# Catalog Module Report

## Scope

Sprint 5 added a Catalog Module on the frozen platform architecture. No backend APIs, authentication, payment, or bootstrap contracts were changed.

The catalog uses existing domain boundaries:

- Category data: `CategoryFacade` -> `CategoryService` -> Category Repository -> existing `GET /category`
- Product data: `ProductFacade` -> `ProductDataService` -> Product Provider -> existing product/category item endpoints

## Implemented Module

### Catalog Container

- `src/app/features/website/catalog/containers/catalog-container.component.ts`
- `src/app/features/website/catalog/containers/catalog-container.component.html`
- `src/app/features/website/catalog/containers/catalog-container.component.scss`

Responsibilities implemented:

- Reads the route category id.
- Requests category data through `CategoryFacade` only.
- Requests product data through `ProductFacade` only.
- Determines whether the current category has child categories.
- Renders category grid when child categories exist.
- Renders product grid when no child categories exist.
- Supports root catalog entry with root categories.
- Handles loading, empty, and error states.
- Cancels prior category/product data subscriptions when the route changes.

No `HttpClient`, backend DTO, auth, payment, bootstrap, or tenant-specific logic is used in the container.

### Category Grid

- `src/app/features/website/catalog/components/category-grid/category-grid.component.ts`
- `src/app/features/website/catalog/components/category-grid/category-grid.component.html`
- `src/app/features/website/catalog/components/category-grid/category-grid.component.scss`

Reusable category grid implemented with:

- Input: `Category[]`
- Output: selected `Category`
- Responsive grid layout
- Domain model only
- No data fetching
- No backend DTOs

### Product Grid

- `src/app/features/website/catalog/components/product-grid/product-grid.component.ts`
- `src/app/features/website/catalog/components/product-grid/product-grid.component.html`
- `src/app/features/website/catalog/components/product-grid/product-grid.component.scss`

Reusable product grid implemented with:

- Input: `Product[]`
- Output: selected `Product`
- Output: add-to-cart payload
- Output: product preview id
- Responsive grid layout
- Uses existing reusable product card
- No `HttpClient`
- No backend DTOs

### Product Card Compatibility

- `src/app/components/product-card/product-card.component.ts`
- `src/app/components/product-card/product-card.component.html`

Updated the reusable product card to depend on the Product Domain type and added an explicit selected output.

The product card remains input/output-only and does not use services, storage, `HttpClient`, or environment configuration. It displays image, title, price, discount, badges, and stock.

### Catalog State

- `src/app/features/website/catalog/models/catalog-state.model.ts`

Prepared future state architecture for:

- Category
- Search
- Sort
- Price range
- Attributes
- Pagination
- Filters

Backend filtering was intentionally not implemented in this sprint.

## Navigation

Updated routes in `src/app/app.routes.ts`:

- `/catalog`
- `/catalog/:id`

Both routes load the same catalog container. Legacy category URLs redirect to the catalog route:

- `/category/:id` -> `/catalog/:id`
- `/category/:id/items` -> `/catalog/:id`

Home category links now point to `/catalog/:id`.

## Unlimited Category Depth

Unlimited nesting is supported by the Category Domain tree utilities from Sprint 4. The catalog container does not assume a fixed depth. For any category id, it asks `CategoryFacade.getChildren(categoryId)`:

- if children exist, it renders the category grid
- if no children exist, it loads the product grid

This same decision repeats for every category route depth.

## Localization

Added catalog translations in:

- `src/app/i18n/en.ts`
- `src/app/i18n/ru.ts`
- `src/app/i18n/hy.ts`
- `src/app/i18n/translations.ts`

## Validation

Completed checks:

- Unlimited category depth is supported through facade child lookup and recursive category domain tree utilities.
- Product grid is reusable and consumes `Product[]`.
- Category grid is reusable and consumes `Category[]`.
- Catalog components use domain models only.
- Catalog data requests go through facades only.
- DTOs remain isolated outside the catalog module.
- Catalog module has no `HttpClient` usage.
- Product card has no services, storage, `HttpClient`, or environment usage.
- Authentication was not modified.
- Payment was not modified.
- Bootstrap contracts were not modified.
- Backend APIs were not modified.

Build validation passed:

```bash
npm run build
```

## Stop Point

Catalog Module implementation is complete for Sprint 5. Stop here for approval before starting the next module or any Builder/Backoffice work.