UX: more work on a search function

src/Logic/Geocoding/CombinedSearcher.ts

@@ -9,13 +9,35 @@ export default class CombinedSearcher implements GeocodingProvider {
         this._providersWithSuggest = providers.filter(pr => pr.suggest !== undefined)
     }
 
+    /**
+     * Merges the geocode-results from various sources.
+     * If the same osm-id is mentioned multiple times, only the first result will be kept
+     * @param geocoded
+     * @private
+     */
+    private merge(geocoded: GeoCodeResult[][]): GeoCodeResult[]{
+        const results : GeoCodeResult[] = []
+        const seenIds = new Set<string>()
+        for (const geocodedElement of geocoded) {
+            for (const entry of geocodedElement) {
+                const id = entry.osm_type+ entry.osm_id
+                if(seenIds.has(id)){
+                    continue
+                }
+                seenIds.add(id)
+                results.push(entry)
+            }
+        }
+        return results
+    }
+
     async search(query: string, options?: GeocodingOptions): Promise<GeoCodeResult[]> {
         const results = await Promise.all(this._providers.map(pr => pr.search(query, options)))
-        return results.flatMap(x => x)
+        return this.merge(results)
     }
 
     async suggest(query: string, options?: GeocodingOptions): Promise<GeoCodeResult[]> {
         const results = await Promise.all(this._providersWithSuggest.map(pr => pr.suggest(query, options)))
-        return results.flatMap(x => x)
+        return this.merge(results)
     }
 }