SELV3-780: automatically findd the lowest geo level (#50)

src/admin-geographic-zone-population/admin-geographic-zone-population.service.js

@@ -23,17 +23,22 @@
 
     geoZoneCatchmentPopulationService.$inject = [
         'featureFlagService',
-        'GeographicLevelService',
+        'GeoLevelResource',
         'CATCHMENT_POPULATION_CALC_AUTO_FEATURE_FLAG'
     ];
 
     function geoZoneCatchmentPopulationService(
         featureFlagService,
-        GeographicLevelService,
+        GeoLevelResource,
         CATCHMENT_POPULATION_CALC_AUTO_FEATURE_FLAG
     ) {
         const isCatchmentPopulationAutoCalc = featureFlagService.get(CATCHMENT_POPULATION_CALC_AUTO_FEATURE_FLAG);
-        const lowestLevel = GeographicLevelService.getTheLowestLevelNumber();
+        let lowestLevel = null;
+
+        new GeoLevelResource().getTheLowestGeoLevel()
+            .then(function(geoLevel) {
+                lowestLevel = geoLevel.levelNumber;
+            });
 
         return {
             isEditable: function(geographicZone) {

src/referencedata-geographic-level/geo-level-resource.js

@@ -33,6 +33,24 @@
             });
         }
 
+        GeoLevelResource.prototype.getTheLowestGeoLevel = getTheLowestGeoLevel;
+
         return GeoLevelResource;
+
+        function getTheLowestGeoLevel() {
+            return new Promise(function(resolve) {
+                new GeoLevelResource().query()
+                    .then(function(resource) {
+                        const lowestGeoLevel = resource.content.reduce(function(lowestGeoLevel, geoLevel) {
+                            // Compare and keep the one with the highest `levelNumber` value
+                            return geoLevel.levelNumber > lowestGeoLevel.levelNumber
+                                ? geoLevel : lowestGeoLevel;
+                        });
+
+                        resolve(lowestGeoLevel);
+                    });
+            });
+        }
+
     }
 })();