/**
 * Author: Simon-Pierre Boucher
 * Contact: contact@spboucher.ai
 * Project: Groupe Ka / Ka Maps
 *
 * Canadian-French price/value formatting shared by all map labels.
 */

/**
 * Compact price label for map markers, French-Canadian style.
 *
 *   289 000 $   → "289 k$"
 *   499 900 $   → "500 k$"
 *   1 250 000 $ → "1,25 M$"
 *   2 800 000 $ → "2,8 M$"
 *   950 $ (loyer) → "950 $"
 */
export function formatCompactPrice(value: number): string {
  if (!Number.isFinite(value) || value < 0) return "";
  if (value < 10_000) {
    // Rents and small amounts: whole dollars, non-breaking thin space groups.
    return `${formatGroupedInt(Math.round(value))} $`;
  }
  if (value < 1_000_000) {
    const k = Math.round(value / 1000);
    if (k >= 1000) return formatMillions(value); // 999 500+ rounds into M$
    return `${k} k$`;
  }
  return formatMillions(value);
}

function formatMillions(value: number): string {
  const m = value / 1_000_000;
  // Two decimals under 10 M$, one is enough above; strip trailing zeros.
  const rounded = m < 10 ? Math.round(m * 100) / 100 : Math.round(m * 10) / 10;
  const text = rounded
    .toFixed(rounded < 10 ? 2 : 1)
    .replace(/\.?0+$/, "")
    .replace(".", ",");
  return `${text} M$`;
}

/** Full price, French-Canadian: 589 000 $ (narrow no-break group separators). */
export function formatFullPrice(value: number): string {
  if (!Number.isFinite(value)) return "";
  return `${formatGroupedInt(Math.round(value))} $`;
}

/** Signed percentage, French style: +5,8 % / -1,2 %. */
export function formatPercent(ratio: number, decimals = 1): string {
  if (!Number.isFinite(ratio)) return "";
  const pct = ratio * 100;
  const sign = pct > 0 ? "+" : "";
  return `${sign}${pct.toFixed(decimals).replace(".", ",")} %`;
}

/** Group an integer with narrow no-break spaces: 1250000 → "1 250 000". */
function formatGroupedInt(n: number): string {
  const sign = n < 0 ? "-" : "";
  const digits = Math.abs(n).toString();
  const grouped = digits.replace(/\B(?=(\d{3})+(?!\d))/g, " ");
  return sign + grouped;
}

/** Median of a numeric array (returns undefined for empty input). */
export function median(values: number[]): number | undefined {
  const clean = values.filter((v) => Number.isFinite(v)).sort((a, b) => a - b);
  if (clean.length === 0) return undefined;
  const mid = Math.floor(clean.length / 2);
  return clean.length % 2 === 1
    ? clean[mid]
    : ((clean[mid - 1] as number) + (clean[mid] as number)) / 2;
}