var baseIteratee = require('./_baseIteratee'),
createInverter = require('./_createInverter');
/** Used for built-in method references. */
var objectProto = Object.prototype;
/** Used to check objects for own properties. */
var hasOwnProperty = objectProto.hasOwnProperty;
/**
* Used to resolve the
* [`toStringTag`](http://ecma-international.org/ecma-262/7.0/#sec-object.prototype.tostring)
* of values.
*/
var nativeObjectToString = objectProto.toString;
/**
* This method is like `_.invert` except that the inverted object is generated
* from the results of running each element of `object` thru `iteratee`. The
* corresponding inverted value of each inverted key is an array of keys
* responsible for generating the inverted value. The iteratee is invoked
* with one argument: (value).
*
* @static
* @memberOf _
* @since 4.1.0
* @category Object
* @param {Object} object The object to invert.
* @param {Function} [iteratee=_.identity] The iteratee invoked per element.
* @returns {Object} Returns the new inverted object.
* @example
*
* var object = { 'a': 1, 'b': 2, 'c': 1 };
*
* _.invertBy(object);
* // => { '1': ['a', 'c'], '2': ['b'] }
*
* _.invertBy(object, function(value) {
* return 'group' + value;
* });
* // => { 'group1': ['a', 'c'], 'group2': ['b'] }
*/
var invertBy = createInverter(function(result, value, key) {
if (value != null &&
typeof value.toString != 'function') {
value = nativeObjectToString.call(value);
}
if (hasOwnProperty.call(result, value)) {
result[value].push(key);
} else {
result[value] = [key];
}
}, baseIteratee);
module.exports = invertBy;