/**
   * Copyright (c) 2014, Arthur Schiwon <blizzz@owncloud.com>
   * This file is licensed under the Affero General Public License version 3 or later.
   * See the COPYING-README file.
   */
  
  /**
   * takes care of deleting things represented by an ID
   *
   * @class
   * @param {string} endpoint the corresponding ajax PHP script. Currently limited
   * to settings - ajax path.
   * @param {string} paramID the by the script expected parameter name holding the
   * ID of the object to delete
   * @param {markCallback} markCallback function to be called after successfully
   * marking the object for deletion.
   * @param {removeCallback} removeCallback the function to be called after
   * successful delete.
   */
  function DeleteHandler(endpoint, paramID, markCallback, removeCallback) {
  	this.oidToDelete = false;
  	this.canceled = false;
  
  	this.ajaxEndpoint = endpoint;
  	this.ajaxParamID = paramID;
  
  	this.markCallback = markCallback;
  	this.removeCallback = removeCallback;
  	this.undoCallback = false;
  
  	this.notifier = false;
  	this.notificationDataID = false;
  	this.notificationMessage = false;
  	this.notificationPlaceholder = '%oid';
  }
  
  /**
   * The function to be called after successfully marking the object for deletion
   * @callback markCallback
   * @param {string} oid the ID of the specific user or group
   */
  
  /**
   * The function to be called after successful delete. The id of the object will
   * be passed as argument. Unsuccessful operations will display an error using
   * OC.dialogs, no callback is fired.
   * @callback removeCallback
   * @param {string} oid the ID of the specific user or group
   */
  
  /**
   * This callback is fired after "undo" was clicked so the consumer can update
   * the web interface
   * @callback undoCallback
   * @param {string} oid the ID of the specific user or group
   */
  
  /**
   * enabled the notification system. Required for undo UI.
   *
   * @param {object} notifier Usually OC.Notification
   * @param {string} dataID an identifier for the notifier, e.g. 'deleteuser'
   * @param {string} message the message that should be shown upon delete. %oid
   * will be replaced with the affected id of the item to be deleted
   * @param {undoCallback} undoCallback called after "undo" was clicked
   */
  DeleteHandler.prototype.setNotification = function(notifier, dataID, message, undoCallback) {
  	this.notifier = notifier;
  	this.notificationDataID = dataID;
  	this.notificationMessage = message;
  	this.undoCallback = undoCallback;
  
  	var dh = this;
  
  	$('#notification').on('click', '.undo', function () {
  		if ($('#notification').data(dh.notificationDataID)) {
  			var oid = dh.oidToDelete;
  			dh.cancel();
  			if(typeof dh.undoCallback !== 'undefined') {
  				dh.undoCallback(oid);
  			}
  		}
  		dh.notifier.hide();
  	});
  };
  
  /**
   * shows the Undo Notification (if configured)
   */
  DeleteHandler.prototype.showNotification = function() {
  	if(this.notifier !== false) {
  		if(!this.notifier.isHidden()) {
  			this.hideNotification();
  		}
  		$('#notification').data(this.notificationDataID, true);
  		var msg = this.notificationMessage.replace(
  			this.notificationPlaceholder, escapeHTML(this.oidToDelete));
  		this.notifier.showHtml(msg);
  	}
  };
  
  /**
   * hides the Undo Notification
   */
  DeleteHandler.prototype.hideNotification = function() {
  	if(this.notifier !== false) {
  		$('#notification').removeData(this.notificationDataID);
  		this.notifier.hide();
  	}
  };
  
  /**
   * initializes the delete operation for a given object id
   *
   * @param {string} oid the object id
   */
  DeleteHandler.prototype.mark = function(oid) {
  	if(this.oidToDelete !== false) {
  		this.deleteEntry();
  	}
  	this.oidToDelete = oid;
  	this.canceled = false;
  	this.markCallback(oid);
  	this.showNotification();
  };
  
  /**
   * cancels a delete operation
   */
  DeleteHandler.prototype.cancel = function() {
  	this.canceled = true;
  	this.oidToDelete = false;
  };
  
  /**
   * executes a delete operation. Requires that the operation has been
   * initialized by mark(). On error, it will show a message via
   * OC.dialogs.alert. On success, a callback is fired so that the client can
   * update the web interface accordingly.
   */
  DeleteHandler.prototype.deleteEntry = function() {
  	if(this.canceled || this.oidToDelete === false) {
  		return false;
  	}
  
  	var dh = this;
  	if($('#notification').data(this.notificationDataID) === true) {
  		dh.hideNotification();
  	}
  
  	var payload = {};
  	payload[dh.ajaxParamID] = dh.oidToDelete;
  	$.ajax({
  		type: 'POST',
  		url: OC.filePath('settings', 'ajax', dh.ajaxEndpoint),
  		async: false,
  		data: payload,
  		success: function (result) {
  			if (result.status === 'success') {
  				// Remove undo option, & remove user from table
  
  				//TODO: following line
  				dh.removeCallback(dh.oidToDelete);
  				dh.canceled = true;
  			} else {
  				OC.dialogs.alert(result.data.message, t('settings', 'Unable to delete {objName}', {objName: escapeHTML(dh.oidToDelete)}));
  				dh.undoCallback(dh.oidToDelete);
  			}
  		}
  	});
  };