Add land use classification API processing logic

app/src/api/services/building.ts

@@ -92,12 +92,16 @@ async function queryBuildingsByReference(key: string, ref: string) {
     }
 }
 
-async function getBuildingById(id: number) {
-    try {
-        const building = await db.one(
+async function getCurrentBuildingDataById(id: number) {
+    return db.one(
             'SELECT * FROM buildings WHERE building_id = $1',
             [id]
         );
+}
+
+async function getBuildingById(id: number) {
+    try {
+        const building = await getCurrentBuildingDataById(id);
 
         building.edit_history = await getBuildingEditHistory(id);
 
@@ -422,6 +426,7 @@ function compare(oldObj: object, newObj: object): [object, object] {
 export {
     queryBuildingsAtPoint,
     queryBuildingsByReference,
+    getCurrentBuildingDataById,
     getBuildingById,
     getBuildingLikeById,
     getBuildingEditHistory,

app/src/api/services/domainLogic/currentLandUseClassifications.ts

@@ -0,0 +1,75 @@
+import db from '../../../db';
+import { getBuildingById, getCurrentBuildingDataById } from '../building';
+
+export async function processCurrentLandUseClassifications(building: any): Promise<any> {
+
+    const updateFrom = getUpdateStartingStage(building);
+    const currentData = await getCurrentBuildingDataById(building.building_id);
+
+    if(updateFrom === 'class') {
+        building.current_landuse_group = await deriveGroupFromClass(building.current_landuse_class);
+        building.current_landuse_order = await deriveOrderFromGroup(building.current_landuse_group);
+    } else if (updateFrom === 'group') {
+        if(currentData.current_landuse_class == undefined) {
+            building.current_landuse_order = await deriveOrderFromGroup(building.current_landuse_group);
+        } else {
+            delete building.current_landuse_group;
+            delete building.current_landuse_order;
+        }
+    } else if (updateFrom === 'order') {
+        if(currentData.current_landuse_class == undefined && currentData.current_landuse_group == undefined) {
+            // do nothing, building.current_landuse_order is already correctly set and can be used for the update
+        } else {
+            delete building.current_landuse_order;
+        }
+    }
+
+    return building;
+}
+
+/**
+ * Choose which level of the land use classification hierarchy the update should start from.
+ * @param building 
+ */
+function getUpdateStartingStage(building) {
+    if(building.hasOwnProperty('current_landuse_class')) {
+        return 'class';
+    } else if(building.hasOwnProperty('current_landuse_group')) {
+        return 'group';
+    } else if(building.hasOwnProperty('current_landuse_order')) {
+        return 'order';
+    } else return 'none';
+}
+
+function deriveGroupFromClass(classes: string[]): Promise<string[]> {
+    return db.many(
+        `
+        SELECT DISTINCT parent.description
+        FROM reference_tables.buildings_landuse_group AS parent
+        JOIN reference_tables.buildings_landuse_class AS child
+        ON child.parent_group_id = parent.landuse_id
+        WHERE child.description IN ($1:csv)
+        ORDER BY parent.description`,
+        [classes]
+    );
+}
+
+async function deriveOrderFromGroup(groups: string[]): Promise<string> {
+    const orders = await db.many(
+        `
+        SELECT DISTINCT parent.description
+        FROM reference_tables.buildings_landuse_order AS parent
+        JOIN reference_tables.buildings_landuse_group AS child
+        ON child.parent_order_id = parent.landuse_id
+        WHERE child.description IN ($1:csv)
+        ORDER BY parent.description
+        `,
+        [groups]
+    );
+
+    if(orders.length === 1) {
+        return orders[0];
+    } else if (orders.length > 1) {
+        return 'Mixed use';
+    } else return null;
+}