'use strict';

/**
 * The forward adjudication of a bet made against the measurement.
 *
 * We serve the map that scored WORSE in-window, on an argument the sample
 * cannot test. These lock the rule that decides whether that argument survives —
 * written before any forward date exists, so the bar cannot drift toward
 * whichever answer arrives.
 */

const duel = require('../../src/services/model/calibrationDuel');

/** Forward rows where `edge` favours the shadow when positive. */
function rows(dates, perDate, edge, seed = 2) {
  let s = seed;
  const rnd = () => (s = (s * 1103515245 + 12345) % 2147483648) / 2147483648;
  const out = [];
  for (let d = 0; d < dates; d += 1) {
    for (let i = 0; i < perDate; i += 1) {
      const won = rnd() < 0.6 ? 1 : 0;
      const err = 0.25 + rnd() * 0.1;
      out.push({
        date: `2026-09-${String(d + 1).padStart(2, '0')}`,
        fitted_through: '2026-08-31',
        won,
        served: won ? 1 - err : err,
        shadow: won ? 1 - err + edge : err - edge,
      });
    }
  }
  return out;
}

describe('the rule is pre-registered and cannot be met early', () => {
  it('is PENDING below the forward-date bar, whatever the numbers say', () => {
    // Even with the shadow winning decisively, 5 dates is not a verdict.
    const v = duel.adjudicate(rows(5, 40, 0.15));
    expect(v.verdict).toBe('PENDING');
    expect(v.dates_needed).toBe(duel.MIN_FORWARD_DATES - 5);
    expect(v.action).toMatch(/keep serving/);
  });

  it('REFUTES the bet when isotonic wins out-of-window at the bar', () => {
    const v = duel.adjudicate(rows(12, 40, 0.15));
    expect(v.verdict).toBe('REFUTED');
    expect(v.ci[1]).toBeLessThan(0);
    expect(v.action).toMatch(/REVERT/);
  });

  it('UPHOLDS the bet when the served map is not beaten', () => {
    const v = duel.adjudicate(rows(12, 40, -0.15));
    expect(v.verdict).toBe('UPHELD');
    expect(v.action).toMatch(/keep serving/);
  });

  it('UPHOLDS on a tie — the burden is on refutation, not on us', () => {
    const v = duel.adjudicate(rows(12, 40, 0));
    expect(v.verdict).toBe('UPHELD');
  });
});

describe('only genuinely out-of-window dates count', () => {
  it('drops rows inside the fit window — that would score memorisation', () => {
    const inWindow = rows(12, 40, 0.15).map((r) => ({ ...r, fitted_through: '2026-12-31' }));
    const v = duel.adjudicate(inWindow);
    expect(v.verdict).toBe('PENDING');
    expect(v.forward_dates).toBe(0);
  });

  it('drops rows with no fit provenance rather than assuming they are forward', () => {
    const noProv = rows(12, 40, 0.15).map(({ fitted_through, ...r }) => r);
    expect(duel.adjudicate(noProv).forward_dates).toBe(0);
  });

  it('drops rows missing either map — a duel needs both entrants', () => {
    const half = rows(12, 40, 0.15).map((r) => ({ ...r, shadow: null }));
    expect(duel.adjudicate(half).forward_dates).toBe(0);
  });
});