Chat private messages (protocol v2)

[Fanfblrik]

Summary

• Chat protocol v2: optional outbound userId on chat messages (null = public broadcast). Public chat unchanged when omitted.
• Server maps websocket sessions to authenticated user ids and delivers private messages only to sender + recipient sessions subscribed to the game. Relayed payload uses private: true (no recipient id/name on the wire). chatVersion is 2 when chat is enabled.
• ChatPopup shows a To: selector (Everyone + other human major civs) when chatVersion >= 2. Private lines render as Sender (private): text. Spectators / Unknown keep Everyone-only.
• ignoreUnknownKeys enabled on client/server chat JSON for forward compatibility.

Test plan

• .\gradlew :core:compileKotlin :server:compileKotlin
• Against a v2 server jar: open chat → recipient list appears; public messages still visible to all
• A → B private: only A and B see it; C does not
• Against chatVersion 1 / 0: no recipient selector; public chat works as before
• Unknown/spectator: no private targets (Everyone only)
• Sender (private) display is clear enough without recipient name in the log

[Fanfblrik]

Merge order: if landing more than one of these chat PRs, please merge in this sequence to avoid conflicts / lost behavior:

1. Chat: nation-colored names, white body #15289 — nation-colored name + white message body
2. Persist multiplayer chat history on this device (opt-in) #15290 — local on-device chat history (opt-in)
3. Chat private messages (protocol v2) #15291 — private messages (chat protocol v2)

Reason: all three touch ChatPopup / ChatStore. #15291 does not include #15289's coloring, and #15290/#15291 disagree on message storage shape (Pair vs ChatMessageEntry / toCivName), so out-of-order merges need a careful rebase.

[Fanfblrik]

Happy to rebase / fix merge conflicts (and any review feedback) — just say the word.

[touhidurrr]

is toCivName really necessary?
For server if userId is provided then the server should send the message to designated userId only.
When a private message is sent, the server can just add private: true to say that this message is only for you. And when personal == true, you can display (private) after civName
A full userId is not necessary.

[touhidurrr]

So, mainly too many unnecessary properties.

[touhidurrr]

Ok @Fanfblrik , I have added your protocol v2 support in UncivServer.xyz. The gist of it is below:

1. To send a private message include userId field to payload
2. If a message is a private message, the server sent message has private: true on, otherwise private maybe omitted or be false.

Kindly test with the server and see if it works.

[touhidurrr]

Also, I think you need to add a 4th pull request or modify this to add UI support for sending private messages.

[Fanfblrik]

I was just doing some testing.

[Fanfblrik]

Addressed review feedback in 3cd1e0a82:

• Outbound: userId for private routing (null = public)
• Inbound: private: true only — no toCivName / recipient id echo
• UI: Sender (private): …; To: selector left-aligned with its label
• Local two-client test: public + private delivery looks good; (private) without recipient name is fine in the log

[touhidurrr]

Addressed review feedback in 3cd1e0a82:

• Outbound: userId for private routing (null = public)
• Inbound: private: true only — no toCivName / recipient id echo
• UI: Sender (private): …; To: selector left-aligned with its label
• Local two-client test: public + private delivery looks good; (private) without recipient name is fine in the log

Does UncivServer.xyz work?