send welcome message when added to server

src/bot/modules/event_handler.ts

@@ -2,14 +2,16 @@ import { ulid } from "ulid";
 import { client } from "../..";
 import Infraction from "../../struct/antispam/Infraction";
 import InfractionType from "../../struct/antispam/InfractionType";
-import { storeInfraction } from "../util";
+import logger from "../logger";
+import { hasPermForChannel, storeInfraction } from "../util";
+import { DEFAULT_PREFIX } from "./command_handler";
 
 // Listen to system messages
 client.on('message', async message => {
     if (typeof message.content != 'object') return;
 
     let sysMsg = message.asSystemMessage;
-    
+
     switch(sysMsg.type) {
         case 'user_kicked':
         case 'user_banned':
@@ -41,3 +43,38 @@ client.on('message', async message => {
         case 'user_left'  : break;
     }
 });
+
+// Send a message when added to a server
+client.on('member/join', (member) => {
+    if (member._id.user != client.user?._id) return;
+
+    let url = `https://rvembed.janderedev.xyz/embed`
+            + `?title=${encodeURIComponent('Hi there, thanks for adding me!')}`
+            + `&description=${encodeURIComponent(`My prefix is "${DEFAULT_PREFIX}", `
+                + `but you can also @mention me instead.\nCheck out ${DEFAULT_PREFIX}help to get started!`)}`
+            + `&link=${encodeURIComponent(`/bot/${client.user._id}`)}`
+            + `&redir=${encodeURIComponent(`https://github.com/janderedev/revolt-automod`)}`
+            + `&color=${encodeURIComponent("#ff6e6d")}`
+            + `&image=${encodeURIComponent(client.user.generateAvatarURL({ size: 128 }))}`
+            + `&image_large=false`;
+
+    if (!member.server) return;
+
+    let channels = member.server.channels.filter(
+        c => c
+         && c.channel_type == 'TextChannel'
+         && hasPermForChannel(member, c, 'SendMessage')
+         && hasPermForChannel(member, c, 'EmbedLinks')
+    );
+
+    // Attempt to find an appropriate channel, otherwise use the first one available
+    let channel = channels.find(c => c?.name?.toLowerCase() == 'welcome')
+               || channels.find(c => c?.name?.toLowerCase() == 'general')
+               || channels.find(c => c?.name?.toLowerCase() == 'bots')
+               || channels.find(c => c?.name?.toLowerCase() == 'spam')
+               || channels[0];
+
+    if (!channel) return logger.debug('Cannot send hello message: No suitable channel found');
+    channel.sendMessage(`[:wave:](${url} "Hi there!")`)
+        .catch(e => logger.debug('Cannot send hello message: ' + e));
+});