From 0e88cd35476e341c6c0a8bf5599188e5f1a55c52 Mon Sep 17 00:00:00 2001
From: Superchupu <53496941+SuperchupuDev@users.noreply.github.com>
Date: Wed, 12 Jul 2023 12:26:52 +0200
Subject: [PATCH] fix: improve message permission checks

---
 src/classes/Detector.ts     |  7 ++++---
 src/events/messageCreate.ts | 11 +++++------
 src/events/messageUpdate.ts |  6 ++----
 src/util/index.ts           |  1 +
 src/util/sendable.ts        | 20 ++++++++++++++++++++
 5 files changed, 32 insertions(+), 13 deletions(-)
 create mode 100644 src/util/sendable.ts

diff --git a/src/classes/Detector.ts b/src/classes/Detector.ts
index 18e0a1e..84acbbf 100644
--- a/src/classes/Detector.ts
+++ b/src/classes/Detector.ts
@@ -1,6 +1,7 @@
 import { setTimeout } from 'node:timers/promises';
 import type { Application } from '#classes';
 import { env } from '#env';
+import { isSendable } from '#util';
 import {
   type APIEmbedField,
   type GuildMember,
@@ -64,8 +65,8 @@ export class Detector {
   }
 
   async reply(message: Message<true>, edited: boolean) {
-    const permissions = message.channel.permissionsFor(this.client.user);
-    if (edited || (permissions && !permissions.has(PermissionFlagsBits.SendMessages))) {
+    const sendable = await isSendable(message.channel);
+    if (edited || !sendable) {
       return;
     }
 
@@ -226,7 +227,7 @@ export class Detector {
       }
     }
 
-    if (channel?.permissionsFor(this.client.user)?.has(PermissionFlagsBits.SendMessages) && channel.viewable) {
+    if (channel && (await isSendable(channel))) {
       await channel.send({
         embeds: [
           {
diff --git a/src/events/messageCreate.ts b/src/events/messageCreate.ts
index ccbbcbe..1dabd56 100644
--- a/src/events/messageCreate.ts
+++ b/src/events/messageCreate.ts
@@ -1,26 +1,25 @@
 import type { Application } from '#classes';
-import { type Message, MessageType, PermissionFlagsBits } from 'discord.js';
+import { isSendable } from '#util';
+import { type Message, MessageType } from 'discord.js';
 
 export async function run(client: Application<true>, message: Message<true>) {
-  const permissions = message.channel.permissionsFor(client.user);
   if (
     message.author.bot ||
     message.author.system ||
     (message.type !== MessageType.Default && message.type !== MessageType.Reply) ||
-    !message.content ||
-    (permissions && !permissions.has(PermissionFlagsBits.SendMessages))
+    !message.content
   ) {
     return;
   }
 
-  if (message.content === `<@${client.user.id}>`) {
+  if (message.content === `<@${client.user.id}>` && (await isSendable(message.channel))) {
     return message.channel.send('Hi! Type `/` to see my commands');
   }
 
   const [commandName] = message.content.slice(2).split(' ');
   const command = client.chatInputCommands.get(commandName);
 
-  if (message.content.startsWith('h!') && command && !command.dev) {
+  if (message.content.startsWith('h!') && command && !command.dev && (await isSendable(message.channel))) {
     const commands = client.application.commands.cache.size
       ? client.application.commands.cache
       : await client.application.commands.fetch();
diff --git a/src/events/messageUpdate.ts b/src/events/messageUpdate.ts
index f5bd706..9969345 100644
--- a/src/events/messageUpdate.ts
+++ b/src/events/messageUpdate.ts
@@ -1,5 +1,5 @@
 import type { Application } from '#classes';
-import { type Message, MessageType, PermissionFlagsBits } from 'discord.js';
+import { type Message, MessageType } from 'discord.js';
 
 export async function run(client: Application<true>, oldMessage: Message, message: Message<true>) {
   if (message.partial) {
@@ -10,13 +10,11 @@ export async function run(client: Application<true>, oldMessage: Message, messag
     }
   }
 
-  const permissions = message.channel.permissionsFor(client.user);
   if (
     message.author.bot ||
     message.author.system ||
     (message.type !== MessageType.Default && message.type !== MessageType.Reply) ||
-    !message.content ||
-    (permissions && !permissions.has(PermissionFlagsBits.SendMessages))
+    !message.content
   ) {
     return;
   }
diff --git a/src/util/index.ts b/src/util/index.ts
index 9f6b132..ec63589 100644
--- a/src/util/index.ts
+++ b/src/util/index.ts
@@ -1,4 +1,5 @@
 export { default as changelog } from './changelog.json' assert { type: 'json' };
 export * from './fetchTags.js';
 export * from './files.js';
+export * from './sendable.js';
 export * from './types.js';
diff --git a/src/util/sendable.ts b/src/util/sendable.ts
new file mode 100644
index 0000000..1ffab92
--- /dev/null
+++ b/src/util/sendable.ts
@@ -0,0 +1,20 @@
+import { type GuildTextBasedChannel, PermissionFlagsBits } from 'discord.js';
+
+export async function isSendable(channel: GuildTextBasedChannel) {
+  if (channel.isThread()) {
+    return channel.sendable;
+  }
+
+  const permissions = channel.permissionsFor(channel.client.user);
+
+  if (!permissions || !channel.viewable) {
+    return false;
+  }
+
+  if (permissions.has(PermissionFlagsBits.Administrator, false)) {
+    return true;
+  }
+
+  const clientMember = await channel.guild.members.fetchMe();
+  return permissions.has(PermissionFlagsBits.SendMessages, false) && !clientMember.isCommunicationDisabled();
+}