/*
    * 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 org.opencastproject.external.common.ApiMediaType;
  import org.opencastproject.external.common.ApiResponseBuilder;
  import org.opencastproject.list.api.DefaultResourceListQuery;
  import org.opencastproject.list.api.ListProviderException;
  import org.opencastproject.list.api.ListProviderNotFoundException;
  import org.opencastproject.list.api.ListProvidersService;
  import org.opencastproject.list.query.StringListFilter;
  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 com.google.gson.Gson;
  
  import org.json.simple.JSONArray;
  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.util.Map;
  
  import javax.servlet.http.HttpServletResponse;
  import javax.ws.rs.GET;
  import javax.ws.rs.HeaderParam;
  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/listproviders")
  @Produces({ ApiMediaType.JSON, ApiMediaType.VERSION_1_10_0, ApiMediaType.VERSION_1_11_0 })
  @RestService(
          name = "externalapilistproviders",
          title = "External API List Providers Service",
          notes = {},
          abstractText = "Provides resources and operations related to configurable lists"
  )
  @Component(
          immediate = true,
          service = ListProviderEndpoint.class,
          property = {
                  "service.description=External API - List Providers Endpoint",
                  "opencast.service.type=org.opencastproject.external.listproviders",
                  "opencast.service.path=/api/listproviders"
          }
  )
  @JaxrsResource
  public class ListProviderEndpoint {
  
    /** The logging facility */
    private static final Logger logger = LoggerFactory.getLogger(ListProviderEndpoint.class);
  
    /** The capture agent service */
    private ListProvidersService listProvidersService;
  
    /** OSGi DI */
    @Reference
    public void setListProvidersService(ListProvidersService listProvidersService) {
      this.listProvidersService = listProvidersService;
    }
  
    /** OSGi activation method */
    @Activate
    void activate(ComponentContext cc) {
      logger.info("Activating External API - List Providers Endpoint");
    }
  
    @GET
    @Path("providers.json")
    @RestQuery(
        name = "availableProviders",
        description = "Provides the list of the available list providers",
       responses = {
           @RestResponse(description = "Returns the availables list providers.",
               responseCode = HttpServletResponse.SC_OK)
       },
       returnDescription = "")
   public Response getAvailableProviders(@HeaderParam("Accept") String acceptHeader) {
     JSONArray list = new JSONArray();
 
     list.add(listProvidersService.getAvailableProviders());
 
     return ApiResponseBuilder.Json.ok(acceptHeader, list.toJSONString());
   }
 
   @GET
   @Path("{source}.json")
   @RestQuery(
       name = "list",
       description = "Provides key-value list from the given source",
       pathParameters = {
           @RestParameter(name = "source", description = "The source for the key-value list", isRequired = true,
               type = RestParameter.Type.STRING)
       },
       restParameters = {
           @RestParameter(description = "The maximum number of items to return per page", isRequired = false,
               name = "limit", type = RestParameter.Type.INTEGER),
           @RestParameter(description = "The offset", isRequired = false, name = "offset",
               type = RestParameter.Type.INTEGER),
           @RestParameter(description = "Filters", isRequired = false, name = "filter",
               type = RestParameter.Type.STRING)
       },
       responses = {
           @RestResponse(description = "Returns the key-value list for the given source.",
               responseCode = HttpServletResponse.SC_OK)
       },
       returnDescription = "")
   public Response getList(@PathParam("source") final String source, @QueryParam("limit") final int limit,
           @QueryParam("filter") final String filter, @QueryParam("offset") final int offset,
           @HeaderParam("Accept") String acceptHeader) {
 
     DefaultResourceListQuery query = new DefaultResourceListQuery();
     query.setLimit(limit);
     query.setOffset(offset);
     addRequestFiltersToQuery(filter, query);
     Map<String, String> autocompleteList;
     try {
       autocompleteList = listProvidersService.getList(source, query, false);
     } catch (ListProviderNotFoundException e) {
       logger.debug("No list found for {}", source, e);
       return ApiResponseBuilder.notFound("");
     } catch (ListProviderException e) {
       logger.error("Server error when getting list from provider {}", source, e);
       return ApiResponseBuilder.serverError("");
     }
 
     Gson gson = new Gson();
     String jsonList = gson.toJson(autocompleteList);
     return ApiResponseBuilder.Json.ok(acceptHeader, jsonList);
   }
 
   /**
    * Add the string based filters to the given list query.
    *
    * @param filterString
    *          The string based filters
    * @param query
    *          The query to update with the filters
    */
   private void addRequestFiltersToQuery(final String filterString, DefaultResourceListQuery query) {
     if (filterString != null) {
       String[] filters = filterString.split(",");
       for (String filter : filters) {
         String[] splitFilter = filter.split(":", 2);
         if (splitFilter != null && splitFilter.length == 2) {
           String key = splitFilter[0].trim();
           String value = splitFilter[1].trim();
           query.addFilter(new StringListFilter(key, value));
         }
       }
     }
   }
 
 }