feat: in-house queue system

* feat: in-house queue system

* refactor(server/queue): organize code

---------

Co-authored-by: Manason <[email protected]>

locale/en.lua

@@ -19,7 +19,8 @@ local Translations = {
         tp_error = 'Error While Teleporting.',
         connecting_database_timeout = 'Connection to database timed out. (Is the SQL server on?)',
         connecting_error = 'An error occurred while connecting to the server. (Check your server console)',
-        no_match_character_registration = 'Anything other than letters aren\'t allowed, trailing whitespaces aren\'t allowed either and words must start with a capital letter in input fields. You can however add words with spaces inbetween.'
+        no_match_character_registration = 'Anything other than letters aren\'t allowed, trailing whitespaces aren\'t allowed either and words must start with a capital letter in input fields. You can however add words with spaces inbetween.',
+        already_in_queue = 'You are already in queue.',
     },
     success = {
         server_opened = 'The server has been opened',
@@ -58,7 +59,8 @@ local Translations = {
         gender = 'Sex',
         birth_date = 'Birth Date',
         select_gender = 'Select your gender...',
-        confirm_delete = 'Are you sure you wish to delete this character?'
+        confirm_delete = 'Are you sure you wish to delete this character?',
+        in_queue = '🐌 You are %{queuePos}/%{queueSize} in queue.',
     },
     command = {
         tp = {

server/events.lua

@@ -1,6 +1,7 @@
 local serverConfig = require 'config.server'.server
 local loggingConfig = require 'config.server'.logging
 local logger = require 'modules.logger'
+local queue = require 'server.queue'
 
 -- Event Handler
 
@@ -108,7 +109,11 @@ local function onPlayerConnecting(name, _, deferrals)
     -- wait for database to finish
     databasePromise:next(function()
         deferrals.update(string.format(Lang:t('info.join_server'), name))
-        deferrals.done()
+        if queue then
+            queue.awaitPlayerQueue(src --[[@as Source]], license, deferrals)
+        else
+            deferrals.done()
+        end
     end, function(err)
         deferrals.done(Lang:t('error.connecting_error'))
         lib.print.error(err)

server/queue.lua

@@ -0,0 +1,111 @@
+if GetConvar('qbx:enablequeue', 'true') == 'false' then return end
+
+-- Disable hardcap because it kicks the player when the server is full
+
+---@param resource string
+AddEventHandler('onResourceStarting', function(resource)
+    if resource == 'hardcap' then
+        lib.print.info('Preventing hardcap from starting...')
+        CancelEvent()
+    end
+end)
+
+if GetResourceState('hardcap'):find('start') then
+    lib.print.info('Stopping hardcap...')
+    StopResource('hardcap')
+end
+
+-- Queue code
+
+local maxPlayers = GlobalState.MaxPlayers
+
+---Player license to queue position map.
+---@type table<string, integer>
+local playerPositions = {}
+local queueSize = 0
+
+---@param license string
+local function enqueue(license)
+    queueSize += 1
+    playerPositions[license] = queueSize
+end
+
+---@param license string
+local function dequeue(license)
+    local pos = playerPositions[license]
+
+    queueSize -= 1
+    playerPositions[license] = nil
+
+    -- decrease the positions of players who are after the current player in queue
+    for k, v in pairs(playerPositions) do
+        if v > pos then
+            playerPositions[k] -= 1
+        end
+    end
+end
+
+---Map of player licenses that passed the queue and are downloading server content.
+---Needs to be saved because these players won't be part of regular player counts such as `GetNumPlayerIndices`.
+---@type table<string, true>
+local joiningPlayers = {}
+local joiningPlayerCount = 0
+
+---@param license string
+local function addPlayerJoining(license)
+    if not joiningPlayers[license] then
+        joiningPlayerCount += 1
+    end
+    joiningPlayers[license] = true
+end
+
+---@param license string
+local function removePlayerJoining(license)
+    if joiningPlayers[license] then
+        joiningPlayerCount -= 1
+    end
+    joiningPlayers[license] = nil
+end
+
+---@param source Source
+---@param license string
+---@param deferrals Deferrals
+local function awaitPlayerQueue(source, license, deferrals)
+    if playerPositions[license] then
+        deferrals.done(Lang:t('error.already_in_queue'))
+        return
+    end
+
+    enqueue(license)
+
+    -- wait until the player disconnected or until there are available slots and the player is first in queue
+    while DoesPlayerExist(source --[[@as string]]) and ((GetNumPlayerIndices() + joiningPlayerCount) >= maxPlayers or playerPositions[license] > 1) do
+        deferrals.update(Lang:t('info.in_queue', {
+            queuePos = playerPositions[license],
+            queueSize = queueSize,
+        }))
+
+        Wait(1000)
+    end
+
+    -- if the player disconnected while waiting in queue
+    if not DoesPlayerExist(source --[[@as string]]) then
+        dequeue(license)
+        return
+    end
+
+    addPlayerJoining(license)
+    dequeue(license)
+    deferrals.done()
+
+    -- wait until the player finally joins or disconnects while installing server content
+    -- this may result in waiting ~2 additional minutes if the player disconnects as FXServer will think that the player exists
+    while DoesPlayerExist(source --[[@as string]]) do
+        Wait(1000)
+    end
+    removePlayerJoining(license)
+end
+
+return {
+    awaitPlayerQueue = awaitPlayerQueue,
+}