events_initialization.js

var Bluebird = require("bluebird");
var GoogleCalendarQueue = require.main.require("./workers/lib/queue")("google_calendar_queue");
var Thinky = require("../../thinky");
var GoogleCalendarEventUpsertion = require("../../google/calendar/event_upsertion");
var Log = require("./log").namespace({ operation: "events_initialization" });

function GoogleCalendarEventsInitialization(googleCalendarId) {

    var googleCalendarEvent;

    function getNextUninitializedGoogleCalendarEvent() {
        return Thinky.r.table("google_calendar_events")
            .getAll(
                [ googleCalendarId, "uninitialized" ],
                { index: "googleCalendarId|status" }
            )
            .limit(1)
            .update(
                { status: "initializing" },
                { returnChanges: true }
            )
            .then(function (result) {
                if (result.replaced === 1) {
                    googleCalendarEvent = result.changes[0].new_val;
                    return googleCalendarEvent;
                }

                if (result.replaced === 0) {
                    googleCalendarEvent = null;
                    return googleCalendarEvent;
                }

                Log.log({
                    event: "getting_next_uninitialized_google_calendar_event",
                    googleCalendarId: googleCalendarId
                });
                Log.log(result);
                throw new Error(
                    "Expected to replace zero or one documents. Replaced " +
                    result.replaced +
                    " instead."
                );
            });
    }

    function upsertGoogleCalendarEvent() {
        Log.log({
            event: "upserting",
            googleCalendarId: googleCalendarEvent.googleCalendarId,
            bookingId: googleCalendarEvent.bookingId
        });
        return GoogleCalendarEventUpsertion(
            googleCalendarEvent.googleCalendarId,
            googleCalendarEvent.bookingId,
            "initialized"
        );
    }

    function queueNextEventsInitialization() {
        return GoogleCalendarQueue.add({
            operation: "initialize_events",
            googleCalendarId: googleCalendarId
        });
    }

    function logAndQueueNextEventsInitialization(err) {
        Log.log({
            event: "failed",
            googleCalendarId: googleCalendarEvent.googleCalendarId,
            bookingId: googleCalendarEvent.bookingId
        });
        Log.error(err);
        return queueNextEventsInitialization();
    }

    function initializeGoogleCalendarEvent() {
        if (googleCalendarEvent) {
            return upsertGoogleCalendarEvent()
                .then(queueNextEventsInitialization)
                .catch(logAndQueueNextEventsInitialization);
        }

        return Bluebird.resolve();
    }

    return getNextUninitializedGoogleCalendarEvent()
        .then(initializeGoogleCalendarEvent);
}

module.exports = GoogleCalendarEventsInitialization;