language search slightly more efficient; fix ordering of results

lib/controllers/v1/computervision_controller.js

@@ -619,6 +619,10 @@ const ComputervisionController = class ComputervisionController {
   }
 
   static async languageSearch( req ) {
+    if ( !req.userSession || !req.userSession.isAdmin ) {
+      throw util.httpError( 401, "Unauthorized" );
+    }
+
     if ( _.isEmpty( req.query.q ) ) {
       throw util.httpError( 422, "Missing required parameter `q`" );
     }
@@ -656,21 +660,22 @@ const ComputervisionController = class ComputervisionController {
     const photos = _.keyBy( json.results, "photo_id" );
     const photosQuery = squel
       .select( )
-      .field( "p.id photo_id, MAX(o.id) observation_id" )
-      .from( "photos p" )
-      .join( "observation_photos op", null, "p.id = op.photo_id" )
-      .join( "observations o", null, "op.observation_id = o.id" )
-      .where( "p.id IN ?", _.keys( photos ) )
-      .group( "p.id" );
+      .field( "op.photo_id, op.observation_id" )
+      .from( "observation_photos op" )
+      .where( "op.photo_id IN ?", _.keys( photos ) );
     const { rows } = await pgClient.replica.query( photosQuery.toString( ) );
-    const results = [];
-    _.each( rows, row => {
-      results.push( {
+    const resultsObject = { };
+    _.each( _.reverse( _.sortBy( rows, "observation_id" ) ), row => {
+      if ( _.has( resultsObject, row.photo_id ) ) {
+        return;
+      }
+      resultsObject[row.photo_id] = {
         observation_id: row.observation_id,
         photo_id: row.photo_id,
         score: photos[row.photo_id]
-      } );
+      };
     } );
+    const results = _.values( resultsObject );
     const localeOpts = util.localeOpts( req );
     await Observation.preloadInto( req, results, localeOpts );
     _.each( results, r => {
@@ -681,7 +686,7 @@ const ComputervisionController = class ComputervisionController {
       total_results: _.size( results ),
       page: Number( req.query.page ) || 1,
       per_page: _.size( results ),
-      results
+      results: _.reverse( _.sortBy( results, "score" ) )
     };
     return response;
   }