'use strict';

Object.defineProperty(exports, '__esModule', {
  value: true
});

var _createClass = (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); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; })();

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError('Cannot call a class as a function'); } }

var MiniSignalBinding = (function () {
  function MiniSignalBinding(fn, once, thisArg) {
    if (once === undefined) once = false;

    _classCallCheck(this, MiniSignalBinding);

    this._fn = fn;
    this._once = once;
    this._thisArg = thisArg;
    this._next = this._prev = this._owner = null;
  }

  _createClass(MiniSignalBinding, [{
    key: 'detach',
    value: function detach() {
      if (this._owner === null) return false;
      this._owner.detach(this);
      return true;
    }
  }]);

  return MiniSignalBinding;
})();

function _addMiniSignalBinding(self, node) {
  if (!self._head) {
    self._head = node;
    self._tail = node;
  } else {
    self._tail._next = node;
    node._prev = self._tail;
    self._tail = node;
  }

  node._owner = self;

  return node;
}

var MiniSignal = (function () {
  function MiniSignal() {
    _classCallCheck(this, MiniSignal);

    this._head = this._tail = undefined;
  }

  _createClass(MiniSignal, [{
    key: 'handlers',
    value: function handlers() {
      var exists = arguments.length <= 0 || arguments[0] === undefined ? false : arguments[0];

      var node = this._head;

      if (exists) return !!node;

      var ee = [];

      while (node) {
        ee.push(node);
        node = node._next;
      }

      return ee;
    }
  }, {
    key: 'has',
    value: function has(node) {
      if (!(node instanceof MiniSignalBinding)) {
        throw new Error('MiniSignal#has(): First arg must be a MiniSignalBinding object.');
      }

      return node._owner === this;
    }
  }, {
    key: 'dispatch',
    value: function dispatch() {
      var node = this._head;

      if (!node) return false;

      while (node) {
        if (node._once) this.detach(node);
        node._fn.apply(node._thisArg, arguments);
        node = node._next;
      }

      return true;
    }
  }, {
    key: 'add',
    value: function add(fn) {
      var thisArg = arguments.length <= 1 || arguments[1] === undefined ? null : arguments[1];

      if (typeof fn !== 'function') {
        throw new Error('MiniSignal#add(): First arg must be a Function.');
      }
      return _addMiniSignalBinding(this, new MiniSignalBinding(fn, false, thisArg));
    }
  }, {
    key: 'once',
    value: function once(fn) {
      var thisArg = arguments.length <= 1 || arguments[1] === undefined ? null : arguments[1];

      if (typeof fn !== 'function') {
        throw new Error('MiniSignal#once(): First arg must be a Function.');
      }
      return _addMiniSignalBinding(this, new MiniSignalBinding(fn, true, thisArg));
    }
  }, {
    key: 'detach',
    value: function detach(node) {
      if (!(node instanceof MiniSignalBinding)) {
        throw new Error('MiniSignal#detach(): First arg must be a MiniSignalBinding object.');
      }
      if (node._owner !== this) return this;

      if (node._prev) node._prev._next = node._next;
      if (node._next) node._next._prev = node._prev;

      if (node === this._head) {
        this._head = node._next;
        if (node._next === null) {
          this._tail = null;
        }
      } else if (node === this._tail) {
        this._tail = node._prev;
        this._tail._next = null;
      }

      node._owner = null;
      return this;
    }
  }, {
    key: 'detachAll',
    value: function detachAll() {
      var node = this._head;
      if (!node) return this;

      this._head = this._tail = null;

      while (node) {
        node._owner = null;
        node = node._next;
      }
      return this;
    }
  }]);

  return MiniSignal;
})();

MiniSignal.MiniSignalBinding = MiniSignalBinding;

exports['default'] = MiniSignal;
module.exports = exports['default'];