import { describe, expect, it } from 'vitest';
import { tenderFingerprint } from './tender-fingerprint';

/**
 * SCHEMA-03 (D-04) — pure fingerprint function. NULL-tolerant because the
 * live DB is 92.4% NULL estimatedValue / 15.7% NULL deadlineAt (13-RESEARCH
 * Pattern 4) — a fingerprint that requires those fields would never match
 * the overwhelming majority of real DÖE tenders.
 */
describe('tenderFingerprint', () => {
  const base = {
    buyerName: 'Stadt München',
    title: 'Neubau einer Kindertagesstätte',
    cpvDivisions: ['45', '71'],
    deadlineAt: null as Date | null,
    estimatedValue: null as number | null,
  };

  it('matches when title+buyer+cpv are equal and value+deadline are both NULL', () => {
    const a = tenderFingerprint({ ...base });
    const b = tenderFingerprint({ ...base });
    expect(a).toBe(b);
  });

  it('differs for a different title (collision guard, Pitfall 1)', () => {
    const a = tenderFingerprint(base);
    const b = tenderFingerprint({ ...base, title: 'Sanierung eines Kindergartens' });
    expect(a).not.toBe(b);
  });

  it('normalizes umlauts so "München" and "Muenchen" contribute the same text', () => {
    const a = tenderFingerprint({ ...base, buyerName: 'Stadt München' });
    const b = tenderFingerprint({ ...base, buyerName: 'Stadt Muenchen' });
    expect(a).toBe(b);
  });

  it('is order-independent and deduplicated for cpvDivisions', () => {
    const a = tenderFingerprint({ ...base, cpvDivisions: ['45', '71'] });
    const b = tenderFingerprint({ ...base, cpvDivisions: ['71', '45', '71'] });
    expect(a).toBe(b);
  });

  it('buckets estimatedValue by order of magnitude — 12000 and 15000 collide', () => {
    const a = tenderFingerprint({ ...base, estimatedValue: 12000 });
    const b = tenderFingerprint({ ...base, estimatedValue: 15000 });
    expect(a).toBe(b);
  });

  it('separates estimatedValue across a magnitude boundary', () => {
    const a = tenderFingerprint({ ...base, estimatedValue: 9000 });
    const b = tenderFingerprint({ ...base, estimatedValue: 90000 });
    expect(a).not.toBe(b);
  });

  it('returns a stable sha256 hex string (deterministic across runs)', () => {
    const result = tenderFingerprint(base);
    expect(result).toMatch(/^[a-f0-9]{64}$/);
  });

  it('treats a null buyerName as an empty segment, not a crash', () => {
    expect(() => tenderFingerprint({ ...base, buyerName: null })).not.toThrow();
    const a = tenderFingerprint({ ...base, buyerName: null });
    const b = tenderFingerprint({ ...base, buyerName: null });
    expect(a).toBe(b);
  });
});