// What the formula settings say about the usual participation (relecture of a576b68):
// the measured median, or twice C, even when the scale brings it back within its bounds.
import { describe, expect, it } from 'vitest';
import { usualShown } from '../../src/lib/participation';
import type { ParticipationInfo } from '../../src/lib/types';

const base: ParticipationInfo = {
  ratio: 0.3,
  source: 'median',
  sample: 5,
  median: 3,
  bounded: false,
  voters: 3,
  minSample: 5,
  windowDays: 365,
  everyHours: 24,
  bounds: [0.01, 0.5],
  measuredAt: null,
};

describe('usual participation as shown', () => {
  it('is the scale itself when nothing was bounded', () => {
    expect(usualShown(base, 10, 1)).toEqual({ voters: 3, ratio: 0.3 });
  });
  it('is the real median when the scale raised it to its floor', () => {
    const p = { ...base, median: 1, ratio: 0.01, voters: 57, bounded: true };
    expect(usualShown(p, 5745, 50)).toEqual({ voters: 1, ratio: 1 / 5745 });
  });
  it('is twice C for the reference, even when the scale lowered it to its ceiling', () => {
    const p = { ...base, source: 'reference' as const, median: null, sample: 0, ratio: 0.5, voters: 1, bounded: true };
    expect(usualShown(p, 2, 1)).toEqual({ voters: 2, ratio: 1 });
  });
  it('rounds a median between two numbers of voters, never its share', () => {
    const p = { ...base, median: 2.5, ratio: 0.01, voters: 57, bounded: true };
    expect(usualShown(p, 5745, 50).voters).toBe(3);
    // Relecture of 71819f9: the share is that of the median itself — 2,5 voters out of 4 is
    // 62,5 %, not 3 out of 4 (75 %).
    const q = { ...base, median: 2.5, ratio: 0.5, voters: 2, bounded: true };
    expect(usualShown(q, 4, 1)).toEqual({ voters: 3, ratio: 0.625 });
  });
  it('takes the share of twice C as it is, whatever the rounding', () => {
    const p = { ...base, source: 'reference' as const, median: null, sample: 0, ratio: 0.5, voters: 2, bounded: true };
    expect(usualShown(p, 3, 0.75)).toEqual({ voters: 2, ratio: 0.5 });
  });
});