CAtegory component making

src/app/facades/platform/category.facade.ts

@@ -0,0 +1,90 @@
+import { Injectable, inject, signal } from '@angular/core';
+import { BehaviorSubject, Observable, map, of, shareReplay, switchMap } from 'rxjs';
+import { CategoryService } from '../../core/categories/category.service';
+import { Category } from '../../core/categories/models/category-domain.model';
+
+@Injectable({ providedIn: 'root' })
+export class CategoryFacade {
+  private readonly categoryService = inject(CategoryService);
+  private readonly selectedCategoryId = new BehaviorSubject<number | null>(null);
+
+  readonly allCategories = signal<Category[]>([]);
+  readonly categoryTree = signal<Category[]>([]);
+  readonly rootCategories = signal<Category[]>([]);
+  readonly selectedCategory = signal<Category | null>(null);
+  readonly breadcrumb = signal<Category[]>([]);
+  readonly children = signal<Category[]>([]);
+  readonly loading = signal(false);
+  readonly error = signal<string | null>(null);
+
+  readonly allCategories$ = this.categoryService.getAllCategories()
+    .pipe(shareReplay({ bufferSize: 1, refCount: true }));
+  readonly categoryTree$ = this.categoryService.getCategoryTree()
+    .pipe(shareReplay({ bufferSize: 1, refCount: true }));
+  readonly rootCategories$ = this.categoryService.getRootCategories()
+    .pipe(shareReplay({ bufferSize: 1, refCount: true }));
+  readonly selectedCategory$ = this.selectedCategoryId.pipe(
+    switchMap(categoryId => categoryId == null ? of(null) : this.categoryService.getCategoryById(categoryId)),
+    map(category => category ?? null),
+    shareReplay({ bufferSize: 1, refCount: true })
+  );
+  readonly breadcrumb$ = this.selectedCategoryId.pipe(
+    switchMap(categoryId => categoryId == null ? of([]) : this.categoryService.getBreadcrumb(categoryId)),
+    shareReplay({ bufferSize: 1, refCount: true })
+  );
+  readonly children$ = this.selectedCategoryId.pipe(
+    switchMap(categoryId => categoryId == null ? of([]) : this.categoryService.getChildren(categoryId)),
+    shareReplay({ bufferSize: 1, refCount: true })
+  );
+
+  loadCategories(): void {
+    this.loading.set(true);
+    this.error.set(null);
+
+    this.allCategories$.subscribe({
+      next: (categories) => {
+        this.allCategories.set(categories);
+        this.loading.set(false);
+      },
+      error: () => {
+        this.allCategories.set([]);
+        this.error.set('Failed to load categories');
+        this.loading.set(false);
+      }
+    });
+  }
+
+  selectCategory(categoryId: number | null): void {
+    this.selectedCategoryId.next(categoryId);
+  }
+
+  syncSelectedCategoryState(): void {
+    this.selectedCategory$.subscribe(category => this.selectedCategory.set(category));
+    this.breadcrumb$.subscribe(breadcrumb => this.breadcrumb.set(breadcrumb));
+    this.children$.subscribe(children => this.children.set(children));
+  }
+
+  getAllCategories(): Observable<Category[]> {
+    return this.allCategories$;
+  }
+
+  getCategoryTree(): Observable<Category[]> {
+    return this.categoryTree$;
+  }
+
+  getRootCategories(): Observable<Category[]> {
+    return this.rootCategories$;
+  }
+
+  getCategoryById(categoryId: number): Observable<Category | undefined> {
+    return this.categoryService.getCategoryById(categoryId);
+  }
+
+  getBreadcrumb(categoryId: number): Observable<Category[]> {
+    return this.categoryService.getBreadcrumb(categoryId);
+  }
+
+  getChildren(categoryId: number): Observable<Category[]> {
+    return this.categoryService.getChildren(categoryId);
+  }
+}