Live replays

Dependencies

Server:

• Centrifugo (docs)

HDT:

• Own centrifugal implementation

Web client:

• centrifuge.js
• sha256.js
• sockjs (for compat?)
• joust

Live replay session

1. HDT connects to Centrifugo and asks to create a new channel. Centrifugo replies with the created channel. (How to do this?)

• Channel can be made public (as in, browsable from the user's page), or accessible only with the URL (shared secret?)

2. HDT user shares URL.
3. Web user goes to URL, enters the channel
4. Gets the beginning of the match up until now from somewhere... - Is the history method enough to do this? Maybe there's too many messages. - It would appear so. history_lifetime needs to be configured.
5. Listens for further messages
6. Forwards everything to Joust

Joust packets

The simplest way to packetize hsreplay is to flush every time a top-level action is closed. This is problematic for Discover... maybe tracking too. Because the choices are blocking and not top-level. But nothing else.

A more complex way is to follow more closely the game's protocol, sending in ACTION_BEGIN and ACTION_END. Maybe flush every second. This would let us send fewer packets while still respecting choice "waits".

We can also, instead of all that, simply implement a minimum wait time on choices in joust, eg. an animation like Hearthstone does. This solves the problem very neatly.

Notes

• Make sure the data can't be harmful to the clients as it will essentially not be changed from HDT to web client
• (Later) presence can be used to tell how many concurrent live viewers are there. Once we have enough...