Use a modal to configure announcement messages

In addition, wrote a new static class just for receiving ModalSubmitted events in case any more modals may be handled in the future

ApplicationCommands/ConfigModule.cs

@@ -23,6 +23,10 @@ public class ConfigModule : BotModuleBase {
         private const string HelpSubCmdMessage = "Modify the announcement message.";
         private const string HelpSubCmdPing = "Set whether to ping users mentioned in the announcement.";
 
+        internal const string ModalCidAnnounce = "edit-announce";
+        private const string ModalComCidSingle = "msg-single";
+        private const string ModalComCidMulti = "msg-multi";
+
         [SlashCommand("help", "Show information regarding announcement messages.")]
         public async Task CmdAnnounceHelp() {
             const string subcommands =
@@ -62,11 +66,49 @@ public class ConfigModule : BotModuleBase {
 
         [SlashCommand("set-message", HelpPfxModOnly + HelpSubCmdMessage)]
         public async Task CmdSetMessage() {
-            // TODO implement this
+            var gconf = await Context.Guild.GetConfigAsync().ConfigureAwait(false);
-            var pfx = TextCommands.CommandsCommon.CommandPrefix;
+
-            await RespondAsync(":x: Sorry, changing the announcement message via slash commands is not yet available. " +
+            var txtSingle = new TextInputBuilder() {
-                "Please use the corresponding text command: " +
+                Label = "Single - Message for one birthday",
-                $"`{pfx}config message` for single, `{pfx}config message-pl` for multi.", ephemeral: true);
+                CustomId = ModalComCidSingle,
+                Style = TextInputStyle.Paragraph,
+                MaxLength = 1500,
+                Required = false,
+                Placeholder = BackgroundServices.BirthdayRoleUpdate.DefaultAnnounce,
+                Value = gconf.AnnounceMessages.Item1 ?? ""
+            };
+            var txtMulti = new TextInputBuilder() {
+                Label = "Multi - Message for multiple birthdays",
+                CustomId = ModalComCidMulti,
+                Style = TextInputStyle.Paragraph,
+                MaxLength = 1500,
+                Required = false,
+                Placeholder = BackgroundServices.BirthdayRoleUpdate.DefaultAnnouncePl,
+                Value = gconf.AnnounceMessages.Item2 ?? ""
+            };
+
+            var form = new ModalBuilder()
+                .WithTitle("Edit announcement message")
+                .WithCustomId(ModalCidAnnounce)
+                .AddTextInput(txtSingle)
+                .AddTextInput(txtMulti)
+                .Build();
+
+            await RespondWithModalAsync(form).ConfigureAwait(false);
+        }
+
+        internal static async Task CmdSetMessageResponse(SocketModal modal, SocketGuildChannel channel,
+                                                         Dictionary<string, SocketMessageComponentData> data) {
+            string? newSingle = data[ModalComCidSingle].Value;
+            string? newMulti = data[ModalComCidMulti].Value;
+            if (string.IsNullOrWhiteSpace(newSingle)) newSingle = null;
+            if (string.IsNullOrWhiteSpace(newMulti)) newMulti = null;
+
+            var gconf = await channel.Guild.GetConfigAsync().ConfigureAwait(false);
+            gconf.AnnounceMessages = (newSingle, newMulti);
+            await gconf.UpdateAsync().ConfigureAwait(false);
+
+            await modal.RespondAsync(":white_check_mark: Announcement messages have been updated.");
         }
 
         [SlashCommand("set-ping", HelpPfxModOnly + HelpSubCmdPing)]

ApplicationCommands/ModalResponder.cs

@@ -0,0 +1,39 @@
+namespace BirthdayBot.ApplicationCommands;
+
+/// <summary>
+/// An instance-less class meant to handle incoming submitted modals.
+/// </summary>
+static class ModalResponder {
+    private delegate Task Responder(SocketModal modal, SocketGuildChannel channel,
+                                    Dictionary<string, SocketMessageComponentData> data);
+
+    internal static async Task DiscordClient_ModalSubmitted(ShardInstance inst, SocketModal arg) {
+        Responder handler = arg.Data.CustomId switch {
+            ConfigModule.SubCmdsConfigAnnounce.ModalCidAnnounce => ConfigModule.SubCmdsConfigAnnounce.CmdSetMessageResponse,
+            _ => DefaultHandler
+        };
+
+        var data = arg.Data.Components.ToDictionary(k => k.CustomId);
+
+        if (arg.Channel is not SocketGuildChannel channel) {
+            inst.Log(nameof(ModalResponder), $"Modal of type `{arg.Data.CustomId}` but channel data unavailable. " +
+                $"Sender ID {arg.User.Id}, name {arg.User}.");
+            await arg.RespondAsync(":x: Invalid request. Are you trying this command from a channel the bot can't see?")
+                .ConfigureAwait(false);
+            return;
+        }
+
+        try {
+            inst.Log(nameof(ModalResponder), $"Modal of type `{arg.Data.CustomId}` at {channel.Guild}!{arg.User}.");
+            await handler(arg, channel, data).ConfigureAwait(false);
+        } catch (Exception e) {
+            inst.Log(nameof(ModalResponder), $"Unhandled exception. {e}");
+            // TODO when implementing proper application error logging, see here
+            await arg.RespondAsync(ShardInstance.InternalError);
+        }
+    }
+
+    private static async Task DefaultHandler(SocketModal modal, SocketGuildChannel channel,
+                                             Dictionary<string, SocketMessageComponentData> data)
+        => await modal.RespondAsync(":x: ...???");
+}

ShardInstance.cs

@@ -49,6 +49,7 @@ public sealed class ShardInstance : IDisposable {
         _interactionService = _services.GetRequiredService<InteractionService>();
         DiscordClient.InteractionCreated += DiscordClient_InteractionCreated;
         _interactionService.SlashCommandExecuted += InteractionService_SlashCommandExecuted;
+        DiscordClient.ModalSubmitted += modal => { return ModalResponder.DiscordClient_ModalSubmitted(this, modal); };
 
         // Background task constructor begins background processing immediately.
         _background = new ShardBackgroundWorker(this);
@@ -75,7 +76,7 @@ public sealed class ShardInstance : IDisposable {
         Log(nameof(ShardInstance), "Instance disposed.");
     }
 
-    public void Log(string source, string message) => Program.Log($"Shard {ShardId:00}] [{source}", message);
+    internal void Log(string source, string message) => Program.Log($"Shard {ShardId:00}] [{source}", message);
 
     private Task Client_Log(LogMessage arg) {
         // Suppress certain messages