/**
 * Formatting. Indian conventions throughout, because the numbers in this app
 * are rupee amounts read by Indian bankers.
 *
 * `en-IN` grouping is not cosmetic: ₹18,00,000 is how eighteen lakh is written,
 * and ₹1,800,000 reads as a foreign system's idea of the same number. The
 * lakh/crore short forms exist because a queue column has no room for eight
 * digits and "₹18.0 L" is what a person would say out loud.
 */

const INR = new Intl.NumberFormat('en-IN', { maximumFractionDigits: 0 });

export function num(v: unknown): number | null {
  if (v === null || v === undefined || v === '') return null;
  const n = Number(v);
  return Number.isFinite(n) ? n : null;
}

export function str(v: unknown): string {
  if (v === null || v === undefined) return '';
  return String(v);
}

/** ₹18,00,000 */
export function money(v: unknown): string {
  const n = num(v);
  return n === null ? '—' : `₹${INR.format(n)}`;
}

/** ₹18.0 L / ₹1.25 Cr — for columns and tiles. */
export function moneyShort(v: unknown): string {
  const n = num(v);
  if (n === null) return '—';
  if (Math.abs(n) >= 1e7) return `₹${(n / 1e7).toFixed(2)} Cr`;
  if (Math.abs(n) >= 1e5) return `₹${(n / 1e5).toFixed(1)} L`;
  return `₹${INR.format(n)}`;
}

/** 44.3% */
export function pct(v: unknown, digits = 1): string {
  const n = num(v);
  return n === null ? '—' : `${n.toFixed(digits)}%`;
}

/** A stored ratio (0.7445) shown as a percentage. */
export function ratioPct(v: unknown, digits = 1): string {
  const n = num(v);
  return n === null ? '—' : `${(n * 100).toFixed(digits)}%`;
}

/** 1.34 */
export function ratio(v: unknown, digits = 2): string {
  const n = num(v);
  return n === null ? '—' : n.toFixed(digits);
}

export function dateTime(v: unknown): string {
  const s = str(v);
  if (!s) return '—';
  const d = new Date(s);
  if (Number.isNaN(d.getTime())) return s;
  return d.toLocaleString('en-IN', {
    day: '2-digit',
    month: 'short',
    year: 'numeric',
    hour: '2-digit',
    minute: '2-digit',
  });
}

export function dateOnly(v: unknown): string {
  const s = str(v);
  if (!s) return '—';
  const d = new Date(s);
  if (Number.isNaN(d.getTime())) return s;
  return d.toLocaleDateString('en-IN', { day: '2-digit', month: 'short', year: 'numeric' });
}

/** "msme" → "MSME / Business". Product codes are stored, not displayed. */
export function productLabel(v: unknown): string {
  const s = str(v);
  if (s === 'msme') return 'MSME / Business';
  if (s === 'personal') return 'Personal';
  return s || '—';
}

export function relationshipLabel(v: unknown): string {
  const s = str(v);
  if (s === 'new_to_bank') return 'New to Bank';
  if (s === 'existing') return 'Existing Customer';
  return s || '—';
}

/**
 * The assessment's reason codes arrive as one pipe-delimited string, because
 * that is the shape a customJS node can return without inventing a schema.
 * Split for display — a wall of pipes is unreadable, and each code is a
 * separate finding a credit manager weighs separately.
 */
export function reasonCodes(v: unknown): string[] {
  return str(v)
    .split('|')
    .map((s) => s.trim())
    .filter(Boolean);
}