import {
  isSerializableObject,
  Serializable,
  SerializableArray,
  SerializableObject,
} from '../types';

function stringifyString(string: string, prefix?: string): string {
  if (!prefix) throw new TypeError('stringify expects an object');
  return `${prefix}=${encodeURIComponent(string)}`;
}

function stringifyArray(array: SerializableArray, prefix?: string): string {
  if (!prefix) throw new TypeError('stringify expects an object');
  const ret: string[] = [];
  for (let i = 0, l = array.length; i < l; i += 1) {
    ret.push(stringify(array[i], `${prefix}[${i}]`)); // eslint-disable-line no-use-before-define
  }
  return ret.join('&');
}

function stringifyObject(object: SerializableObject, prefix?: string): string {
  const ret: string[] = [];
  Object.keys(object).forEach((key) => {
    if (Object.prototype.hasOwnProperty.call(object, key)) {
      if (key === '') return;
      if (object[key] == null) {
        ret.push(prefix
          ? `${prefix}[${encodeURIComponent(key)}]=`
          : `${encodeURIComponent(key)}=`);
      } else {
        ret.push(stringify(object[key], prefix // eslint-disable-line no-use-before-define
          ? `${prefix}[${encodeURIComponent(key)}]`
          : encodeURIComponent(key)));
      }
    }
  });

  return ret.join('&');
}

export default function stringify(object: Serializable, prefix?: string): string {
  if (object === null) {
    return `${prefix || ''}=${encodeURIComponent(String(object))}`;
  } if (Array.isArray(object)) {
    return stringifyArray(object, prefix);
  } if (isSerializableObject(object)) {
    return stringifyObject(object, prefix);
  } if (typeof object === 'string') {
    return stringifyString(object, prefix);
  }

  return `${prefix || ''}=${encodeURIComponent(String(object))}`;
}