/**
 * String normalization used by reconciliation (CLAUDE.md §69). Deterministic, no LLM.
 */

const GREEK: Record<string, string> = { α: 'alpha', β: 'beta', γ: 'gamma', δ: 'delta', κ: 'kappa', λ: 'lambda', μ: 'mu' };

export function stripDiacritics(s: string): string {
  return s.normalize('NFKD').replace(/[̀-ͯ]/g, '');
}

/** Lowercase, ASCII, punctuation → space, collapse whitespace. Keeps digits (G12C, HER2). */
export function normalizeLabel(input: string): string {
  let s = stripDiacritics(input).toLowerCase();
  s = s.replace(/[αβγδκλμ]/g, (c) => GREEK[c] ?? c);
  s = s.replace(/['’`"]/g, '');
  s = s.replace(/[^a-z0-9]+/g, ' ');
  s = s.replace(/\b(nos|unspecified|not otherwise specified)\b/g, ' ');
  s = s.replace(/\bcarcinomas\b/g, 'carcinoma').replace(/\bcancers\b/g, 'cancer').replace(/\btumou?rs\b/g, 'tumor').replace(/\btumour\b/g, 'tumor').replace(/\bneoplasms\b/g, 'neoplasm').replace(/\bsarcomas\b/g, 'sarcoma').replace(/\blymphomas\b/g, 'lymphoma').replace(/\bleukaemia\b/g, 'leukemia').replace(/\bleukemias\b/g, 'leukemia');
  return s.replace(/\s+/g, ' ').trim();
}

/** "Carcinoma, Non-Small-Cell Lung" (MeSH inverted form) → "Non-Small-Cell Lung Carcinoma". */
export function uninvertMeshTerm(term: string): string {
  const parts = term.split(',').map((p) => p.trim());
  if (parts.length < 2) return term;
  return [...parts.slice(1), parts[0]].join(' ');
}

/** URL slug for entity routes. */
export function slugify(input: string): string {
  return stripDiacritics(input)
    .toLowerCase()
    .replace(/[^a-z0-9]+/g, '-')
    .replace(/^-+|-+$/g, '')
    .slice(0, 120);
}

export function sha256Hex(data: string | Uint8Array): Promise<string> {
  return import('node:crypto').then(({ createHash }) => createHash('sha256').update(data).digest('hex'));
}