/**
 * @name lcfc - lower-cased-first-character
 *
 * @param obj - This parameter is the object that will be converted to the first letter of the keys in the object to lowercase.
 * @returns - Returns the object with the first letter of the keys in the object to lowercase.
 *
 * @example
 *
 * const obj = {
 *  Name: "Ali Veli",
 *  Age: 25,
 *  Address: {
 *    City: "İstanbul",
 *    Country: "Türkiye"
 *  }
 * }
 *
 * const newObj = lcfc(obj);
 *
 * console.log(newObj);
 *
 * // Output:
 * {
 *   name: "Ali Veli",
 *   age: 25,
 *   address: {
 *     city: "İstanbul",
 *     country: "Türkiye"
 *   }
 * }
 */
export default function lcfc<T>(obj: T): T {
  const newObj: any = {};
  if (!obj) {
    return obj;
  }
  Object.keys(obj).forEach((key) => {
    if (
      typeof obj[key as keyof T] === "object" &&
      !Array.isArray(obj[key as keyof T])
    ) {
      newObj[key.charAt(0).toLowerCase() + key.slice(1)] = lcfc(
        obj[key as keyof T],
      );
      return;
    }
    if (
      typeof obj[key as keyof T] === "object" &&
      Array.isArray(obj[key as keyof T])
    ) {
      newObj[key.charAt(0).toLowerCase() + key.slice(1)] = (
        obj[key as keyof T] as any[]
      ).map((item) => {
        return lcfc(item);
      });
      return;
    }
    newObj[key.charAt(0).toLowerCase() + key.slice(1)] = obj[key as keyof T];
  });
  return newObj as T;
}