/**
 * Normalizes vehicle make and model names for human-friendly display.
 * - Replaces underscores with spaces
 * - Collapses whitespace
 * - Title-cases standard words
 * - Uppercases common acronyms (e.g., HD, GT, Z06)
 */

const MODEL_ACRONYMS = new Set([
  'HD','GT','GL','SE','LE','XLE','RS','SVT','XR','ST','FX4','TRD','ZR1','Z06','GTI','GLI','SI','SS','LT','LTZ','RT','SRT','SR','SR5','XSE','SEL'
]);

export function normalizeModelName(input?: string | null): string | undefined {
  if (input == null) return input ?? undefined;
  let s = String(input).replace(/_/g, ' ');
  s = s.replace(/\s+/g, ' ').trim();
  if (s.length === 0) return s;

  const tokens = s.split(' ');
  const normalized = tokens.map(t => {
    const raw = t;
    const upper = raw.toUpperCase();
    const lower = raw.toLowerCase();
    // Uppercase known acronyms (match case-insensitively)
    if (MODEL_ACRONYMS.has(upper)) return upper;
    // Tokens with letters+digits (e.g., Z06) – prefer uppercase
    if (/^[a-z0-9]+$/i.test(raw) && /[a-z]/i.test(raw) && /\d/.test(raw) && raw.length <= 4) {
      return upper;
    }
    // Pure letters: title case
    if (/^[a-z]+$/i.test(raw)) {
      return lower.charAt(0).toUpperCase() + lower.slice(1);
    }
    // Numbers or mixed/punctuated tokens: keep as-is except collapse case
    return raw;
  });
  return normalized.join(' ');
}

export function normalizeMakeName(input?: string | null): string | undefined {
  if (input == null) return input ?? undefined;
  const s = String(input).replace(/_/g, ' ').replace(/\s+/g, ' ').trim();
  if (s.length === 0) return s;
  const title = s.toLowerCase().split(' ').map(w => w.charAt(0).toUpperCase() + w.slice(1)).join(' ');
  // Special cases
  if (/^bmw$/i.test(s)) return 'BMW';
  if (/^gmc$/i.test(s)) return 'GMC';
  if (/^mini$/i.test(s)) return 'MINI';
  if (/^mclaren$/i.test(s)) return 'McLaren';
  return title;
}