import type { Logger } from '@core/shared/domain/Logger';
import { Result } from '@core/shared/domain/Result';
import type { ApplicationErrorCode } from '@core/shared/errors/ApplicationErrorCode';

import { Race } from '../../domain/entities/Race';
import type { Season } from '../../domain/entities/season/Season';
import { RaceRepository } from '../../domain/repositories/RaceRepository';
import { SeasonRepository } from '../../domain/repositories/SeasonRepository';
import { SeasonScheduleGenerator } from '../../domain/services/SeasonScheduleGenerator';

export type UpdateLeagueSeasonScheduleRaceInput = {
  leagueId: string;
  seasonId: string;
  raceId: string;
  track?: string;
  car?: string;
  scheduledAt?: Date;
};

export type UpdateLeagueSeasonScheduleRaceResult = {
  success: true;
};

export type UpdateLeagueSeasonScheduleRaceErrorCode =
  | 'SEASON_NOT_FOUND'
  | 'RACE_NOT_FOUND'
  | 'RACE_OUTSIDE_SEASON_WINDOW'
  | 'INVALID_INPUT'
  | 'REPOSITORY_ERROR';

export class UpdateLeagueSeasonScheduleRaceUseCase {
  constructor(private readonly seasonRepository: SeasonRepository,
    private readonly raceRepository: RaceRepository,
    private readonly logger: Logger) {}

  async execute(
    input: UpdateLeagueSeasonScheduleRaceInput,
  ): Promise<
    Result<
      UpdateLeagueSeasonScheduleRaceResult,
      ApplicationErrorCode<UpdateLeagueSeasonScheduleRaceErrorCode, { message: string }>
    >
  > {
    this.logger.debug('Updating league season schedule race', {
      leagueId: input.leagueId,
      seasonId: input.seasonId,
      raceId: input.raceId,
    });

    try {
      const season = await this.seasonRepository.findById(input.seasonId);
      if (!season || season.leagueId !== input.leagueId) {
        return Result.err({
          code: 'SEASON_NOT_FOUND',
          details: { message: 'Season not found for league' },
        });
      }

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

      const nextTrack = input.track ?? existing.track;
      const nextCar = input.car ?? existing.car;
      const nextScheduledAt = input.scheduledAt ?? existing.scheduledAt;

      if (!this.isWithinSeasonWindow(season, nextScheduledAt)) {
        return Result.err({
          code: 'RACE_OUTSIDE_SEASON_WINDOW',
          details: { message: 'Race scheduledAt is outside the season schedule window' },
        });
      }

      let updated: Race;
      try {
        updated = Race.create({
          id: existing.id,
          leagueId: existing.leagueId,
          track: nextTrack,
          car: nextCar,
          scheduledAt: nextScheduledAt,
          ...(existing.trackId !== undefined ? { trackId: existing.trackId } : {}),
          ...(existing.carId !== undefined ? { carId: existing.carId } : {}),
          sessionType: existing.sessionType,
          status: existing.status.toString(),
          ...(existing.strengthOfFieldNumber !== undefined ? { strengthOfField: existing.strengthOfFieldNumber } : {}),
          ...(existing.registeredCountNumber !== undefined ? { registeredCount: existing.registeredCountNumber } : {}),
          ...(existing.maxParticipantsNumber !== undefined ? { maxParticipants: existing.maxParticipantsNumber } : {}),
        });
      } catch (err) {
        const message = err instanceof Error ? err.message : 'Invalid race update';
        return Result.err({ code: 'INVALID_INPUT', details: { message } });
      }

      await this.raceRepository.update(updated);

      const result: UpdateLeagueSeasonScheduleRaceResult = { success: true };
      return Result.ok(result);
    } catch (err) {
      const error = err instanceof Error ? err : new Error('Unknown error');
      this.logger.error('Failed to update league season schedule race', error, {
        leagueId: input.leagueId,
        seasonId: input.seasonId,
        raceId: input.raceId,
      });

      return Result.err({
        code: 'REPOSITORY_ERROR',
        details: { message: error.message },
      });
    }
  }

  private isWithinSeasonWindow(season: Season, scheduledAt: Date): boolean {
    const { start, endInclusive } = this.getSeasonDateWindow(season);
    if (!start && !endInclusive) return true;

    const t = scheduledAt.getTime();
    if (start && t < start.getTime()) return false;
    if (endInclusive && t > endInclusive.getTime()) return false;
    return true;
  }

  private getSeasonDateWindow(season: Season): { start?: Date; endInclusive?: Date } {
    const start = season.startDate ?? season.schedule?.startDate;
    const window: { start?: Date; endInclusive?: Date } = {};

    if (start) {
      window.start = start;
    }

    if (season.endDate) {
      window.endInclusive = season.endDate;
      return window;
    }

    if (season.schedule) {
      const slots = SeasonScheduleGenerator.generateSlotsUpTo(
        season.schedule,
        season.schedule.plannedRounds,
      );
      const last = slots.at(-1);
      if (last?.scheduledAt) {
        window.endInclusive = last.scheduledAt;
      }
      return window;
    }

    return window;
  }
}