This is the All-Ireland Mahjong mobile app. This provides live information about tournaments.

For tournament participants, it gives live info during tournament: current scores, which table a given player is on next and when the round starts, etc

Push notifications will let players know when the latest scores are available, and these scores will appear in the app. Players will also receive notifications if the timing or seating plans change, as soon as they change. An app user can choose to get information about any one specific player, and the expectation is that a player will choose to get information about themselves (but there are no constraints on this). If they do, then they'll receive tailored information about which table they are on next, and who they'll be playing with. And they'll get tailored notifications if that information changes.

A tournament admin is able to do everything through a web interface. I envisage them using 3 browser tabs:

• the admin interface
• the google scoring sheet; and
• the live web page; and

The client-side written in Dart with the Flutter framework. It's developed and tested for android, in Android Studio, and for iPhone & iPad(Mini) on xCode.

The server-side is written in Python, with the Flask framework. I'm running it on the server with wsgi. Note that the oauth2 authentication won't work on localhost: you need a google project that knows about the domain that the app is being served from, and must be given the post-authentication URL to redirect back to. GSPRead is used to read the scoresheet, to create the live score web page, and to put the data into the cloud, for onward transmission to the app

App notifications are by Firebase Cloud Messaging. And via APN, for IOS (not tested yet). Live tournament data is stored in Google Cloud Firestore.

When the app has a connection, and is in foreground or background, any update to the firebase cloud data gets noticed by the listener. If the app is closed, then it won't know anything about it, so the server sends FCM notificaions to all subscribed devices.

The live scoring of a tournament is done in a Google spreadsheet, based on the one developed by David Bresnick for the World Riichi Championship.

Thanks to fantastic work by @North101, all of the state is now managed by Riverpod providers & listeners

I've had a few trial run-ups at it, and after a few false starts, have settled on google firebase & cloud messaging because it will be free for the level of use I'm anticipating, and because it takes care of loads of messy stuff such as background syncing of data between mobiles and server, and caching stuff on mobile so that everything behaves just perfectly even when the mobile has patchy signal. I did try crafting my own local caching thing for android, and it was super messy, so it just made sense to let google do all the clever io stuff, and I just concentrate on the mahjong stuff.

In the Google scoresheet, scores are stored in their real form, as floats with one decimal place: so +29.1 is stored as 29.1 And -5.0 is stored as -5.0.

On the server, in the cloud firestore, and in the app, scores are multiplied by 10 and stored as integers. That's to avoid any nonsense with inaccurate floating point arithmetic. So a tournament score of +29.1 is stored as 291. A score of -5.0 is stored as -50. Scores are expected to be received from the server in this form too.

The only place where the conversion is done back to decimal, in the app, is at the final point of display. This happens in lib/score_cell.dart and server/run/run.py

All info is public. This bypasses any issues around privacy policies, age requirements, etc.

There are logins for tournament admin and server admin on the web, using Google oauth2 and Flask logins.

And the Google Sheet that is used for scoring for any given tournament, has access permissions managed by Google.

That score sheet is not public: the only accounts that can see it, will be the tournament scorers. We don't release the scores for a round, until all games in that round have finished. This is important. It removes an incentive to bad behaviour among players.