Prototyped stream notifications like CheeseBot

src/commands/admin.ts

@@ -164,6 +164,26 @@ export default new Command({
                             })
                         })
                     }
+                }),
+                stream: new Command({
+                    description: "Set a channel to send stream notifications.",
+                    async run($) {
+                        if ($.guild) {
+                            const guild = Storage.getGuild($.guild.id);
+
+                            if (guild.streamingChannel) {
+                                guild.streamingChannel = null;
+                                $.channel.send("Removed your server's stream notifications channel.");
+                            } else {
+                                guild.streamingChannel = $.channel.id;
+                                $.channel.send(`Set your server's stream notifications channel to ${$.channel}.`);
+                            }
+
+                            Storage.save();
+                        } else {
+                            $.channel.send("You must use this command in a server.");
+                        }
+                    }
                 })
             }
         }),

src/commands/utilities/streaminfo.ts

@@ -0,0 +1,18 @@
+import Command from "../../core/command";
+import {streamList, getStreamEmbed} from "../../events/voiceStateUpdate";
+
+export default new Command({
+    description: "Sets the description of your stream. You can embed links by writing `[some name](some link)`",
+    async run($) {
+        const userID = $.author.id;
+
+        if (streamList.has(userID)) {
+            const stream = streamList.get(userID)!;
+            stream.description = $.args.join(" ") || undefined;
+            stream.message.edit(getStreamEmbed(stream.streamer, stream.channel, stream.description));
+        } else {
+            // Alternatively, I could make descriptions last outside of just one stream.
+            $.channel.send("You can only use this command when streaming.");
+        }
+    }
+});

src/core/structures.ts

@@ -58,11 +58,13 @@ class Guild {
     public welcomeType: "none" | "text" | "graphical";
     public welcomeChannel: string | null;
     public welcomeMessage: string | null;
+    public streamingChannel: string | null;
 
     constructor(data?: GenericJSON) {
         this.prefix = select(data?.prefix, null, String);
         this.welcomeChannel = select(data?.welcomeChannel, null, String);
         this.welcomeMessage = select(data?.welcomeMessage, null, String);
+        this.streamingChannel = select(data?.streamingChannel, null, String);
 
         switch (data?.welcomeType) {
             case "text":

src/events/channelUpdate.ts

@@ -0,0 +1,14 @@
+import Event from "../core/event";
+import {streamList, getStreamEmbed} from "./voiceStateUpdate";
+
+export default new Event<"channelUpdate">({
+    async on(before, after) {
+        if (before.type === "voice" && after.type === "voice") {
+            for (const {streamer, channel, description, message} of streamList.values()) {
+                if (after.id === channel.id) {
+                    message.edit(getStreamEmbed(streamer, channel, description));
+                }
+            }
+        }
+    }
+});

src/events/voiceStateUpdate.ts

@@ -0,0 +1,74 @@
+import {GuildMember, VoiceChannel, MessageEmbed, TextChannel, Permissions, Message, Collection} from "discord.js";
+import Event from "../core/event";
+import $ from "../core/lib";
+import {Storage} from "../core/structures";
+import {client} from "../index";
+
+type Stream = {
+    streamer: GuildMember;
+    channel: VoiceChannel;
+    description?: string;
+    message: Message;
+};
+
+// A list of user IDs and message embeds.
+export const streamList = new Collection<string, Stream>();
+
+// Probably find a better, DRY way of doing this.
+export function getStreamEmbed(streamer: GuildMember, channel: VoiceChannel, description?: string): MessageEmbed {
+    const user = streamer.user;
+    const embed = new MessageEmbed()
+        .setTitle(`Stream: \`#${channel.name}\``)
+        .setAuthor(
+            streamer.nickname ?? user.username,
+            user.avatarURL({
+                dynamic: true,
+                format: "png"
+            }) ?? user.defaultAvatarURL
+        )
+        .setColor(streamer.displayColor);
+
+    if (description) {
+        embed.setDescription(description);
+    }
+
+    return embed;
+}
+
+export default new Event<"voiceStateUpdate">({
+    async on(before, after) {
+        const isStartStreamEvent = !before.streaming && after.streaming;
+        const isStopStreamEvent = before.streaming && (!after.streaming || !after.channel); // If you were streaming before but now are either not streaming or have left the channel.
+        // Note: isStopStreamEvent can be called twice in a row - If Discord crashes/quits while you're streaming, it'll call once with a null channel and a second time with a channel.
+
+        if (isStartStreamEvent || isStopStreamEvent) {
+            const {streamingChannel} = Storage.getGuild(after.guild.id);
+
+            if (streamingChannel) {
+                const member = after.member!;
+                const voiceChannel = after.channel!;
+                const textChannel = client.channels.cache.get(streamingChannel);
+
+                if (textChannel && textChannel instanceof TextChannel) {
+                    if (isStartStreamEvent) {
+                        streamList.set(member.id, {
+                            streamer: member,
+                            channel: voiceChannel,
+                            message: await textChannel.send(getStreamEmbed(member, voiceChannel))
+                        });
+                    } else if (isStopStreamEvent) {
+                        if (streamList.has(member.id)) {
+                            const {message} = streamList.get(member.id)!;
+                            message.delete();
+                            streamList.delete(member.id);
+                        }
+                    }
+                } else {
+                    $.error(
+                        `The streaming notifications channel ${streamingChannel} for guild ${after.guild.id} either doesn't exist or isn't a text channel.`
+                    );
+                }
+            }
+        }
+    }
+});