'use strict';

var bind = require("./helpers/bind");

var isBuffer = require('is-buffer');
/*global toString:true*/
// utils is a library of generic helper functions non-specific to axios


var toString = Object.prototype.toString;
/**
 * Determine if a value is an Array
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is an Array, otherwise false
 */

function isArray(val) {
  return toString.call(val) === '[object Array]';
}
/**
 * Determine if a value is an ArrayBuffer
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is an ArrayBuffer, otherwise false
 */


function isArrayBuffer(val) {
  return toString.call(val) === '[object ArrayBuffer]';
}
/**
 * Determine if a value is a FormData
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is an FormData, otherwise false
 */


function isFormData(val) {
  return typeof FormData !== 'undefined' && val instanceof FormData;
}
/**
 * Determine if a value is a view on an ArrayBuffer
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a view on an ArrayBuffer, otherwise false
 */


function isArrayBufferView(val) {
  var result;

  if (typeof ArrayBuffer !== 'undefined' && ArrayBuffer.isView) {
    result = ArrayBuffer.isView(val);
  } else {
    result = val && val.buffer && val.buffer instanceof ArrayBuffer;
  }

  return result;
}
/**
 * Determine if a value is a String
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a String, otherwise false
 */


function isString(val) {
  return typeof val === 'string';
}
/**
 * Determine if a value is a Number
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a Number, otherwise false
 */


function isNumber(val) {
  return typeof val === 'number';
}
/**
 * Determine if a value is undefined
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if the value is undefined, otherwise false
 */


function isUndefined(val) {
  return typeof val === 'undefined';
}
/**
 * Determine if a value is an Object
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is an Object, otherwise false
 */


function isObject(val) {
  return val !== null && typeof val === 'object';
}
/**
 * Determine if a value is a Date
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a Date, otherwise false
 */


function isDate(val) {
  return toString.call(val) === '[object Date]';
}
/**
 * Determine if a value is a File
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a File, otherwise false
 */


function isFile(val) {
  return toString.call(val) === '[object File]';
}
/**
 * Determine if a value is a Blob
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a Blob, otherwise false
 */


function isBlob(val) {
  return toString.call(val) === '[object Blob]';
}
/**
 * Determine if a value is a Function
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a Function, otherwise false
 */


function isFunction(val) {
  return toString.call(val) === '[object Function]';
}
/**
 * Determine if a value is a Stream
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a Stream, otherwise false
 */


function isStream(val) {
  return isObject(val) && isFunction(val.pipe);
}
/**
 * Determine if a value is a URLSearchParams object
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a URLSearchParams object, otherwise false
 */


function isURLSearchParams(val) {
  return typeof URLSearchParams !== 'undefined' && val instanceof URLSearchParams;
}
/**
 * Trim excess whitespace off the beginning and end of a string
 *
 * @param {String} str The String to trim
 * @returns {String} The String freed of excess whitespace
 */


function trim(str) {
  return str.replace(/^\s*/, '').replace(/\s*$/, '');
}
/**
 * Determine if we're running in a standard browser environment
 *
 * This allows axios to run in a web worker, and react-native.
 * Both environments support XMLHttpRequest, but not fully standard globals.
 *
 * web workers:
 *  typeof window -> undefined
 *  typeof document -> undefined
 *
 * react-native:
 *  navigator.product -> 'ReactNative'
 */


function isStandardBrowserEnv() {
  if (typeof navigator !== 'undefined' && navigator.product === 'ReactNative') {
    return false;
  }

  return typeof window !== 'undefined' && typeof document !== 'undefined';
}
/**
 * Iterate over an Array or an Object invoking a function for each item.
 *
 * If `obj` is an Array callback will be called passing
 * the value, index, and complete array for each item.
 *
 * If 'obj' is an Object callback will be called passing
 * the value, key, and complete object for each property.
 *
 * @param {Object|Array} obj The object to iterate
 * @param {Function} fn The callback to invoke for each item
 */


function forEach(obj, fn) {
  // Don't bother if no value provided
  if (obj === null || typeof obj === 'undefined') {
    return;
  } // Force an array if not already something iterable


  if (typeof obj !== 'object') {
    /*eslint no-param-reassign:0*/
    obj = [obj];
  }

  if (isArray(obj)) {
    // Iterate over array values
    for (var i = 0, l = obj.length; i < l; i++) {
      fn.call(null, obj[i], i, obj);
    }
  } else {
    // Iterate over object keys
    for (var key in obj) {
      if (Object.prototype.hasOwnProperty.call(obj, key)) {
        fn.call(null, obj[key], key, obj);
      }
    }
  }
}
/**
 * Accepts varargs expecting each argument to be an object, then
 * immutably merges the properties of each object and returns result.
 *
 * When multiple objects contain the same key the later object in
 * the arguments list will take precedence.
 *
 * Example:
 *
 * ```js
 * var result = merge({foo: 123}, {foo: 456});
 * console.log(result.foo); // outputs 456
 * ```
 *
 * @param {Object} obj1 Object to merge
 * @returns {Object} Result of all merge properties
 */


function merge()
/* obj1, obj2, obj3, ... */
{
  var result = {};

  function assignValue(val, key) {
    if (typeof result[key] === 'object' && typeof val === 'object') {
      result[key] = merge(result[key], val);
    } else {
      result[key] = val;
    }
  }

  for (var i = 0, l = arguments.length; i < l; i++) {
    forEach(arguments[i], assignValue);
  }

  return result;
}
/**
 * Extends object a by mutably adding to it the properties of object b.
 *
 * @param {Object} a The object to be extended
 * @param {Object} b The object to copy properties from
 * @param {Object} thisArg The object to bind function to
 * @return {Object} The resulting value of object a
 */


function extend(a, b, thisArg) {
  forEach(b, function assignValue(val, key) {
    if (thisArg && typeof val === 'function') {
      a[key] = bind(val, thisArg);
    } else {
      a[key] = val;
    }
  });
  return a;
}

module.exports = {
  isArray: isArray,
  isArrayBuffer: isArrayBuffer,
  isBuffer: isBuffer,
  isFormData: isFormData,
  isArrayBufferView: isArrayBufferView,
  isString: isString,
  isNumber: isNumber,
  isObject: isObject,
  isUndefined: isUndefined,
  isDate: isDate,
  isFile: isFile,
  isBlob: isBlob,
  isFunction: isFunction,
  isStream: isStream,
  isURLSearchParams: isURLSearchParams,
  isStandardBrowserEnv: isStandardBrowserEnv,
  forEach: forEach,
  merge: merge,
  extend: extend,
  trim: trim
};