From a2e3f06e8e65949cb52dd8049d364ae6b2a80d40 Mon Sep 17 00:00:00 2001
From: Cadence Ember <cadence@disroot.org>
Date: Sat, 31 Aug 2024 17:02:46 +1200
Subject: [PATCH] Unbridge rooms when their channel is deleted

---
 d2m/actions/create-room.js       | 20 ++++++++++++++------
 d2m/discord-packets.js           |  3 +++
 d2m/event-dispatcher.js          | 13 +++++++++++++
 discord/register-interactions.js |  2 +-
 4 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/d2m/actions/create-room.js b/d2m/actions/create-room.js
index a6b61cd3..51eef6cd 100644
--- a/d2m/actions/create-room.js
+++ b/d2m/actions/create-room.js
@@ -370,11 +370,16 @@ async function _unbridgeRoom(channelID) {
 	/** @ts-ignore @type {DiscordTypes.APIGuildChannel} */
 	const channel = discord.channels.get(channelID)
 	assert.ok(channel)
-	return unbridgeDeletedChannel(channel.id, channel.guild_id)
+	assert.ok(channel.guild_id)
+	return unbridgeDeletedChannel(channel, channel.guild_id)
 }
 
-async function unbridgeDeletedChannel(channelID, guildID) {
-	const roomID = select("channel_room", "room_id", {channel_id: channelID}).pluck().get()
+/**
+ * @param {DiscordTypes.APIGuildChannel} channel
+ * @param {string} guildID
+ */
+async function unbridgeDeletedChannel(channel, guildID) {
+	const roomID = select("channel_room", "room_id", {channel_id: channel.id}).pluck().get()
 	assert.ok(roomID)
 	const spaceID = select("guild_space", "space_id", {guild_id: guildID}).pluck().get()
 	assert.ok(spaceID)
@@ -384,7 +389,11 @@ async function unbridgeDeletedChannel(channelID, guildID) {
 	await api.sendState(spaceID, "m.space.child", roomID, {})
 
 	// remove declaration that the room is bridged
-	await api.sendState(roomID, "uk.half-shot.bridge", `moe.cadence.ooye://discord/${guildID}/${channelID}`, {})
+	await api.sendState(roomID, "uk.half-shot.bridge", `moe.cadence.ooye://discord/${guildID}/${channel.id}`, {})
+	if ("topic" in channel) {
+		// previously the Matrix topic would say the channel ID. we should remove that
+		await api.sendState(roomID, "m.room.topic", "", {topic: channel.topic || ""})
+	}
 
 	// send a notification in the room
 	await api.sendEvent(roomID, "m.room.message", {
@@ -396,8 +405,7 @@ async function unbridgeDeletedChannel(channelID, guildID) {
 	await api.leaveRoom(roomID)
 
 	// delete room from database
-	const {changes} = db.prepare("DELETE FROM channel_room WHERE room_id = ? AND channel_id = ?").run(roomID, channelID)
-	assert.equal(changes, 1)
+	db.prepare("DELETE FROM channel_room WHERE room_id = ? AND channel_id = ?").run(roomID, channel.id)
 }
 
 /**
diff --git a/d2m/discord-packets.js b/d2m/discord-packets.js
index ed47faea..f619f2b6 100644
--- a/d2m/discord-packets.js
+++ b/d2m/discord-packets.js
@@ -147,6 +147,9 @@ const utils = {
 				} else if (message.t === "CHANNEL_PINS_UPDATE") {
 					await eventDispatcher.onChannelPinsUpdate(client, message.d)
 
+				} else if (message.t === "CHANNEL_DELETE") {
+					await eventDispatcher.onChannelDelete(client, message.d)
+
 				} else if (message.t === "THREAD_CREATE") {
 					// @ts-ignore
 					await eventDispatcher.onThreadCreate(client, message.d)
diff --git a/d2m/event-dispatcher.js b/d2m/event-dispatcher.js
index 57cb72cd..235248c8 100644
--- a/d2m/event-dispatcher.js
+++ b/d2m/event-dispatcher.js
@@ -230,6 +230,19 @@ module.exports = {
 		await updatePins.updatePins(data.channel_id, roomID, convertedTimestamp)
 	},
 
+	/**
+	 * @param {import("./discord-client")} client
+	 * @param {DiscordTypes.GatewayChannelDeleteDispatchData} channel
+	 */
+	async onChannelDelete(client, channel) {
+		const guildID = channel["guild_id"]
+		if (!guildID) return // channel must have been a DM channel or something
+		const roomID = select("channel_room", "room_id", {channel_id: channel.id}).pluck().get()
+		if (!roomID) return // channel wasn't being bridged in the first place
+		// @ts-ignore
+		await createRoom.unbridgeDeletedChannel(channel, guildID)
+	},
+
 	/**
 	 * @param {import("./discord-client")} client
 	 * @param {DiscordTypes.GatewayMessageCreateDispatchData} message
diff --git a/discord/register-interactions.js b/discord/register-interactions.js
index a6e43323..553c6db9 100644
--- a/discord/register-interactions.js
+++ b/discord/register-interactions.js
@@ -17,7 +17,7 @@ discord.snow.interaction.bulkOverwriteApplicationCommands(id, [{
 	name: "Permissions",
 	contexts: [DiscordTypes.InteractionContextType.Guild],
 	type: DiscordTypes.ApplicationCommandType.Message,
-	default_member_permissions: String(DiscordTypes.PermissionFlagsBits.KickMembers)
+	default_member_permissions: String(DiscordTypes.PermissionFlagsBits.KickMembers | DiscordTypes.PermissionFlagsBits.ManageRoles)
 }, {
 	name: "invite",
 	contexts: [DiscordTypes.InteractionContextType.Guild],