From 12d85c982e20adba182f73b7576a02d62b0b9ca4 Mon Sep 17 00:00:00 2001
From: Cadence Ember <cadence@disroot.org>
Date: Thu, 7 Mar 2024 10:17:39 +1300
Subject: [PATCH] Allow Matrixers to @room if Discorders can too

---
 d2m/actions/create-room.js      |  7 ++++++-
 d2m/actions/create-room.test.js | 11 +++++++++++
 discord/utils.js                |  2 +-
 test/data.js                    | 22 +++++++++++++++++-----
 4 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/d2m/actions/create-room.js b/d2m/actions/create-room.js
index 0dea2839..a8d28465 100644
--- a/d2m/actions/create-room.js
+++ b/d2m/actions/create-room.js
@@ -12,6 +12,8 @@ const file = sync.require("../../matrix/file")
 const api = sync.require("../../matrix/api")
 /** @type {import("../../matrix/kstate")} */
 const ks = sync.require("../../matrix/kstate")
+/** @type {import("../../discord/utils")} */
+const utils = sync.require("../../discord/utils")
 /** @type {import("./create-space")}) */
 const createSpace = sync.require("./create-space") // watch out for the require loop
 
@@ -119,6 +121,9 @@ async function channelToKState(channel, guild) {
 		join_rules = {join_rule: PRIVACY_ENUMS.ROOM_JOIN_RULES[privacyLevel]}
 	}
 
+	const everyonePermissions = utils.getPermissions([], guild.roles, undefined, channel.permission_overwrites)
+	const everyoneCanMentionEveryone = utils.hasAllPermissions(everyonePermissions, ["MentionEveryone"])
+
 	const channelKState = {
 		"m.room.name/": {name: convertedName},
 		"m.room.topic/": {topic: convertedTopic},
@@ -136,7 +141,7 @@ async function channelToKState(channel, guild) {
 				"m.room.avatar": 0
 			},
 			notifications: {
-				room: 20 // TODO: Matrix users should have the same abilities as unprivileged Discord members. So make this automatically configured based on the guild or channel's default mention everyone permissions. That way if unprivileged Discord members can mention everyone, Matrix users can too.
+				room: everyoneCanMentionEveryone ? 0 : 20
 			},
 			users: reg.ooye.invite.reduce((a, c) => (a[c] = 100, a), {})
 		},
diff --git a/d2m/actions/create-room.test.js b/d2m/actions/create-room.test.js
index 93f9203b..be0febbc 100644
--- a/d2m/actions/create-room.test.js
+++ b/d2m/actions/create-room.test.js
@@ -1,5 +1,6 @@
 // @ts-check
 
+const mixin = require("mixin-deep")
 const {channelToKState, _convertNameAndTopic} = require("./create-room")
 const {kstateStripConditionals} = require("../../matrix/kstate")
 const {test} = require("supertape")
@@ -39,6 +40,16 @@ test("channel2room: invite-only privacy room", async t => {
 	)
 })
 
+test("channel2room: room where limited people can mention everyone", async t => {
+	const limitedGuild = mixin({}, testData.guild.general)
+	limitedGuild.roles[0].permissions = (BigInt(limitedGuild.roles[0].permissions) - 131072n).toString()
+	const limitedRoom = mixin({}, testData.room.general, {"m.room.power_levels/": {notifications: {room: 20}}})
+	t.deepEqual(
+		kstateStripConditionals(await channelToKState(testData.channel.general, limitedGuild).then(x => x.channelKState)),
+		limitedRoom
+	)
+})
+
 test("convertNameAndTopic: custom name and topic", t => {
 	t.deepEqual(
 		_convertNameAndTopic({id: "123", name: "the-twilight-zone", topic: "Spooky stuff here. :ghost:", type: 0}, {id: "456"}, "hauntings"),
diff --git a/discord/utils.js b/discord/utils.js
index 6b6b6025..2726a1ad 100644
--- a/discord/utils.js
+++ b/discord/utils.js
@@ -26,7 +26,7 @@ function getPermissions(userRoles, guildRoles, userID, channelOverwrites) {
 	}
 
 	if (channelOverwrites) {
-		/** @type {((overwrite: Required<DiscordTypes.APIGuildChannel>["permission_overwrites"][0]) => any)[]} */
+		/** @type {((overwrite: Required<DiscordTypes.APIOverwrite>) => any)[]} */
 		const actions = [
 			// Channel @everyone deny
 			overwrite => overwrite.id === everyoneID && (allowed &= ~BigInt(overwrite.deny)),
diff --git a/test/data.js b/test/data.js
index 61ee5d0e..c1653221 100644
--- a/test/data.js
+++ b/test/data.js
@@ -47,6 +47,9 @@ module.exports = {
 				},
 				users: {
 					"@test_auto_invite:example.org": 100
+				},
+				notifications: {
+					room: 0
 				}
 			},
 			"chat.schildi.hide_ui/read_receipts": {hidden: true},
@@ -98,7 +101,6 @@ module.exports = {
 			icon: "a_f83622e09ead74f0c5c527fe241f8f8c",
 			emojis: [
 				{
-					version: 0,
 					roles: [],
 					require_colons: true,
 					name: "hippo",
@@ -108,7 +110,6 @@ module.exports = {
 					animated: false
 				},
 				{
-					version: 0,
 					roles: [],
 					require_colons: true,
 					name: "hipposcope",
@@ -121,7 +122,20 @@ module.exports = {
 			premium_subscription_count: 14,
 			roles: [
 				{
-					version: 1696964862461,
+					unicode_emoji: null,
+					tags: {},
+					position: 0,
+					permissions: '559623605575360',
+					name: '@everyone',
+					mentionable: false,
+					managed: false,
+					id: '112760669178241024',
+					icon: null,
+					hoist: false,
+					flags: 0,
+					color: 0
+				},
+				{
 					unicode_emoji: null,
 					tags: {},
 					position: 22,
@@ -135,7 +149,6 @@ module.exports = {
 					flags: 0,
 					color: 0
 				}, {
-					version: 1696964862776,
 					unicode_emoji: null,
 					tags: {},
 					position: 131,
@@ -149,7 +162,6 @@ module.exports = {
 					flags: 0,
 					color: 11076095
 				}, {
-					version: 1696964862698,
 					unicode_emoji: '🍂',
 					tags: {},
 					position: 102,