Support Ready State + Start Count Down

[timotheeg]

What's needed:

• Players can click on a button in their producer page to state they are ready, ready state propagates to views and admin page (this is new, normally producer pages do not send commands)
• Views shows a ready state for the players who are ready (new type of curtain overlay, like the curtain and the profile page)
• Admin has a Start Count Down button of some sort, which when clicked, shows the countdown in the views, 5s will do, as specified by Kingsman here
• When count down hits 0, curtain overlay disappears, and gameplay shows as per normal
• Count down should be communicated to players visually (and with Text to speech?) in their producer page in real time to facilitate a synchronous start amongst players (same behaviour as the twitch count down bot)

Bonus:

• producer page can show a simplified view of the entire game room for all players, so players can see each other's game in real time, which is better than relying on the (much delayed) twitch stream -> possibly hard to support all the view and room types...

To decide:

• If over-enthusiastic players starts game before countdown is over, do we:
  1. immediately show the gameplay? (i.e. hide the count down overlay immediately)
  2. keep the count down curtain up and only hide it to reveal the game in progress when reaching 0 -> artificial sync of all players
  3. (not recommended) buffer play frames from all players to actually make the game start at the same time (not real time any more, introduces delay between camera and gameplay)
• Should the setReady call be remembered on the server, or only be a view property?
  • view property means that when the view receives the signal it, shows what it needs to show, but if the view needs to be refreshed, the player would have to click "ready" again, because neither the fresh view nor the server would know/remember that the player is ready (easier but more fragile)
  • storing data on server is more resilient, but now we must handle synchrony between view and server.

Note: This is somewhat related to the Round PR, where the admin can specify a start and end of a "round", and information from the games recorded during the round can then be retrieved from the DB (e.g. average scores, max score, num maxouts, etc.)

[timotheeg]

Done with PR https://github.com/timotheeg/nestrischamps/pull/164

Somenotes:

• count down stops as soon as player starts his/her game
• 0 is not shown, the counter disappears as we wait for the player game to start
• Admin can remove the comp messages if needed
• The ready state and count down states are not stored on the server (for now?)