import { UsersRankService } from '../../backend/src/modules/users/users-rank.service';

function buildMockManager(opts: { pointsByUser?: Map<string, number>; usersAhead?: number }): any {
  const pointsByUser = opts.pointsByUser ?? new Map();
  const usersAhead = opts.usersAhead ?? 0;
  const repo: any = {
    createQueryBuilder: jest.fn().mockImplementation((alias: string) => {
      const builder: any = {};
      builder.select = jest.fn().mockReturnThis();
      builder.addSelect = jest.fn().mockReturnThis();
      builder.where = jest.fn().mockReturnThis();
      builder.groupBy = jest.fn().mockReturnThis();
      builder.having = jest.fn().mockReturnThis();
      builder.getRawOne = jest.fn().mockImplementation(async () => {
        return { total: pointsByUser.get(alias === 's' ? '_self_' : '_self_') ?? 0 };
      });
      builder.getRawOneForUser = jest.fn().mockImplementation(async (userId: string) => {
        return { total: pointsByUser.get(userId) ?? 0 };
      });
      builder.getRawMany = jest.fn().mockImplementation(async () => {
        return Array.from({ length: usersAhead }, (_, i) => ({ userId: 'other_' + i }));
      });
      return builder;
    }),
  };
  // Wire the user's id into the "self" lookup.
  return {
    getRepository: () => ({
      createQueryBuilder: () => {
        const b: any = {};
        b.select = jest.fn().mockReturnThis();
        b.addSelect = jest.fn().mockReturnThis();
        b.where = jest.fn((q: string, p: any) => {
          b._userId = p?.userId;
          return b;
        });
        b.groupBy = jest.fn().mockReturnThis();
        b.having = jest.fn().mockReturnThis();
        b.getRawOne = jest.fn().mockImplementation(async () => {
          return { total: pointsByUser.get(b._userId) ?? 0 };
        });
        b.getRawMany = jest.fn().mockImplementation(async () => {
          return Array.from({ length: usersAhead }, (_, i) => ({ userId: 'other_' + i }));
        });
        return b;
      },
    }),
  };
}

describe('UsersRankService.rankOfUser', () => {
  it('returns null rank and 0 points for a user with no solves', async () => {
    const svc = new UsersRankService();
    const r = await svc.rankOfUser(buildMockManager({}) as any, 'u1');
    expect(r.rank).toBeNull();
    expect(r.points).toBe(0);
  });

  it('returns rank 1 when no users are ahead', async () => {
    const svc = new UsersRankService();
    const r = await svc.rankOfUser(buildMockManager({ pointsByUser: new Map([['u1', 100]]), usersAhead: 0 }) as any, 'u1');
    expect(r.rank).toBe(1);
    expect(r.points).toBe(100);
  });

  it('returns rank = ahead+1', async () => {
    const svc = new UsersRankService();
    const r = await svc.rankOfUser(buildMockManager({ pointsByUser: new Map([['u1', 100]]), usersAhead: 2 }) as any, 'u1');
    expect(r.rank).toBe(3);
    expect(r.points).toBe(100);
  });
});