Fix Ready and AlwaysDownloadUsers

Ready could fire before downloading all guild data and downloading guild users one guild per time without gateway intents is a waste of a gateway request that can support up to 1000.

src/Discord.Net.WebSocket/DiscordSocketClient.Events.cs

@@ -21,7 +21,12 @@ namespace Discord.WebSocket
             remove { _disconnectedEvent.Remove(value); }
         }
         private readonly AsyncEvent<Func<Exception, Task>> _disconnectedEvent = new AsyncEvent<Func<Exception, Task>>();
-        /// <summary> Fired when guild data has finished downloading. </summary>
+        /// <summary>
+        ///     Fired when guild data has finished downloading.
+        /// </summary>
+        /// <remarks>
+        ///     It is possible that some guilds might be unsynced if <see cref="DiscordSocketConfig.MaxWaitBetweenGuildAvailablesBeforeReady" /> was not long enough to receive all GUILD_AVAILABLES before READY.
+        /// </remarks>
         public event Func<Task> Ready
         {
             add { _readyEvent.Add(value); }

src/Discord.Net.WebSocket/DiscordSocketClient.cs

@@ -167,7 +167,7 @@ namespace Discord.WebSocket
 
             GuildAvailable += g =>
             {
-                if (ConnectionState == ConnectionState.Connected && AlwaysDownloadUsers && !g.HasAllMembers)
+                if (_guildDownloadTask?.IsCompleted == true && ConnectionState == ConnectionState.Connected && AlwaysDownloadUsers && !g.HasAllMembers)
                 {
                     var _ = g.DownloadUsersAsync();
                 }
@@ -368,7 +368,7 @@ namespace Discord.WebSocket
         {
             var cachedGuilds = guilds.ToImmutableArray();
 
-            const short batchSize = 50;
+            const short batchSize = 1000; //TODO: Gateway Intents will limit to a maximum of 1 guild_id
             ulong[] batchIds = new ulong[Math.Min(batchSize, cachedGuilds.Length)];
             Task[] batchTasks = new Task[batchIds.Length];
             int batchCount = (cachedGuilds.Length + (batchSize - 1)) / batchSize;
@@ -576,6 +576,9 @@ namespace Discord.WebSocket
                                             }
                                             else if (_connection.CancelToken.IsCancellationRequested)
                                                 return;
+                                            
+                                            if (BaseConfig.AlwaysDownloadUsers)
+                                                _ = DownloadUsersAsync(Guilds.Where(x => x.IsAvailable && !x.HasAllMembers));
 
                                             await TimedInvokeAsync(_readyEvent, nameof(Ready)).ConfigureAwait(false);
                                             await _gatewayLogger.InfoAsync("Ready").ConfigureAwait(false);
@@ -1742,7 +1745,7 @@ namespace Discord.WebSocket
             try
             {
                 await logger.DebugAsync("GuildDownloader Started").ConfigureAwait(false);
-                while ((_unavailableGuildCount != 0) && (Environment.TickCount - _lastGuildAvailableTime < 2000))
+                while ((_unavailableGuildCount != 0) && (Environment.TickCount - _lastGuildAvailableTime < BaseConfig.MaxWaitBetweenGuildAvailablesBeforeReady))
                     await Task.Delay(500, cancelToken).ConfigureAwait(false);
                 await logger.DebugAsync("GuildDownloader Stopped").ConfigureAwait(false);
             }

src/Discord.Net.WebSocket/DiscordSocketConfig.cs

@@ -124,6 +124,32 @@ namespace Discord.WebSocket
         /// </summary>
         public bool GuildSubscriptions { get; set; } = true;
 
+        /// <summary>
+        ///     Gets or sets the maximum wait time in milliseconds between GUILD_AVAILABLE events before firing READY.
+        ///
+        ///     If zero, READY will fire as soon as it is received and all guilds will be unavailable.
+        /// </summary>
+        /// <remarks>
+        ///     <para>This property is measured in milliseconds, negative values will throw an exception.</para>
+        ///     <para>If a guild is not received before READY, it will be unavailable.</para>
+        /// </remarks>
+        /// <returns>
+        ///     The maximum wait time in milliseconds between GUILD_AVAILABLE events before firing READY.
+        /// </returns>
+        /// <exception cref="System.ArgumentException">Value must be at least 0.</exception>
+        public int MaxWaitBetweenGuildAvailablesBeforeReady {
+            get
+            {
+                return _maxWaitForGuildAvailable;
+            }
+            set
+            {
+                Preconditions.AtLeast(value, 0, nameof(MaxWaitBetweenGuildAvailablesBeforeReady));
+                _maxWaitForGuildAvailable = value;
+            }
+        }
+        private int _maxWaitForGuildAvailable = 10000;
+
         /// <summary>
         ///     Initializes a default configuration.
         /// </summary>