declare global {
  interface Array<T> {
    pushUnique(element: T): void;
    sample(): T;
    ignoreCaseIncludes(searchElement: any, fromIndex: any): any;
  }

  interface String {
    capitalize();
    capitalizeAll();
    lowerCaseFirst();
  }
}

Array.prototype.ignoreCaseIncludes = function(searchElement, fromIndex) {
  if (this == null) { throw new TypeError('"this" is null or not defined'); }
  return this.map((el) => el.toLowerCase()).includes(searchElement.toLowerCase(), fromIndex);
};

// only push unique elements
Array.prototype.pushUnique = function(element) {
  if (this.indexOf(element) === -1) { this.push(element); }
};

// grab a random element
Array.prototype.sample = function() {
  return this[Math.floor(Math.random() * this.length)];
};

String.prototype.capitalize = function() {
  if (this == null) { throw new TypeError('"this" is null or not defined'); }
  return this.charAt(0).toUpperCase() + this.slice(1).toLowerCase();
};

String.prototype.capitalizeAll = function() {
  if (this == null) { throw new TypeError('"this" is null or not defined'); }
  if (this.includes("-")) { return this.split("-").map((word) => word.capitalize()).join("-"); }
  return this.split(" ").map((word) => word.capitalize()).join(" ");
};

String.prototype.lowerCaseFirst = function() {
  if (this.charAt(0) === "I") { return this; }
  return this.charAt(0).toLowerCase() + this.slice(1);
};

export default {};