/* ----------------------------------------------------------------------------
 * Easy!Appointments - Open Source Web Scheduler
 *
 * @package     EasyAppointments
 * @author      A.Tselegidis <alextselegidis@gmail.com>
 * @copyright   Copyright (c) 2013 - 2017, Alex Tselegidis
 * @license     http://opensource.org/licenses/GPL-3.0 - GPLv3
 * @link        http://easyappointments.org
 * @since       v1.2.0
 * ---------------------------------------------------------------------------- */

/**
 * Backend Calendar Google Sync
 *
 * This module implements the Google Calendar sync operations. 
 *
 * @module BackendCalendarGoogleSync
 */
window.BackendCalendarGoogleSync = window.BackendCalendarGoogleSync || {};

(function(exports) {

    'use strict';

    /**
     * Bind event handlers. 
     */
    function _bindEventHandlers() {
        /**
         * Event: Enable - Disable Synchronization Button "Click"
         *
         * When the user clicks on the "Enable Sync" button, a popup should appear
         * that is going to follow the web server authorization flow of OAuth.
         */
        $('#enable-sync').click(function() {
            if ($('#enable-sync').hasClass('enabled') === false) {
                // Enable synchronization for selected provider.
                var authUrl = GlobalVariables.baseUrl + '/index.php/google/oauth/'
                        + $('#select-filter-item').val();

                var redirectUrl = GlobalVariables.baseUrl + '/index.php/google/oauth_callback';

                var windowHandle = window.open(authUrl, 'Authorize Easy!Appointments',
                        'width=800, height=600');

                var authInterval = window.setInterval(function() {
                    // When the browser redirects to the google user consent page the "window.document" variable
                    // becomes "undefined" and when it comes back to the redirect URL it changes back. So check
                    // whether the variable is undefined to avoid javascript errors.
                    try {
                        if (windowHandle.document !== undefined) {
                        if (windowHandle.document.URL.indexOf(redirectUrl) !== -1) {
                            // The user has granted access to his data.
                            windowHandle.close();
                            window.clearInterval(authInterval);
                            $('#enable-sync').addClass('btn-danger enabled');
                            $('#enable-sync span:eq(1)').text(EALang.disable_sync);
                            $('#google-sync').prop('disabled', false);
                            $('#select-filter-item option:selected').attr('google-sync', 'true');

                            // Display the calendar selection dialog. First we will get a list of the available
                            // user's calendars and then we will display a selection modal so the user can select
                            // the sync calendar.
                            var postUrl = GlobalVariables.baseUrl + '/index.php/backend_api/ajax_get_google_calendars';
                            var postData = {
                                csrfToken: GlobalVariables.csrfToken,
                                provider_id: $('#select-filter-item').val()
                            };

                            $.post(postUrl, postData, function(response) {
                                if (!GeneralFunctions.handleAjaxExceptions(response)) {
                                    return;
                                }

                                $('#google-calendar').empty();
                                $.each(response, function() {
                                    var option = '<option value="' + this.id  + '">' + this.summary + '</option>';
                                    $('#google-calendar').append(option);
                                });

                                $('#select-google-calendar').modal('show');
                            }, 'json').fail(GeneralFunctions.ajaxFailureHandler);
                        }
                    }
                    } catch(Error) {
                        // Accessing the document object before the window is loaded throws an error, but
                        // it will only happen during the initialization of the window. Attaching "load"
                        // event handling is not possible due to CORS restrictions.
                    }
                }, 100);

            } else {
                // Disable synchronization for selected provider.
                // Update page elements and make an AJAX call to remove the google sync setting of the
                // selected provider.
                $.each(GlobalVariables.availableProviders, function(index, provider) {
                    if (provider.id == $('#select-filter-item').val()) {
                        provider.settings.google_sync = '0';
                        provider.settings.google_token = null;

                        _disableProviderSync(provider.id);

                        $('#enable-sync').removeClass('btn-danger enabled');
                        $('#enable-sync span:eq(1)').text(EALang.enable_sync);
                        $('#google-sync').prop('disabled', true);
                        $('#select-filter-item option:selected').attr('google-sync', 'false');

                        return false;
                    }
                });
            }
        });

        /**
         * Event: Select Google Calendar "Click"
         */
        $('#select-calendar').click(function() {
            var postUrl = GlobalVariables.baseUrl + '/index.php/backend_api/ajax_select_google_calendar';
            var postData = {
                csrfToken: GlobalVariables.csrfToken,
                provider_id: $('#select-filter-item').val(),
                calendar_id: $('#google-calendar').val()
            };
            $.post(postUrl, postData, function(response) {
                if (!GeneralFunctions.handleAjaxExceptions(response)) {
                    return;
                }
                Backend.displayNotification(EALang.google_calendar_selected);
                $('#select-google-calendar').modal('hide');
            }, 'json').fail(GeneralFunctions.ajaxFailureHandler);
        });

        /**
         * Event: Close Google Calendar "Click"
         */
        $('#close-calendar').click(function() {
            $('#select-google-calendar').modal('hide');
        });

        /**
         * Event: Google Sync Button "Click"
         *
         * Trigger the synchronization algorithm.
         */
        $('#google-sync').click(function() {
            var url = GlobalVariables.baseUrl + '/index.php/google/sync/' + $('#select-filter-item').val();

            $.ajax({
                url: url,
                type: 'GET',
                dataType: 'json'
            })
                .done(function(response) {
                    if (response.exceptions) {
                        response.exceptions = GeneralFunctions.parseExceptions(response.exceptions);
                        GeneralFunctions.displayMessageBox(GeneralFunctions.EXCEPTIONS_TITLE,
                                GeneralFunctions.EXCEPTIONS_MESSAGE);
                        $('#message_box').append(GeneralFunctions.exceptionsToHtml(response.exceptions));
                        return;
                    }

                    if (response.warnings) {
                        response.warnings = GeneralFunctions.parseExceptions(response.warnings);
                        GeneralFunctions.displayMessageBox(GeneralFunctions.WARNINGS_TITLE,
                                GeneralFunctions.WARNINGS_MESSAGE);
                        $('#message_box').append(GeneralFunctions.exceptionsToHtml(response.warnings));
                    }

                    Backend.displayNotification(EALang.google_sync_completed);
                    $('#reload-appointments').trigger('click');
                })
                .fail(function(jqXHR, textStatus, errorThrown) {
                    Backend.displayNotification(EALang.google_sync_failed);
                });
        });
    }

    /**
     * Disable Provider Sync
     *
     * This method disables the google synchronization for a specific provider.
     *
     * @param {Number} providerId The selected provider record ID.
     */
    function _disableProviderSync(providerId) {
        // Make an ajax call to the server in order to disable the setting
        // from the database.
        var postUrl = GlobalVariables.baseUrl + '/index.php/backend_api/ajax_disable_provider_sync';
        var postData = {
            csrfToken: GlobalVariables.csrfToken,
            provider_id: providerId
        };

        $.post(postUrl, postData, function(response) {
            if (response.exceptions) {
                response.exceptions = GeneralFunctions.parseExceptions(response.exceptions);
                GeneralFunctions.displayMessageBox(GeneralFunctions.EXCEPTIONS_TITLE, GeneralFunctions.EXCEPTIONS_MESSAGE);
                $('#message_box').append(GeneralFunctions.exceptionsToHtml(response.exceptions));
            }
        }, 'json').fail(GeneralFunctions.ajaxFailureHandler);
    }


    exports.initialize = function() {
        _bindEventHandlers(); 
    };

})(window.BackendCalendarGoogleSync);