import type { IRaceRepository } from '../../domain/repositories/IRaceRepository';
import type { IRaceRegistrationRepository } from '../../domain/repositories/IRaceRegistrationRepository';
import type { IResultRepository } from '../../domain/repositories/IResultRepository';
import type { IStandingRepository } from '../../domain/repositories/IStandingRepository';
import { Result as RaceResult } from '../../domain/entities/result/Result';
import { Standing } from '../../domain/entities/Standing';
import { RaceResultGenerator } from '../utils/RaceResultGenerator';
import { RatingUpdateService } from '@core/identity/domain/services/RatingUpdateService';
import { Result } from '@core/shared/application/Result';
import type { ApplicationErrorCode } from '@core/shared/errors/ApplicationErrorCode';
import type { UseCaseOutputPort } from '@core/shared/application/UseCaseOutputPort';

export interface CompleteRaceWithRatingsInput {
  raceId: string;
}

export type CompleteRaceWithRatingsResult = {
  raceId: string;
  ratingsUpdatedForDriverIds: string[];
};

export type CompleteRaceWithRatingsErrorCode =
  | 'RACE_NOT_FOUND'
  | 'NO_REGISTERED_DRIVERS'
  | 'ALREADY_COMPLETED'
  | 'RATING_UPDATE_FAILED'
  | 'REPOSITORY_ERROR';

interface DriverRatingProvider {
  getRatings(driverIds: string[]): Map<string, number>;
}

/**
 * Enhanced CompleteRaceUseCase that includes rating updates.
 */
export class CompleteRaceUseCaseWithRatings {
  constructor(
    private readonly raceRepository: IRaceRepository,
    private readonly raceRegistrationRepository: IRaceRegistrationRepository,
    private readonly resultRepository: IResultRepository,
    private readonly standingRepository: IStandingRepository,
    private readonly driverRatingProvider: DriverRatingProvider,
    private readonly ratingUpdateService: RatingUpdateService,
    private readonly output: UseCaseOutputPort<CompleteRaceWithRatingsResult>,
  ) {}

  async execute(command: CompleteRaceWithRatingsInput): Promise<
    Result<void, ApplicationErrorCode<CompleteRaceWithRatingsErrorCode, { message: string }>>
  > {
    try {
      const { raceId } = command;

      const race = await this.raceRepository.findById(raceId);
      if (!race) {
        return Result.err({
          code: 'RACE_NOT_FOUND',
          details: { message: 'Race not found' }
        });
      }

      if (race.status === 'completed') {
        return Result.err({
          code: 'ALREADY_COMPLETED',
          details: { message: 'Race already completed' }
        });
      }

      const registeredDriverIds = await this.raceRegistrationRepository.getRegisteredDrivers(raceId);
      if (registeredDriverIds.length === 0) {
        return Result.err({
          code: 'NO_REGISTERED_DRIVERS',
          details: { message: 'No registered drivers' }
        });
      }

      const driverRatings = this.driverRatingProvider.getRatings(registeredDriverIds);

      const results = RaceResultGenerator.generateRaceResults(raceId, registeredDriverIds, driverRatings);

      for (const result of results) {
        await this.resultRepository.create(result);
      }

      await this.updateStandings(race.leagueId, results);

      try {
        await this.updateDriverRatings(results, registeredDriverIds.length);
      } catch (error) {
        return Result.err({
          code: 'RATING_UPDATE_FAILED',
          details: {
            message: error instanceof Error ? error.message : 'Failed to update driver ratings',
          },
        });
      }

      const completedRace = race.complete();
      await this.raceRepository.update(completedRace);

      this.output.present({
        raceId,
        ratingsUpdatedForDriverIds: registeredDriverIds,
      });

      return Result.ok(undefined);
    } catch (error) {
      return Result.err({
        code: 'REPOSITORY_ERROR',
        details: {
          message: error instanceof Error ? error.message : 'Unknown error',
        },
      });
    }
  }

  private async updateStandings(leagueId: string, results: RaceResult[]): Promise<void> {
    const resultsByDriver = new Map<string, RaceResult[]>();
    for (const result of results) {
      const driverIdStr = result.driverId.toString();
      const existing = resultsByDriver.get(driverIdStr) || [];
      existing.push(result);
      resultsByDriver.set(driverIdStr, existing);
    }

    for (const [driverIdStr, driverResults] of resultsByDriver) {
      let standing = await this.standingRepository.findByDriverIdAndLeagueId(driverIdStr, leagueId);

      if (!standing) {
        standing = Standing.create({
          leagueId,
          driverId: driverIdStr,
        });
      }

      for (const result of driverResults) {
        standing = standing.addRaceResult(result.position.toNumber(), {
          1: 25,
          2: 18,
          3: 15,
          4: 12,
          5: 10,
          6: 8,
          7: 6,
          8: 4,
          9: 2,
          10: 1,
        });
      }

      await this.standingRepository.save(standing);
    }
  }

  private async updateDriverRatings(results: RaceResult[], totalDrivers: number): Promise<void> {
    const driverResults = results.map((result) => ({
      driverId: result.driverId.toString(),
      position: result.position.toNumber(),
      totalDrivers,
      incidents: result.incidents.toNumber(),
      startPosition: result.startPosition.toNumber(),
    }));

    await this.ratingUpdateService.updateDriverRatingsAfterRace(driverResults);
  }
}