/**
 * Infrastructure Adapter: InMemoryStandingRepository
 * 
 * In-memory implementation of IStandingRepository.
 * Stores data in Map structure and calculates standings from race results.
 */

import { Standing } from '../../domain/entities/Standing';
import { IStandingRepository } from '../../application/ports/IStandingRepository';
import { IResultRepository } from '../../application/ports/IResultRepository';
import { IRaceRepository } from '../../application/ports/IRaceRepository';
import { ILeagueRepository } from '../../application/ports/ILeagueRepository';

/**
 * Points systems presets
 */
const POINTS_SYSTEMS: Record<string, Record<number, number>> = {
  'f1-2024': {
    1: 25, 2: 18, 3: 15, 4: 12, 5: 10,
    6: 8, 7: 6, 8: 4, 9: 2, 10: 1
  },
  'indycar': {
    1: 50, 2: 40, 3: 35, 4: 32, 5: 30,
    6: 28, 7: 26, 8: 24, 9: 22, 10: 20,
    11: 19, 12: 18, 13: 17, 14: 16, 15: 15
  }
};

export class InMemoryStandingRepository implements IStandingRepository {
  private standings: Map<string, Standing>;
  private resultRepository?: IResultRepository;
  private raceRepository?: IRaceRepository;
  private leagueRepository?: ILeagueRepository;

  constructor(
    seedData?: Standing[],
    resultRepository?: IResultRepository,
    raceRepository?: IRaceRepository,
    leagueRepository?: ILeagueRepository
  ) {
    this.standings = new Map();
    this.resultRepository = resultRepository;
    this.raceRepository = raceRepository;
    this.leagueRepository = leagueRepository;
    
    if (seedData) {
      seedData.forEach(standing => {
        const key = this.getKey(standing.leagueId, standing.driverId);
        this.standings.set(key, standing);
      });
    }
  }

  private getKey(leagueId: string, driverId: string): string {
    return `${leagueId}:${driverId}`;
  }

  async findByLeagueId(leagueId: string): Promise<Standing[]> {
    return Array.from(this.standings.values())
      .filter(standing => standing.leagueId === leagueId)
      .sort((a, b) => {
        // Sort by position (lower is better)
        if (a.position !== b.position) {
          return a.position - b.position;
        }
        // If positions are equal, sort by points (higher is better)
        return b.points - a.points;
      });
  }

  async findByDriverIdAndLeagueId(driverId: string, leagueId: string): Promise<Standing | null> {
    const key = this.getKey(leagueId, driverId);
    return this.standings.get(key) ?? null;
  }

  async findAll(): Promise<Standing[]> {
    return Array.from(this.standings.values());
  }

  async save(standing: Standing): Promise<Standing> {
    const key = this.getKey(standing.leagueId, standing.driverId);
    this.standings.set(key, standing);
    return standing;
  }

  async saveMany(standings: Standing[]): Promise<Standing[]> {
    standings.forEach(standing => {
      const key = this.getKey(standing.leagueId, standing.driverId);
      this.standings.set(key, standing);
    });
    return standings;
  }

  async delete(leagueId: string, driverId: string): Promise<void> {
    const key = this.getKey(leagueId, driverId);
    this.standings.delete(key);
  }

  async deleteByLeagueId(leagueId: string): Promise<void> {
    const toDelete = Array.from(this.standings.values())
      .filter(standing => standing.leagueId === leagueId);
    
    toDelete.forEach(standing => {
      const key = this.getKey(standing.leagueId, standing.driverId);
      this.standings.delete(key);
    });
  }

  async exists(leagueId: string, driverId: string): Promise<boolean> {
    const key = this.getKey(leagueId, driverId);
    return this.standings.has(key);
  }

  async recalculate(leagueId: string): Promise<Standing[]> {
    if (!this.resultRepository || !this.raceRepository || !this.leagueRepository) {
      throw new Error('Cannot recalculate standings: missing required repositories');
    }

    // Get league to determine points system
    const league = await this.leagueRepository.findById(leagueId);
    if (!league) {
      throw new Error(`League with ID ${leagueId} not found`);
    }

    // Get points system
    const pointsSystem = league.settings.customPoints ?? 
                        POINTS_SYSTEMS[league.settings.pointsSystem] ?? 
                        POINTS_SYSTEMS['f1-2024'];

    // Get all completed races for the league
    const races = await this.raceRepository.findCompletedByLeagueId(leagueId);
    
    // Get all results for these races
    const allResults = await Promise.all(
      races.map(race => this.resultRepository!.findByRaceId(race.id))
    );
    const results = allResults.flat();

    // Calculate standings per driver
    const standingsMap = new Map<string, Standing>();

    results.forEach(result => {
      let standing = standingsMap.get(result.driverId);
      
      if (!standing) {
        standing = Standing.create({
          leagueId,
          driverId: result.driverId,
        });
      }

      // Add points from this result
      standing = standing.addRaceResult(result.position, pointsSystem);
      standingsMap.set(result.driverId, standing);
    });

    // Sort by points and assign positions
    const sortedStandings = Array.from(standingsMap.values())
      .sort((a, b) => {
        if (b.points !== a.points) {
          return b.points - a.points;
        }
        // Tie-breaker: most wins
        if (b.wins !== a.wins) {
          return b.wins - a.wins;
        }
        // Tie-breaker: most races completed
        return b.racesCompleted - a.racesCompleted;
      });

    // Assign positions
    const updatedStandings = sortedStandings.map((standing, index) => 
      standing.updatePosition(index + 1)
    );

    // Save all standings
    await this.saveMany(updatedStandings);

    return updatedStandings;
  }

  /**
   * Get available points systems
   */
  static getPointsSystems(): Record<string, Record<number, number>> {
    return POINTS_SYSTEMS;
  }
}