"use strict";

function _typeof(obj) {

  if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") {

    _typeof = function (obj) {

      return typeof obj;

    };

  } else {

    _typeof = function (obj) {

      return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj;

    };

  }

  return _typeof(obj);

}

function _classCallCheck(instance, Constructor) {

  if (!(instance instanceof Constructor)) {

    throw new TypeError("Cannot call a class as a function");

  }

}

function _defineProperties(target, props) {

  for (var i = 0; i < props.length; i++) {

    var descriptor = props[i];

    descriptor.enumerable = descriptor.enumerable || false;

    descriptor.configurable = true;

    if ("value" in descriptor) descriptor.writable = true;

    Object.defineProperty(target, descriptor.key, descriptor);

  }

}

function _createClass(Constructor, protoProps, staticProps) {

  if (protoProps) _defineProperties(Constructor.prototype, protoProps);

  if (staticProps) _defineProperties(Constructor, staticProps);

  return Constructor;

}

/**

 * Given an instance of EquivalentKeyMap, returns its internal value pair tuple

 * for a key, if one exists. The tuple members consist of the last reference

 * value for the key (used in efficient subsequent lookups) and the value

 * assigned for the key at the leaf node.

 *

 * @param {EquivalentKeyMap} instance EquivalentKeyMap instance.

 * @param {*} key                     The key for which to return value pair.

 *

 * @return {?Array} Value pair, if exists.

 */

function getValuePair(instance, key) {

  var _map = instance._map,

      _arrayTreeMap = instance._arrayTreeMap,

      _objectTreeMap = instance._objectTreeMap; // Map keeps a reference to the last object-like key used to set the

  // value, which can be used to shortcut immediately to the value.

  if (_map.has(key)) {

    return _map.get(key);

  } // Sort keys to ensure stable retrieval from tree.

  var properties = Object.keys(key).sort(); // Tree by type to avoid conflicts on numeric object keys, empty value.

  var map = Array.isArray(key) ? _arrayTreeMap : _objectTreeMap;

  for (var i = 0; i < properties.length; i++) {

    var property = properties[i];

    map = map.get(property);

    if (map === undefined) {

      return;

    }

    var propertyValue = key[property];

    map = map.get(propertyValue);

    if (map === undefined) {

      return;

    }

  }

  var valuePair = map.get('_ekm_value');

  if (!valuePair) {

    return;

  } // If reached, it implies that an object-like key was set with another

  // reference, so delete the reference and replace with the current.

  _map.delete(valuePair[0]);

  valuePair[0] = key;

  map.set('_ekm_value', valuePair);

  _map.set(key, valuePair);

  return valuePair;

}

/**

 * Variant of a Map object which enables lookup by equivalent (deeply equal)

 * object and array keys.

 */

var EquivalentKeyMap =

/*#__PURE__*/

function () {

  /**

   * Constructs a new instance of EquivalentKeyMap.

   *

   * @param {Iterable.<*>} iterable Initial pair of key, value for map.

   */

  function EquivalentKeyMap(iterable) {

    _classCallCheck(this, EquivalentKeyMap);

    this.clear();

    if (iterable instanceof EquivalentKeyMap) {

      // Map#forEach is only means of iterating with support for IE11.

      var iterablePairs = [];

      iterable.forEach(function (value, key) {

        iterablePairs.push([key, value]);

      });

      iterable = iterablePairs;

    }

    if (iterable != null) {

      for (var i = 0; i < iterable.length; i++) {

        this.set(iterable[i][0], iterable[i][1]);

      }

    }

  }

  /**

   * Accessor property returning the number of elements.

   *

   * @return {number} Number of elements.

   */

  _createClass(EquivalentKeyMap, [{

    key: "set",

    /**

     * Add or update an element with a specified key and value.

     *

     * @param {*} key   The key of the element to add.

     * @param {*} value The value of the element to add.

     *

     * @return {EquivalentKeyMap} Map instance.

     */

    value: function set(key, value) {

      // Shortcut non-object-like to set on internal Map.

      if (key === null || _typeof(key) !== 'object') {

        this._map.set(key, value);

        return this;

      } // Sort keys to ensure stable assignment into tree.

      var properties = Object.keys(key).sort();

      var valuePair = [key, value]; // Tree by type to avoid conflicts on numeric object keys, empty value.

      var map = Array.isArray(key) ? this._arrayTreeMap : this._objectTreeMap;

      for (var i = 0; i < properties.length; i++) {

        var property = properties[i];

        if (!map.has(property)) {

          map.set(property, new EquivalentKeyMap());

        }

        map = map.get(property);

        var propertyValue = key[property];

        if (!map.has(propertyValue)) {

          map.set(propertyValue, new EquivalentKeyMap());

        }

        map = map.get(propertyValue);

      } // If an _ekm_value exists, there was already an equivalent key. Before

      // overriding, ensure that the old key reference is removed from map to

      // avoid memory leak of accumulating equivalent keys. This is, in a

      // sense, a poor man's WeakMap, while still enabling iterability.

      var previousValuePair = map.get('_ekm_value');

      if (previousValuePair) {

        this._map.delete(previousValuePair[0]);

      }

      map.set('_ekm_value', valuePair);

      this._map.set(key, valuePair);

      return this;

    }

    /**

     * Returns a specified element.

     *

     * @param {*} key The key of the element to return.

     *

     * @return {?*} The element associated with the specified key or undefined

     *              if the key can't be found.

     */

  }, {

    key: "get",

    value: function get(key) {

      // Shortcut non-object-like to get from internal Map.

      if (key === null || _typeof(key) !== 'object') {

        return this._map.get(key);

      }

      var valuePair = getValuePair(this, key);

      if (valuePair) {

        return valuePair[1];

      }

    }

    /**

     * Returns a boolean indicating whether an element with the specified key

     * exists or not.

     *

     * @param {*} key The key of the element to test for presence.

     *

     * @return {boolean} Whether an element with the specified key exists.

     */

  }, {

    key: "has",

    value: function has(key) {

      if (key === null || _typeof(key) !== 'object') {

        return this._map.has(key);

      } // Test on the _presence_ of the pair, not its value, as even undefined

      // can be a valid member value for a key.

      return getValuePair(this, key) !== undefined;

    }

    /**

     * Removes the specified element.

     *

     * @param {*} key The key of the element to remove.

     *

     * @return {boolean} Returns true if an element existed and has been

     *                   removed, or false if the element does not exist.

     */

  }, {

    key: "delete",

    value: function _delete(key) {

      if (!this.has(key)) {

        return false;

      } // This naive implementation will leave orphaned child trees. A better

      // implementation should traverse and remove orphans.

      this.set(key, undefined);

      return true;

    }

    /**

     * Executes a provided function once per each key/value pair, in insertion

     * order.

     *

     * @param {Function} callback Function to execute for each element.

     * @param {*}        thisArg  Value to use as `this` when executing

     *                            `callback`.

     */

  }, {

    key: "forEach",

    value: function forEach(callback) {

      var _this = this;

      var thisArg = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : this;

      this._map.forEach(function (value, key) {

        // Unwrap value from object-like value pair.

        if (key !== null && _typeof(key) === 'object') {

          value = value[1];

        }

        callback.call(thisArg, value, key, _this);

      });

    }

    /**

     * Removes all elements.

     */

  }, {

    key: "clear",

    value: function clear() {

      this._map = new Map();

      this._arrayTreeMap = new Map();

      this._objectTreeMap = new Map();

    }

  }, {

    key: "size",

    get: function get() {

      return this._map.size;

    }

  }]);

  return EquivalentKeyMap;

}();

module.exports = EquivalentKeyMap;

/***/ }),