIZED, description = "Not authorized to perform this action")
       })
   public Response remove(
       @HeaderParam("Accept") String acceptHeader,
       @PathParam("id") String id) {
     try {
       Playlist playlist = service.remove(id);
 
       return ApiResponseBuilder.Json.ok(acceptHeader, playlistToJson(playlist));
     } catch (NotFoundException e) {
       return ApiResponseBuilder.notFound("Cannot find playlist instance with id '%s'.", id);
     } catch (UnauthorizedException e) {
       return Response.status(Response.Status.FORBIDDEN).build();
     }
   }
 
   private JsonObject playlistToJson(Playlist playlist) {
     JsonObject json = new JsonObject();
 
     json.addProperty("id", playlist.getId());
     JsonArray entriesArray = new JsonArray();
     for (PlaylistEntry entry : playlist.getEntries()) {
       entriesArray.add(playlistEntryToJson(entry));
     }
     json.add("entries", entriesArray);
     json.addProperty("title", safeString(playlist.getTitle()));
     json.addProperty("description", safeString(playlist.getDescription()));
     json.addProperty("creator", safeString(playlist.getCreator()));
     json.addProperty("updated", playlist.getUpdated() != null ? toUTC(playlist.getUpdated().getTime()) : "");
     JsonArray aceArray = new JsonArray();
     for (PlaylistAccessControlEntry ace : playlist.getAccessControlEntries()) {
       aceArray.add(playlistAccessControlEntryToJson(ace));
     }
     json.add("accessControlEntries", aceArray);
 
     return json;
   }
 
   private JsonObject playlistEntryToJson(PlaylistEntry playlistEntry) {
     JsonObject json = new JsonObject();
 
     json.addProperty("id", playlistEntry.getId());
     if (playlistEntry.getContentId() != null) {
       json.addProperty("contentId", playlistEntry.getContentId());
     } else {
       json.add("contentId", null);
     }
 
     json.add("type", enumToJSON(playlistEntry.getType()));
 
     return json;
   }
 
   private JsonObject playlistAccessControlEntryToJson(PlaylistAccessControlEntry playlistAccessControlEntry) {
     JsonObject json = new JsonObject();
 
     json.addProperty("id", playlistAccessControlEntry.getId());
     json.addProperty("allow", playlistAccessControlEntry.isAllow());
     json.addProperty("role", playlistAccessControlEntry.getRole());
     json.addProperty("action", playlistAccessControlEntry.getAction());
 
     return json;
   }
 
   private JsonElement enumToJSON(Enum<?> e) {
     return e == null ? null : new JsonPrimitive(e.toString());
   }
 
   private String getPlaylistUrl(String playlistId) {
     return UrlSupport.concat(endpointBaseUrl, playlistId);
   }
 }