RED-6408, rewrite service from scratch.

src/lib/search-screen-filtering/filter.service.ts

@@ -0,0 +1,66 @@
+import { computed, Injectable, signal } from '@angular/core';
+
+const PARENT_PROPS = ['children', 'indeterminate', 'expanded'] as const;
+const PARENT_FILTER_ID = 'parentFilterId';
+type ParentProps = (typeof PARENT_PROPS)[number];
+type ChildFilter = Omit<Filter, ParentProps> & { [PARENT_FILTER_ID]: string };
+
+interface Filter {
+    id: string;
+    label: string;
+    expanded: boolean;
+    indeterminate: boolean;
+    checked: boolean;
+    disabled: boolean;
+    meta: Record<string, unknown> | undefined;
+    children: Record<string, ChildFilter> | undefined;
+}
+interface FilterGroup {
+    name: string;
+    label: string;
+    filters: Record<string, Filter>;
+}
+
+const safeObj = <T>(obj: T | undefined) => obj ?? ({} as T);
+const getFiltersWithChildren = (filters: Filter[]) => filters.flatMap(filter => [filter, ...Object.values(safeObj(filter.children))]);
+const isChild = (filter: Filter | ChildFilter): filter is ChildFilter => PARENT_FILTER_ID in filter;
+
+@Injectable()
+export class FilterService {
+    readonly #filterGroups = signal<Record<string, FilterGroup> | undefined>(undefined);
+    readonly filterGroups = this.#filterGroups.asReadonly();
+
+    addFilterGroup(newFilterGroup: FilterGroup) {
+        this.#filterGroups.update(filterGroups => ({ ...safeObj(filterGroups), [newFilterGroup.name]: newFilterGroup }));
+    }
+
+    updateFilterGroup(name: string, updates: Partial<Omit<FilterGroup, 'name'>>) {
+        this.#filterGroups.update(filterGroups => {
+            const current = safeObj(filterGroups)[name];
+            if (!current) {
+                console.warn('[Filter service] Cannot update non-existent group: ', name);
+                return filterGroups;
+            }
+            return { ...filterGroups, [name]: { ...current, ...updates } };
+        });
+    }
+
+    removeFilterGroup(name: string) {
+        this.#filterGroups.update(filterGroups => {
+            if (!filterGroups) return undefined;
+            const { [name]: _, ...rest } = filterGroups;
+            return Object.keys(rest) ? rest : undefined;
+        });
+    }
+
+    addFilterToGroup(groupName: string, filter: Filter) {
+        this.#filterGroups.update(filterGroups => {
+            const current = safeObj(filterGroups)[groupName];
+            if (!current) {
+                console.warn('[Filter service] Cannot add filter to non-existent group: ', groupName);
+                return filterGroups;
+            }
+            return { ...filterGroups, [groupName]: { ...current, filters: { ...current.filters, [filter.id]: filter } } };
+        });
+    }
+}