// Small formatting helpers shared by the UI, ported from
// scripts/classes/text_format.gd.

export function groupDigits(value) {
  const truncated = Math.trunc(value);
  const digits = String(Math.abs(truncated));
  let grouped = "";
  let count = 0;
  for (let i = digits.length - 1; i >= 0; i--) {
    grouped = digits[i] + grouped;
    count += 1;
    if (count % 3 === 0 && i > 0) grouped = " " + grouped;
  }
  return (truncated < 0 ? "-" : "") + grouped;
}

function threeSignificant(value) {
  const digits = Math.floor(Math.log(value) / Math.log(10)) + 1;
  const decimals = Math.max(0, 3 - digits);
  const factor = Math.pow(10, decimals);
  const rounded = Math.round(value * factor) / factor;
  let text = rounded.toFixed(decimals);
  if (text.includes(".")) text = text.replace(/0+$/, "").replace(/\.$/, "");
  return text;
}

export function compact(value) {
  if (Math.abs(value) < 1e-9) return "0";
  const sign = value < 0 ? "-" : "";
  let amount = Math.abs(value);
  const suffixes = ["", "K", "M", "B", "T"];
  let index = 0;
  while (amount >= 1000 && index < suffixes.length - 1) {
    amount /= 1000;
    index += 1;
  }
  let text = threeSignificant(amount);
  if (text === "1000" && index < suffixes.length - 1) {
    index += 1;
    text = "1";
  }
  return sign + text + suffixes[index];
}

export function improvements(list) {
  if (!list || list.length === 0) return "None";
  return list.join(", ");
}

export function hours(value) {
  if (value < 1.0) return value.toFixed(2) + " h";
  return value.toFixed(1) + " h";
}