/// Use Case: Get Promotions
///
/// Retrieves the list of active promotional offers.
/// This use case encapsulates the business logic for fetching promotions.
///
/// Follows the Single Responsibility Principle - one use case, one operation.
library;

import 'package:worker/features/home/domain/entities/promotion.dart';
import 'package:worker/features/home/domain/repositories/home_repository.dart';

/// Get Promotions Use Case
///
/// Fetches active promotional offers to display on home screen.
///
/// Usage:
/// ```dart
/// final promotions = await getPromotions();
/// ```
///
/// This use case:
/// - Retrieves promotions from repository (which handles caching)
/// - Filters only active promotions
/// - Sorts by priority/date
/// - Returns list of Promotion entities
class GetPromotions {
  /// Home repository instance
  final HomeRepository repository;

  /// Constructor
  const GetPromotions(this.repository);

  /// Execute the use case
  ///
  /// Returns list of active [Promotion] objects.
  /// Returns empty list if no promotions available.
  ///
  /// Throws:
  /// - [NetworkException] if network error occurs
  /// - [CacheException] if local data corrupted
  Future<List<Promotion>> call() async {
    // Fetch promotions from repository
    final promotions = await repository.getPromotions();

    // TODO: Add business logic here if needed
    // For example:
    // - Filter only active promotions
    // - Sort by priority or start date
    // - Filter by user tier (Diamond exclusive promotions)
    // - Add personalization logic
    // - Log analytics events

    // Filter only active promotions
    final activePromotions = promotions
        .where((promotion) => promotion.isActive)
        .toList();

    // Sort by start date (newest first)
    activePromotions.sort((a, b) => b.startDate.compareTo(a.startDate));

    return activePromotions;
  }

  /// Execute with force refresh
  ///
  /// Forces a refresh from the server instead of using cached data.
  ///
  /// Use this when:
  /// - User explicitly pulls to refresh
  /// - Cached data is known to be stale
  /// - Need to show latest promotions immediately
  Future<List<Promotion>> refresh() async {
    final promotions = await repository.refreshPromotions();

    // Apply same filtering logic
    final activePromotions = promotions
        .where((promotion) => promotion.isActive)
        .toList();

    activePromotions.sort((a, b) => b.startDate.compareTo(a.startDate));

    return activePromotions;
  }
}