refactor

core/racing/application/use-cases/GetLeagueStatsUseCase.ts

@@ -1,28 +1,37 @@
 import type { ILeagueMembershipRepository } from '../../domain/repositories/ILeagueMembershipRepository';
 import type { IRaceRepository } from '../../domain/repositories/IRaceRepository';
-import type { ILeagueStatsPresenter, LeagueStatsResultDTO, LeagueStatsViewModel } from '../presenters/ILeagueStatsPresenter';
-import type { UseCase } from '@core/shared/application/UseCase';
+import type { LeagueStatsViewModel } from '../presenters/ILeagueStatsPresenter';
+import type { DriverRatingProvider } from '../ports/DriverRatingProvider';
+import { Result } from '@core/shared/application/Result';
+import type { ApplicationErrorCode } from '@core/shared/errors/ApplicationErrorCode';
 
 export interface GetLeagueStatsUseCaseParams {
   leagueId: string;
 }
 
-export class GetLeagueStatsUseCase implements UseCase<GetLeagueStatsUseCaseParams, LeagueStatsResultDTO, LeagueStatsViewModel, ILeagueStatsPresenter> {
+export class GetLeagueStatsUseCase {
   constructor(
     private readonly leagueMembershipRepository: ILeagueMembershipRepository,
     private readonly raceRepository: IRaceRepository,
+    private readonly driverRatingProvider: DriverRatingProvider,
   ) {}
 
-  async execute(params: GetLeagueStatsUseCaseParams, presenter: ILeagueStatsPresenter): Promise<void> {
-    const memberships = await this.leagueMembershipRepository.getLeagueMembers(params.leagueId);
-    const races = await this.raceRepository.findByLeagueId(params.leagueId);
-    // TODO: Implement average rating calculation from driver ratings
-    const dto: LeagueStatsResultDTO = {
-      totalMembers: memberships.length,
-      totalRaces: races.length,
-      averageRating: 0,
-    };
-    presenter.reset();
-    presenter.present(dto);
+  async execute(params: GetLeagueStatsUseCaseParams): Promise<Result<LeagueStatsViewModel, ApplicationErrorCode<'REPOSITORY_ERROR'>>> {
+    try {
+      const memberships = await this.leagueMembershipRepository.getLeagueMembers(params.leagueId);
+      const races = await this.raceRepository.findByLeagueId(params.leagueId);
+      const driverIds = memberships.map(m => m.driverId);
+      const ratings = this.driverRatingProvider.getRatings(driverIds);
+      const validRatings = Array.from(ratings.values()).filter(r => r !== null) as number[];
+      const averageRating = validRatings.length > 0 ? Math.round(validRatings.reduce((sum, r) => sum + r, 0) / validRatings.length) : 0;
+      const viewModel: LeagueStatsViewModel = {
+        totalMembers: memberships.length,
+        totalRaces: races.length,
+        averageRating,
+      };
+      return Result.ok(viewModel);
+    } catch {
+      return Result.err({ code: 'REPOSITORY_ERROR', message: 'Failed to fetch league stats' });
+    }
   }
 }