import ascending from "./ascending.js";

export default function greatest(values, compare = ascending) {
  let max;
  let defined = false;
  if (compare.length === 1) {
    let maxValue;
    for (const element of values) {
      const value = compare(element);
      if (defined
          ? ascending(value, maxValue) > 0
          : ascending(value, value) === 0) {
        max = element;
        maxValue = value;
        defined = true;
      }
    }
  } else {
    for (const value of values) {
      if (defined
          ? compare(value, max) > 0
          : compare(value, value) === 0) {
        max = value;
        defined = true;
      }
    }
  }
  return max;
}