import type { RudderContext } from '../core/context.js';
import { api } from '../generated/api.js';
import type { RankEntry } from '../generated/leaderboards.js';

/**
 * A cached handle for a specific leaderboard.
 *
 * Created by `LeaderboardsService.findBySlug()` — subsequent calls with
 * the same slug return the same handle, avoiding redundant fetches.
 */
export class LeaderboardHandle {
  private entries: RankEntry[] = [];

  constructor(
    public readonly slug: string,
    private readonly ctx: RudderContext,
  ) {}

  getEntries(): readonly RankEntry[] {
    return this.entries;
  }

  async submit(score: number): Promise<void> {
    return api.submitScore(this.ctx, { slug: this.slug }, { slug: this.slug, score });
  }

  async list(limit = 100): Promise<readonly RankEntry[]> {
    const response = await api.getRanking(
      this.ctx,
      { slug: this.slug },
      { limit: limit > 0 ? limit : undefined },
    );
    this.entries = response.entries ?? [];
    return this.entries;
  }
}

export class LeaderboardsService {
  private readonly cache = new Map<string, LeaderboardHandle>();

  constructor(private readonly ctx: RudderContext) {}

  /** Returns a cached handle for the given leaderboard slug. */
  findBySlug(slug: string): LeaderboardHandle {
    let handle = this.cache.get(slug);
    if (!handle) {
      handle = new LeaderboardHandle(slug, this.ctx);
      this.cache.set(slug, handle);
    }
    return handle;
  }
}