import { describe, expect, it } from 'vitest';
import { nlStats, activeSources, languageSignal, type NlStats } from './nl-stats';

// The identified total is a deduplicated DID union, never a sum. These invariants keep a bad
// aggregate (or an accidental sum) from shipping a wrong headline. The loader also enforces
// them at build time; this pins the behaviour and documents the contract.
describe('nl-stats aggregate', () => {
  const counts = Object.values(nlStats.identified.bySource);

  it('is a real dedupe: total is at least the largest single source', () => {
    expect(nlStats.identified.total).toBeGreaterThanOrEqual(Math.max(0, ...counts));
  });

  it('is a union, not a sum: total never exceeds the summed sources', () => {
    const sum = counts.reduce((a, b) => a + b, 0);
    expect(nlStats.identified.total).toBeLessThanOrEqual(sum);
  });

  it('exposes only the sources that have identified accounts', () => {
    for (const s of activeSources) {
      expect(nlStats.identified.bySource[s]).toBeGreaterThan(0);
    }
    const inactive = (['nlHandle', 'starterpack', 'sifaNl', 'sifaCompany'] as const).filter(
      (s) => !activeSources.includes(s),
    );
    for (const s of inactive) {
      expect(nlStats.identified.bySource[s]).toBe(0);
    }
  });

  // Language is a signal, never confirmation: Dutch is spoken in Belgium too, so "posted in
  // Dutch" cannot place an account in the Netherlands. It must stay out of the floor.
  it('never counts the language signal into the identified floor', () => {
    expect(Object.keys(nlStats.identified.bySource)).not.toContain('dutchPoster');
    if (languageSignal) {
      expect(languageSignal.count).toBeGreaterThan(0);
      // The floor may not silently absorb it: signalOnly accounts are outside the union.
      expect(languageSignal.alsoConfirmed).toBeLessThanOrEqual(nlStats.identified.total);
      expect(languageSignal.alsoConfirmed + languageSignal.signalOnly).toBe(languageSignal.count);
    }
  });

  it('carries an estimate tier with a positive modelled figure', () => {
    expect(nlStats.estimate.modelledNl).toBeGreaterThan(0);
    expect(nlStats.estimate.blueskyActive).toBeGreaterThan(0);
  });

  it('rejects a summed (non-deduped) total', () => {
    const bad = structuredClone(nlStats) as NlStats;
    bad.identified.bySource = { nlHandle: 100, starterpack: 100, sifaNl: 0, sifaCompany: 0 };
    bad.identified.total = 200; // sum, not a union
    // total (200) == sum (200) is allowed (no overlap); 201 is not.
    bad.identified.total = 201;
    const sum = Object.values(bad.identified.bySource).reduce((a, b) => a + b, 0);
    expect(bad.identified.total).toBeGreaterThan(sum);
  });
});