Syncs leaves from Alibeez to Google Calendar.

The program needs permission from users to write to their calendars. Therefore, the work of the program is divided into two phases: an initialization flow where the program collects the permission of a user, and an update flow where leaves for all users are sync'ed up.

• User hits / with their browser, where they are invited to give permission to the program to make changes to their calendars.
• If the user proceeds, the program completes the OAuth 2 dance and acquires some user information, including the necessary tokens to call the Calendar API.
• The program pulls the active future leaves of the user from Alibeez and copies them over to Calendar.

• At regular intervals, the program pulls all leaves that have been updated since the previous update flow.
• For leaves for which the user has given permission (i.e. tokens are known) the program either adds it to Calendar or removes it from Calendar, depending on its status.

• Copy .env.example to .env then fill out .env with the required values. You may ask [email protected] for working values.
• Run npm install to install dependencies.
• Run npm start to run the app.

This program persists data using JSON files. Since files already exist in production, new versions of the program must be backward compatible with the format and schema of those files, unless there is a possibility and will to notify all users that they are required to go through the initialization flow again (which would persist new files).