'use strict';

exports.__esModule = true;
exports.fixEvent = fixEvent;
exports.on = on;
exports.off = off;
exports.trigger = trigger;
exports.one = one;

var _dom = require('./dom.js');

var Dom = _interopRequireWildcard(_dom);

var _guid = require('./guid.js');

var Guid = _interopRequireWildcard(_guid);

var _window = require('global/window');

var _window2 = _interopRequireDefault(_window);

var _document = require('global/document');

var _document2 = _interopRequireDefault(_document);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { 'default': obj }; }

function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj['default'] = obj; return newObj; } }

/**
 * Clean up the listener cache and dispatchers
*
 * @param  {Element|Object} elem Element to clean up
 * @param  {String} type Type of event to clean up
 * @private
 * @method _cleanUpEvents
 */
/**
 * @file events.js
 *
 * Event System (John Resig - Secrets of a JS Ninja http://jsninja.com/)
 * (Original book version wasn't completely usable, so fixed some things and made Closure Compiler compatible)
 * This should work very similarly to jQuery's events, however it's based off the book version which isn't as
 * robust as jquery's, so there's probably some differences.
 */

function _cleanUpEvents(elem, type) {
  var data = Dom.getElData(elem);

  // Remove the events of a particular type if there are none left
  if (data.handlers[type].length === 0) {
    delete data.handlers[type];
    // data.handlers[type] = null;
    // Setting to null was causing an error with data.handlers

    // Remove the meta-handler from the element
    if (elem.removeEventListener) {
      elem.removeEventListener(type, data.dispatcher, false);
    } else if (elem.detachEvent) {
      elem.detachEvent('on' + type, data.dispatcher);
    }
  }

  // Remove the events object if there are no types left
  if (Object.getOwnPropertyNames(data.handlers).length <= 0) {
    delete data.handlers;
    delete data.dispatcher;
    delete data.disabled;
  }

  // Finally remove the element data if there is no data left
  if (Object.getOwnPropertyNames(data).length === 0) {
    Dom.removeElData(elem);
  }
}

/**
 * Loops through an array of event types and calls the requested method for each type.
 *
 * @param  {Function} fn   The event method we want to use.
 * @param  {Element|Object} elem Element or object to bind listeners to
 * @param  {String}   type Type of event to bind to.
 * @param  {Function} callback   Event listener.
 * @private
 * @function _handleMultipleEvents
 */
function _handleMultipleEvents(fn, elem, types, callback) {
  types.forEach(function (type) {
    // Call the event method for each one of the types
    fn(elem, type, callback);
  });
}

/**
 * Fix a native event to have standard property values
 *
 * @param  {Object} event Event object to fix
 * @return {Object}
 * @private
 * @method fixEvent
 */
function fixEvent(event) {

  function returnTrue() {
    return true;
  }

  function returnFalse() {
    return false;
  }

  // Test if fixing up is needed
  // Used to check if !event.stopPropagation instead of isPropagationStopped
  // But native events return true for stopPropagation, but don't have
  // other expected methods like isPropagationStopped. Seems to be a problem
  // with the Javascript Ninja code. So we're just overriding all events now.
  if (!event || !event.isPropagationStopped) {
    (function () {
      var old = event || _window2['default'].event;

      event = {};
      // Clone the old object so that we can modify the values event = {};
      // IE8 Doesn't like when you mess with native event properties
      // Firefox returns false for event.hasOwnProperty('type') and other props
      //  which makes copying more difficult.
      // TODO: Probably best to create a whitelist of event props
      for (var key in old) {
        // Safari 6.0.3 warns you if you try to copy deprecated layerX/Y
        // Chrome warns you if you try to copy deprecated keyboardEvent.keyLocation
        // and webkitMovementX/Y
        if (key !== 'layerX' && key !== 'layerY' && key !== 'keyLocation' && key !== 'webkitMovementX' && key !== 'webkitMovementY') {
          // Chrome 32+ warns if you try to copy deprecated returnValue, but
          // we still want to if preventDefault isn't supported (IE8).
          if (!(key === 'returnValue' && old.preventDefault)) {
            event[key] = old[key];
          }
        }
      }

      // The event occurred on this element
      if (!event.target) {
        event.target = event.srcElement || _document2['default'];
      }

      // Handle which other element the event is related to
      if (!event.relatedTarget) {
        event.relatedTarget = event.fromElement === event.target ? event.toElement : event.fromElement;
      }

      // Stop the default browser action
      event.preventDefault = function () {
        if (old.preventDefault) {
          old.preventDefault();
        }
        event.returnValue = false;
        old.returnValue = false;
        event.defaultPrevented = true;
      };

      event.defaultPrevented = false;

      // Stop the event from bubbling
      event.stopPropagation = function () {
        if (old.stopPropagation) {
          old.stopPropagation();
        }
        event.cancelBubble = true;
        old.cancelBubble = true;
        event.isPropagationStopped = returnTrue;
      };

      event.isPropagationStopped = returnFalse;

      // Stop the event from bubbling and executing other handlers
      event.stopImmediatePropagation = function () {
        if (old.stopImmediatePropagation) {
          old.stopImmediatePropagation();
        }
        event.isImmediatePropagationStopped = returnTrue;
        event.stopPropagation();
      };

      event.isImmediatePropagationStopped = returnFalse;

      // Handle mouse position
      if (event.clientX !== null && event.clientX !== undefined) {
        var doc = _document2['default'].documentElement;
        var body = _document2['default'].body;

        event.pageX = event.clientX + (doc && doc.scrollLeft || body && body.scrollLeft || 0) - (doc && doc.clientLeft || body && body.clientLeft || 0);
        event.pageY = event.clientY + (doc && doc.scrollTop || body && body.scrollTop || 0) - (doc && doc.clientTop || body && body.clientTop || 0);
      }

      // Handle key presses
      event.which = event.charCode || event.keyCode;

      // Fix button for mouse clicks:
      // 0 == left; 1 == middle; 2 == right
      if (event.button !== null && event.button !== undefined) {

        // The following is disabled because it does not pass videojs-standard
        // and... yikes.
        /* eslint-disable */
        event.button = event.button & 1 ? 0 : event.button & 4 ? 1 : event.button & 2 ? 2 : 0;
        /* eslint-enable */
      }
    })();
  }

  // Returns fixed-up instance
  return event;
}

/**
 * Add an event listener to element
 * It stores the handler function in a separate cache object
 * and adds a generic handler to the element's event,
 * along with a unique id (guid) to the element.
 *
 * @param  {Element|Object}   elem Element or object to bind listeners to
 * @param  {String|Array}   type Type of event to bind to.
 * @param  {Function} fn   Event listener.
 * @method on
 */
function on(elem, type, fn) {
  if (Array.isArray(type)) {
    return _handleMultipleEvents(on, elem, type, fn);
  }

  var data = Dom.getElData(elem);

  // We need a place to store all our handler data
  if (!data.handlers) {
    data.handlers = {};
  }

  if (!data.handlers[type]) {
    data.handlers[type] = [];
  }

  if (!fn.guid) {
    fn.guid = Guid.newGUID();
  }

  data.handlers[type].push(fn);

  if (!data.dispatcher) {
    data.disabled = false;

    data.dispatcher = function (event, hash) {

      if (data.disabled) {
        return;
      }

      event = fixEvent(event);

      var handlers = data.handlers[event.type];

      if (handlers) {
        // Copy handlers so if handlers are added/removed during the process it doesn't throw everything off.
        var handlersCopy = handlers.slice(0);

        for (var m = 0, n = handlersCopy.length; m < n; m++) {
          if (event.isImmediatePropagationStopped()) {
            break;
          } else {
            handlersCopy[m].call(elem, event, hash);
          }
        }
      }
    };
  }

  if (data.handlers[type].length === 1) {
    if (elem.addEventListener) {
      elem.addEventListener(type, data.dispatcher, false);
    } else if (elem.attachEvent) {
      elem.attachEvent('on' + type, data.dispatcher);
    }
  }
}

/**
 * Removes event listeners from an element
 *
 * @param  {Element|Object}   elem Object to remove listeners from
 * @param  {String|Array=}   type Type of listener to remove. Don't include to remove all events from element.
 * @param  {Function} fn   Specific listener to remove. Don't include to remove listeners for an event type.
 * @method off
 */
function off(elem, type, fn) {
  // Don't want to add a cache object through getElData if not needed
  if (!Dom.hasElData(elem)) {
    return;
  }

  var data = Dom.getElData(elem);

  // If no events exist, nothing to unbind
  if (!data.handlers) {
    return;
  }

  if (Array.isArray(type)) {
    return _handleMultipleEvents(off, elem, type, fn);
  }

  // Utility function
  var removeType = function removeType(t) {
    data.handlers[t] = [];
    _cleanUpEvents(elem, t);
  };

  // Are we removing all bound events?
  if (!type) {
    for (var t in data.handlers) {
      removeType(t);
    }
    return;
  }

  var handlers = data.handlers[type];

  // If no handlers exist, nothing to unbind
  if (!handlers) {
    return;
  }

  // If no listener was provided, remove all listeners for type
  if (!fn) {
    removeType(type);
    return;
  }

  // We're only removing a single handler
  if (fn.guid) {
    for (var n = 0; n < handlers.length; n++) {
      if (handlers[n].guid === fn.guid) {
        handlers.splice(n--, 1);
      }
    }
  }

  _cleanUpEvents(elem, type);
}

/**
 * Trigger an event for an element
 *
 * @param  {Element|Object}      elem  Element to trigger an event on
 * @param  {Event|Object|String} event A string (the type) or an event object with a type attribute
 * @param  {Object} [hash] data hash to pass along with the event
 * @return {Boolean=} Returned only if default was prevented
 * @method trigger
 */
function trigger(elem, event, hash) {
  // Fetches element data and a reference to the parent (for bubbling).
  // Don't want to add a data object to cache for every parent,
  // so checking hasElData first.
  var elemData = Dom.hasElData(elem) ? Dom.getElData(elem) : {};
  var parent = elem.parentNode || elem.ownerDocument;
  // type = event.type || event,
  // handler;

  // If an event name was passed as a string, creates an event out of it
  if (typeof event === 'string') {
    event = { type: event, target: elem };
  }
  // Normalizes the event properties.
  event = fixEvent(event);

  // If the passed element has a dispatcher, executes the established handlers.
  if (elemData.dispatcher) {
    elemData.dispatcher.call(elem, event, hash);
  }

  // Unless explicitly stopped or the event does not bubble (e.g. media events)
  // recursively calls this function to bubble the event up the DOM.
  if (parent && !event.isPropagationStopped() && event.bubbles === true) {
    trigger.call(null, parent, event, hash);

    // If at the top of the DOM, triggers the default action unless disabled.
  } else if (!parent && !event.defaultPrevented) {
    var targetData = Dom.getElData(event.target);

    // Checks if the target has a default action for this event.
    if (event.target[event.type]) {
      // Temporarily disables event dispatching on the target as we have already executed the handler.
      targetData.disabled = true;
      // Executes the default action.
      if (typeof event.target[event.type] === 'function') {
        event.target[event.type]();
      }
      // Re-enables event dispatching.
      targetData.disabled = false;
    }
  }

  // Inform the triggerer if the default was prevented by returning false
  return !event.defaultPrevented;
}

/**
 * Trigger a listener only once for an event
 *
 * @param  {Element|Object}   elem Element or object to
 * @param  {String|Array}   type Name/type of event
 * @param  {Function} fn Event handler function
 * @method one
 */
function one(elem, type, fn) {
  if (Array.isArray(type)) {
    return _handleMultipleEvents(one, elem, type, fn);
  }
  var func = function func() {
    off(elem, type, func);
    fn.apply(this, arguments);
  };

  // copy the guid to the new function so it can removed using the original function's ID
  func.guid = fn.guid = fn.guid || Guid.newGUID();
  on(elem, type, func);
}
