/**
 * rigor/validity-parity.test.js — possibilistic validity metadata.
 *
 * Pins the Cella-FVN-inspired validity layer:
 *   - every check result carries a validity block {label, operator, regime,
 *     sources, conflictMass, validifiedPossibility, nonMaxitive}
 *   - unlabeled relations default to heuristic; a labeled relation
 *     propagates its label through identity/max fusion
 *   - max (disjunctive) fusion preserves the weakest source label
 *   - interior OWA/averaging is non-maxitive and always heuristic
 *   - min (conjunctive) fusion is approximate at best, surfaces the
 *     conflict mass (1 - possibility), and exposes the arbitrary-regime
 *     validification min(1, K*possibility)
 *   - product-style operators (exclusion, defeasible) are always heuristic
 *   - reliability and validity are distinct: reliability stays the scalar
 *     confidence; validity tracks the epistemic label
 */
import { describe, it } from 'node:test';
import assert from 'node:assert/strict';
import { rigor } from '@rigor/core';
import { Arbiter } from '../../src/index.js';
import { buildValidity, mergeValidity, weakestValidity, DEFAULT_VALIDITY } from '../../src/core/validity.js';

const child = (r) => ({ type: 'direct', relation: r });

function mk() {
  const a = new Arbiter();
  a.addNode('u:0', 'user');
  a.addNode('d:0', 'doc');
  a.addNode('g:0', 'group');
  return a;
}

describe('Possibilistic validity metadata (rigor)', () => {
  it('FIXED: labels, operators, conflict mass, validification per kind', () => {
    // direct unlabeled -> heuristic identity
    {
      const a = mk();
      a.setRelationConfig('t', { type: 'direct', relation: 'r1' });
      a.addRelation('u:0', 'r1', 'd:0', { possibility: 0.8 });
      const r = a.check('u:0', 't', 'd:0');
      assert.equal(r.validity.label, 'heuristic');
      assert.equal(r.validity.operator, 'identity');
      assert.deepEqual(r.validity.sources, ['r1']);
      assert.equal(r.validity.conflictMass, 0);
    }
    // labeled direct propagates its label
    {
      const a = mk();
      a.setRelationConfig('t', { type: 'direct', relation: 'r1' });
      a.addRelation('u:0', 'r1', 'd:0', { possibility: 0.8, validity: 'finite_sample' });
      assert.equal(a.check('u:0', 't', 'd:0').validity.label, 'finite_sample');
    }
    // max fusion preserves the weakest source label
    {
      const a = mk();
      a.setRelationConfig('t', { union: [child('r1'), child('r2')] });
      a.addRelation('u:0', 'r1', 'd:0', { possibility: 0.8, validity: 'finite_sample' });
      a.addRelation('u:0', 'r2', 'd:0', { possibility: 0.5, validity: 'conformal' });
      const r = a.check('u:0', 't', 'd:0');
      assert.equal(r.validity.label, 'conformal', 'weakest label wins through max');
      assert.equal(r.validity.operator, 'max');
      assert.equal(r.validity.nonMaxitive, false);
    }
    // interior OWA is non-maxitive heuristic
    {
      const a = mk();
      a.setRelationConfig('t', { union: [child('r1'), child('r2')], aggregator: 'average' });
      a.addRelation('u:0', 'r1', 'd:0', { possibility: 0.8, validity: 'finite_sample' });
      a.addRelation('u:0', 'r2', 'd:0', { possibility: 0.5, validity: 'finite_sample' });
      const r = a.check('u:0', 't', 'd:0');
      assert.equal(r.validity.operator, 'owa');
      assert.equal(r.validity.nonMaxitive, true);
      assert.equal(r.validity.label, 'heuristic', 'averaging never claims validity');
    }
    // min fusion: approximate, conflict mass, validification
    {
      const a = mk();
      a.setRelationConfig('t', { intersection: [child('r1'), child('r2')] });
      a.addRelation('u:0', 'r1', 'd:0', { possibility: 0.8, validity: 'finite_sample' });
      a.addRelation('u:0', 'r2', 'd:0', { possibility: 0.5, validity: 'finite_sample' });
      const r = a.check('u:0', 't', 'd:0');
      assert.equal(r.validity.operator, 'min');
      assert.equal(r.validity.label, 'approximate', 'unvalidified conjunctive is approximate at best');
      assert.ok(Math.abs(r.validity.conflictMass - (1 - 0.5)) < 1e-9, 'conflict mass = 1 - possibility');
      assert.equal(r.validity.validifiedPossibility, 1, 'min(1, K*gamma) with K=2, gamma=0.5');
    }
    // product operators are heuristic even with labeled sources
    {
      const a = mk();
      a.setRelationConfig('t', { exclusion: [child('r1'), child('r2')] });
      a.addRelation('u:0', 'r1', 'd:0', { possibility: 0.8, validity: 'finite_sample' });
      a.addRelation('u:0', 'r2', 'd:0', { possibility: 0.5, validity: 'finite_sample' });
      assert.equal(a.check('u:0', 't', 'd:0').validity.label, 'heuristic');
      a.setRelationConfig('t2', { type: 'defeasible', when: child('r1'), unless: child('r2') });
      assert.equal(a.check('u:0', 't2', 'd:0').validity.label, 'heuristic');
    }
    // chain: conjunctive ranking with conflict surfacing
    {
      const a = mk();
      a.setRelationConfig('t', { type: 'chain', steps: [{ relation: 'member_of', direction: 'out' }, { relation: 'viewer', direction: 'out' }] });
      a.addRelation('u:0', 'member_of', 'g:0', { possibility: 0.9 });
      a.addRelation('g:0', 'viewer', 'd:0', { possibility: 0.6 });
      const r = a.check('u:0', 't', 'd:0');
      assert.equal(r.validity.operator, 'min');
      assert.ok(Math.abs(r.validity.conflictMass - 0.4) < 1e-9, 'chain conflict mass');
    }
    // reliability and validity stay distinct
    {
      const a = mk();
      a.setRelationConfig('t', { type: 'direct', relation: 'r1' });
      a.addRelation('u:0', 'r1', 'd:0', { possibility: 0.8, reliability: 0.42, validity: 'finite_sample' });
      const r = a.check('u:0', 't', 'd:0');
      assert.equal(r.reliability, 0.42, 'reliability unchanged');
      assert.equal(r.validity.label, 'finite_sample', 'validity independent of reliability');
    }
  });

  it('PROPERTY CAMPAIGN: helper semantics (weakest, merge, default identity)', async () => {
    const result = await rigor.campaign(
      [rigor.fn('helpers', (labels) => {
        const weakest = weakestValidity(labels);
        const merged = mergeValidity(labels.map(l => ({
          label: l, operator: 'max', regime: 'arbitrary', sources: ['r'], nonMaxitive: false, conflictMass: 0, validifiedPossibility: null
        })));
        const single = mergeValidity([{
          label: labels[0], operator: 'max', regime: 'arbitrary', sources: ['r'], nonMaxitive: false, conflictMass: 0, validifiedPossibility: null
        }]);
        return {
          weakest: weakestValidity([labels[0], weakest]),
          mergedWeakest: merged.label === weakest,
          singlePass: single === undefined ? false : single.label === labels[0],
          defaultIsFrozen: Object.isFrozen(DEFAULT_VALIDITY),
          buildPositional: buildValidity('min', ['a'], ['finite_sample'], 2, 0.5).validifiedPossibility === 1
        };
      }, rigor.args(rigor.gen.array(rigor.gen.oneOf(['finite_sample', 'anytime', 'conformal', 'approximate', 'heuristic', 'unknown']), 1, 4)))],
      rigor.crucible([
        rigor.invariant('helper invariants', ({ error, errorMessage, actual }) => !error && !errorMessage && Object.values(actual).every(Boolean))
      ])
    ).run({ effort: 200, seed: 'validity-helpers-2026', artifacts: { dir: '', persist: 'never' } });

    const inv = result.crucibleVerdict?.invariants?.find(i => i.name === 'helper invariants');
    assert.ok(inv && inv.passed, `validity helpers violated in ${inv?.failureCount} cases`);
  });
});