var baseIsEqual = require('../internal/baseIsEqual'),
    bindCallback = require('../internal/bindCallback'),
    isStrictComparable = require('../internal/isStrictComparable');

/**
 * Performs a deep comparison between two values to determine if they are
 * equivalent. If `customizer` is provided it is invoked to compare values.
 * If `customizer` returns `undefined` comparisons are handled by the method
 * instead. The `customizer` is bound to `thisArg` and invoked with three
 * arguments: (value, other [, index|key]).
 *
 * **Note:** This method supports comparing arrays, booleans, `Date` objects,
 * numbers, `Object` objects, regexes, and strings. Objects are compared by
 * their own, not inherited, enumerable properties. Functions and DOM nodes
 * are **not** supported. Provide a customizer function to extend support
 * for comparing other values.
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to compare.
 * @param {*} other The other value to compare.
 * @param {Function} [customizer] The function to customize value comparisons.
 * @param {*} [thisArg] The `this` binding of `customizer`.
 * @returns {boolean} Returns `true` if the values are equivalent, else `false`.
 * @example
 *
 * var object = { 'user': 'fred' };
 * var other = { 'user': 'fred' };
 *
 * object == other;
 * // => false
 *
 * _.isEqual(object, other);
 * // => true
 *
 * // using a customizer callback
 * var array = ['hello', 'goodbye'];
 * var other = ['hi', 'goodbye'];
 *
 * _.isEqual(array, other, function(value, other) {
 *   if (_.every([value, other], RegExp.prototype.test, /^h(?:i|ello)$/)) {
 *     return true;
 *   }
 * });
 * // => true
 */
function isEqual(value, other, customizer, thisArg) {
  customizer = typeof customizer == 'function' && bindCallback(customizer, thisArg, 3);
  if (!customizer && isStrictComparable(value) && isStrictComparable(other)) {
    return value === other;
  }
  var result = customizer ? customizer(value, other) : undefined;
  return result === undefined ? baseIsEqual(value, other, customizer) : !!result;
}

module.exports = isEqual;
