feat(plugins): add c2.WebSocket

[Nerixyz]

Adds a small WebSocket client. Connections must use TLS.

Example

Go in a Twitch channel and run /mirror-chat. All chat messages will now appear twice.

---@type c2.WebSocket|nil
local ws = nil
c2.register_command("/mirror-chat", function(ctx)
    if ws then
        ws:close()
    end
    local proto = "wss"
    if #ctx.words >= 2 then
        proto = ctx.words[2]
    end
    ws = c2.WebSocket.new(proto .. "://irc-ws.chat.twitch.tv")
    local chan = ctx.channel
    ws.on_text = function(text)
        -- Don't care about multiple messages in one
        text = text:sub(1, -3)
        if #text > 4 and text:sub(1, 4) == 'PING' then
            ws:send_text("PONG" .. text:sub(5))
            return
        end

        local sender_end = text:find(' ', 1, true)
        if sender_end == nil then
            return
        end
        local sender = text:sub(2, sender_end - 1)

        local command_end = text:find(' ', sender_end + 1, true)
        if command_end == nil then
            return
        end
        local command = text:sub(sender_end + 1, command_end - 1)
        if command ~= "PRIVMSG" then
            return
        end

        local name_end = sender:find('!', 1, true)
        if name_end == nil then
            return
        end
        local sender_name = sender:sub(1, name_end - 1)

        local msg_start = text:find(':', command_end + 1, true)
        if msg_start == nil then
            return
        end
        chan:add_system_message(sender_name .. ": " .. text:sub(msg_start + 1))
    end
    ws:send_text("NICK justinfan123456")
    ws:send_text("JOIN #" .. ctx.channel:get_name())
    chan:add_system_message("Mirroring messages")
end)

Requests: #4931, #4999 (comment)

[Mm2PL]

How did you decide on the TLS requirement? It seems weird to not be able to connect to another local program.

[Nerixyz]

How did you decide on the TLS requirement? It seems weird to not be able to connect to another local program.

Because of Boost.Beast and that you need to statically declare the types of streams. It's not super hard to add non-TLS streams. I could do it later.

[github-actions]

clang-tidy made some suggestions

There were too many comments to post at once. Showing the first 25 out of 27. Check the log or trigger a new build to see more.

[Nerixyz]

I could do it later.

Added.

[Nerixyz]

This is because of https://redirect.github.com/ThePhD/sol2/issues/1581. Builds with Clang 18 fail. 17 and 19 both work.

[Nerixyz]

If I understand the docs correctly, then we have to use namespace here instead of module.

[Nerixyz]

This is currently scoped to the controller but could technically be global to the app.

[Nerixyz]

fromRawData creates a view over the data (it doesn't copy) and is suspect to dangling references. We should use QByteArrayView for this.

[Nerixyz]

This now accepts non-copyable functions (e.g. lambdas with std::unique_ptr captures).