import { formatAmount } from "./format";

/**
 * Parses what a person types into an amount field ("1,25,000", "1250.5", "₹ 99.99") into integer paise
 * without going through floating point. Returns null for anything that is not a plain amount with at
 * most two decimals; an empty string is 0.
 */
export function parseRupeesToPaise(text: string): number | null {
  const cleaned = text.replace(/[₹,\s]/g, "");
  if (cleaned === "") return 0;
  const m = /^(\d+)(?:\.(\d{0,2}))?$/.exec(cleaned);
  if (!m) return null;
  const whole = Number(m[1]);
  const paise = whole * 100 + Number((m[2] ?? "").padEnd(2, "0"));
  return Number.isSafeInteger(paise) ? paise : null;
}

/** 123450 -> "1234.50", for filling an amount field. */
export function paiseToInput(paise: number): string {
  const p = Math.max(0, Math.round(paise));
  return `${Math.floor(p / 100)}.${String(p % 100).padStart(2, "0")}`;
}

/** 123450 -> "₹1,234.50" */
export function formatPaise(paise: number): string {
  return `₹${formatAmount(paise / 100)}`;
}