// @flow
import { Platform } from 'react-native';

// todo cleanup unused utilities from legacy code

// modeled after base64 web-safe chars, but ordered by ASCII
const PUSH_CHARS =
  '-0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz';
const AUTO_ID_CHARS =
  'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
const { hasOwnProperty } = Object;

// const DEFAULT_CHUNK_SIZE = 50;
/**
 * Checks for property existence by name on the specified object
 * @param object
 * @param property
 * @returns {*}
 */
export function hop(object: Object, property: string): boolean {
  return hasOwnProperty.call(object, property);
}

/**
 * Deep get a value from an object.
 * @website https://github.com/Salakar/deeps
 * @param object
 * @param path
 * @param joiner
 * @returns {*}
 */
export function deepGet(object: any, path: string, joiner?: string = '/'): any {
  if (!isObject(object) && !Array.isArray(object)) return undefined;
  const keys = path.split(joiner);

  let i = 0;
  let tmp = object;
  const len = keys.length;

  while (i < len) {
    const key = keys[i++];
    if (!tmp || !hasOwnProperty.call(tmp, key)) return undefined;
    tmp = tmp[key];
  }

  return tmp;
}

/**
 * Deep check if a key exists.
 * @website https://github.com/Salakar/deeps
 * @param object
 * @param path
 * @param joiner
 * @returns {*}
 */
export function deepExists(
  object: Object,
  path: string,
  joiner?: string = '/'
): boolean {
  const keys = path.split(joiner);

  let i = 0;
  let tmp = object;
  const len = keys.length;

  while (i < len) {
    const key = keys[i++];
    if (!tmp || !hasOwnProperty.call(tmp, key)) return false;
    tmp = tmp[key];
  }

  return tmp !== undefined;
}

/**
 * Deep Check if obj1 keys are contained in obj2
 * @param obj1
 * @param obj2
 * @returns {boolean}
 */
export function areObjectKeysContainedInOther(
  obj1: Object,
  obj2: Object
): boolean {
  if (!isObject(obj1) || !isObject(obj2)) {
    return false;
  }
  const keys1 = Object.keys(obj1);
  const keys2 = Object.keys(obj2);
  if (isArrayContainedInOther(keys1, keys2)) {
    return keys1
      .filter(key => isObject(obj1[key]))
      .reduce(
        (acc, cur) =>
          acc && areObjectKeysContainedInOther(obj1[cur], obj2[cur]),
        true
      );
  }
  return false;
}

/**
 * Check if arr1 is contained in arr2
 * @param arr1
 * @param arr2
 * @returns {boolean}
 */
export function isArrayContainedInOther(
  arr1: Array<*>,
  arr2: Array<*>
): boolean {
  if (!Array.isArray(arr1) || !Array.isArray(arr2)) {
    return false;
  }
  return arr1.reduce((acc, cur) => acc && arr2.includes(cur), true);
}

/**
 * Simple is object check.
 * @param item
 * @returns {boolean}
 */
export function isObject(item: mixed): boolean %checks {
  return item
    ? typeof item === 'object' && !Array.isArray(item) && item !== null
    : false;
}

/**
 * Simple is function check
 * @param item
 * @returns {*|boolean}
 */
export function isFunction(item?: mixed): boolean %checks {
  return item ? typeof item === 'function' : false;
}

/**
 * Simple is string check
 * @param value
 * @return {boolean}
 */
export function isString(value: mixed): boolean %checks {
  return typeof value === 'string';
}

/**
 * Simple is boolean check
 * @param value
 * @return {boolean}
 */
export function isBoolean(value: mixed): boolean %checks {
  return typeof value === 'boolean';
}

// platform checks
export const isIOS = Platform.OS === 'ios';
export const isAndroid = Platform.OS === 'android';

/**
 *
 * @param string
 * @returns {*}
 */
export function tryJSONParse(string: string | null): any {
  try {
    return string && JSON.parse(string);
  } catch (jsonError) {
    return string;
  }
}

/**
 *
 * @param data
 * @returns {*}
 */
export function tryJSONStringify(data: mixed): string | null {
  try {
    return JSON.stringify(data);
  } catch (jsonError) {
    return null;
  }
}

/**
 * No operation func
 */
export function noop(): void {}

/**
 * Remove a trailing forward slash from a string
 * @param str
 * @returns {*}
 */
export function stripTrailingSlash(str: string): string {
  if (!isString(str)) return str;
  return str.endsWith('/') ? str.slice(0, -1) : str;
}

/**
 * Returns a string typeof that's valid for Firebase usage
 * @param value
 * @return {*}
 */
export function typeOf(value: any): string {
  if (value === null) return 'null';
  if (Array.isArray(value)) return 'array';
  return typeof value;
}

// timestamp of last push, used to prevent local collisions if you push twice in one ms.
let lastPushTime = 0;

// we generate 72-bits of randomness which get turned into 12 characters and appended to the
// timestamp to prevent collisions with other clients.  We store the last characters we
// generated because in the event of a collision, we'll use those same characters except
// "incremented" by one.
const lastRandChars = [];

/**
 * Generate a firebase id - for use with ref().push(val, cb) - e.g. -KXMr7k2tXUFQqiaZRY4'
 * @param serverTimeOffset - pass in server time offset from native side
 * @returns {string}
 */
export function generatePushID(serverTimeOffset?: number = 0): string {
  const timeStampChars = new Array(8);
  let now = new Date().getTime() + serverTimeOffset;
  const duplicateTime = now === lastPushTime;

  lastPushTime = now;

  for (let i = 7; i >= 0; i -= 1) {
    timeStampChars[i] = PUSH_CHARS.charAt(now % 64);
    now = Math.floor(now / 64);
  }

  if (now !== 0)
    throw new Error('We should have converted the entire timestamp.');

  let id = timeStampChars.join('');

  if (!duplicateTime) {
    for (let i = 0; i < 12; i += 1) {
      lastRandChars[i] = Math.floor(Math.random() * 64);
    }
  } else {
    // if the timestamp hasn't changed since last push,
    // use the same random number, but increment it by 1.
    let i;
    for (i = 11; i >= 0 && lastRandChars[i] === 63; i -= 1) {
      lastRandChars[i] = 0;
    }

    lastRandChars[i] += 1;
  }

  for (let i = 0; i < 12; i++) {
    id += PUSH_CHARS.charAt(lastRandChars[i]);
  }

  if (id.length !== 20) throw new Error('Length should be 20.');

  return id;
}

/**
 * Converts a code and message from a native event to a JS Error
 * @param code
 * @param message
 * @param additionalProps
 * @returns {Error}
 */
export function nativeToJSError(
  code: string,
  message: string,
  additionalProps?: Object = {}
) {
  const error: Object = new Error(message);
  error.code = code;
  Object.assign(error, additionalProps);
  // exclude this function from the stack
  const _stackArray = error.stack.split('\n');
  error.stack = _stackArray.splice(1, _stackArray.length).join('\n');
  return error;
}

/**
 *
 * @param object
 * @return {string}
 */
export function objectToUniqueId(object: Object): string {
  if (!isObject(object) || object === null) return JSON.stringify(object);

  const keys = Object.keys(object).sort();

  let key = '{';
  for (let i = 0; i < keys.length; i++) {
    if (i !== 0) key += ',';
    key += JSON.stringify(keys[i]);
    key += ':';
    key += objectToUniqueId(object[keys[i]]);
  }

  key += '}';
  return key;
}

/**
 * Return the existing promise if no callback provided or
 * exec the promise and callback if optionalCallback is valid.
 *
 * @param promise
 * @param optionalCallback
 * @return {Promise}
 */
export function promiseOrCallback(
  promise: Promise<*>,
  optionalCallback?: Function
): Promise<*> {
  if (!isFunction(optionalCallback)) return promise;

  return promise
    .then(result => {
      // some of firebase internal tests & methods only check/return one arg
      // see https://github.com/firebase/firebase-js-sdk/blob/master/src/utils/promise.ts#L62
      if (optionalCallback && optionalCallback.length === 1) {
        optionalCallback(null);
      } else if (optionalCallback) {
        optionalCallback(null, result);
      }

      return Promise.resolve(result);
    })
    .catch(error => {
      if (optionalCallback) optionalCallback(error);
      return Promise.reject(error);
    });
}

/**
 * Generate a firestore auto id for use with collection/document .add()
 * @return {string}
 */
export function firestoreAutoId(): string {
  let autoId = '';

  for (let i = 0; i < 20; i++) {
    autoId += AUTO_ID_CHARS.charAt(
      Math.floor(Math.random() * AUTO_ID_CHARS.length)
    );
  }
  return autoId;
}