An implementation of Enigma in TypeScript with my weakest programming skill, AI co-autor

Enigma.ts

const base = 97;
const ALPHABET_LENGTH = 26;

const Rotor =
  (config: number) =>
  (plain: string): string => {
    if (plain < "a" || plain > "z") {
      return plain;
    }

    return String.fromCharCode(((plain.charCodeAt(0) - base + config) % ALPHABET_LENGTH) + base);
  };

const Reflector = (plain: string): string => {
  if (plain < "a" || plain > "z") {
    return plain;
  }

  return String.fromCharCode(ALPHABET_LENGTH - 1 - (plain.charCodeAt(0) - base) + base);
};

export const Enigma = (configs: number[]) => {
  const rotors = configs.map(Rotor);
  const reverseRotors = [...rotors].reverse();

  return (plain: string): string => {
    return plain
      .split("")
      .map((c) => rotors.reduce((t, rotor) => rotor(t), c))
      .map(Reflector)
      .map((c) => reverseRotors.reduce((t, rotor) => rotor(t), c))
      .join("");
  };
};