import { describe, expect, it } from 'vitest';
import { rankEntities, percentiles, inputsHash } from '../src/rank.js';

describe('rankEntities', () => {
  it('is deterministic and handles ties with competition ranking', () => {
    const items = [
      { id: 'b', value: 10 },
      { id: 'a', value: 10 },
      { id: 'c', value: 5 },
      { id: 'd', value: 1 },
    ];
    const r = rankEntities(items);
    expect(r.map((x) => [x.id, x.rank])).toEqual([
      ['a', 1],
      ['b', 1],
      ['c', 3],
      ['d', 4],
    ]);
    expect(r[0]!.percentile).toBe(100);
    expect(r[3]!.percentile).toBe(0);
    expect(rankEntities([...items].reverse())).toEqual(r);
  });
  it('drops non-finite values and ranks ascending when requested', () => {
    const r = rankEntities([{ id: 'x', value: NaN }, { id: 'y', value: 2 }, { id: 'z', value: 1 }], { descending: false });
    expect(r.map((x) => x.id)).toEqual(['z', 'y']);
    expect(r[0]!.eligible).toBe(2);
  });
  it('percentiles and hash are stable', async () => {
    const items = [{ id: 'a', value: 3 }, { id: 'b', value: 1 }];
    expect(percentiles(items).get('a')).toBe(100);
    expect(await inputsHash(items)).toBe(await inputsHash([...items].reverse()));
  });
});