Fix conflicts; rename a var to something more sensible; less string concat because Cadence said she doesn't like it.

src/m2d/actions/send-event.js

@@ -14,8 +14,6 @@ const channelWebhook = sync.require("./channel-webhook")
 const eventToMessage = sync.require("../converters/event-to-message")
 /** @type {import("../../matrix/api")}) */
 const api = sync.require("../../matrix/api")
-/** @type {import("../../matrix/utils")}) */
-const utils = sync.require("../../matrix/utils")
 /** @type {import("../../d2m/actions/register-user")} */
 const registerUser = sync.require("../../d2m/actions/register-user")
 /** @type {import("../../d2m/actions/edit-message")} */
@@ -23,6 +21,12 @@ const editMessage = sync.require("../../d2m/actions/edit-message")
 /** @type {import("../actions/emoji-sheet")} */
 const emojiSheet = sync.require("../actions/emoji-sheet")
 
+/**
+ * @type {Map<string, string>} room id -> mxid
+ * Keep track of the sender of the latest event per room, this is needed to trim display name runoff for subsequent messages
+ */
+const latestSenderPerRoom = sync.remember(() => new Map())
+
 /**
  * @param {DiscordTypes.RESTPostAPIWebhookWithTokenJSONBody & {files?: {name: string, file: Buffer | stream.Readable}[], pendingFiles?: ({name: string, mxc: string} | {name: string, mxc: string, key: string, iv: string} | {name: string, buffer: Buffer | stream.Readable})[]}} message
  * @returns {Promise<DiscordTypes.RESTPostAPIWebhookWithTokenJSONBody & {files?: {name: string, file: Buffer | stream.Readable}[]}>}
@@ -87,7 +91,12 @@ async function sendEvent(event) {
 
 	// no need to sync the matrix member to the other side. but if I did need to, this is where I'd do it
 
-	const di = {api, snow: discord.snow, mxcDownloader: emojiSheet.getAndConvertEmoji}
+	const di = {
+		api,
+		snow: discord.snow,
+		mxcDownloader: emojiSheet.getAndConvertEmoji,
+		noRunoff: latestSenderPerRoom.get(event.room_id) === event.sender
+	}
 
 	if (event.type === "org.matrix.msc3381.poll.end") {
 		// Validity already checked by dispatcher. Poll is definitely closed. Update it and DI necessary data.
@@ -193,3 +202,4 @@ async function sendEvent(event) {
 }
 
 module.exports.sendEvent = sendEvent
+module.exports.latestSenderPerRoom = latestSenderPerRoom

src/m2d/converters/event-to-message.js

@@ -538,7 +538,7 @@ async function getL1L2ReplyLine(called = false) {
  * @param {Ty.Event.Outer_M_Room_Message | Ty.Event.Outer_M_Room_Message_File | Ty.Event.Outer_M_Sticker | Ty.Event.Outer_M_Room_Message_Encrypted_File | Ty.Event.Outer_Org_Matrix_Msc3381_Poll_Start | Ty.Event.Outer_Org_Matrix_Msc3381_Poll_End} event
  * @param {DiscordTypes.APIGuild} guild
  * @param {DiscordTypes.APIGuildTextChannel} channel
- * @param {{api: import("../../matrix/api"), snow: import("snowtransfer").SnowTransfer, pollEnd?: {messageID: string}}} di simple-as-nails dependency injection for the matrix API
+ * @param {{api: import("../../matrix/api"), snow: import("snowtransfer").SnowTransfer, pollEnd?: {messageID: string}, noRunoff: boolean}} di simple-as-nails dependency injection for the matrix API
  */
 async function eventToMessage(event, guild, channel, di) {
 	let displayName = event.sender
@@ -561,7 +561,16 @@ async function eventToMessage(event, guild, channel, di) {
 
 	// MSC4144: Override display name and avatar from per-message profile if present
 	const perMessageProfile = event.content["com.beeper.per_message_profile"]
-	if (perMessageProfile?.displayname) displayName = perMessageProfile.displayname
+	if (perMessageProfile?.displayname) {
+		// TODO: Ideally this should filter on the "language" key, rather than just picking the first, once we're aware of the guild's preferred locale.
+		// Regardless, these are intended to be in preference order, and the PMP user could always choose to reorder them if the wrong choice is made here.
+		const pronouns = perMessageProfile["io.fsky.nyx.pronouns"]?.[0]?.summary
+		let pronounsSuffix = ""
+		if (pronouns) {
+			pronounsSuffix = ` (${pronouns})`
+		}
+		displayName = `${perMessageProfile.displayname}${pronounsSuffix} | ${displayName}`
+	}
 	if (perMessageProfile && "avatar_url" in perMessageProfile) {
 		if (perMessageProfile.avatar_url) {
 			// use provided avatar_url
@@ -577,7 +586,7 @@ async function eventToMessage(event, guild, channel, di) {
 	// put the excess characters into displayNameRunoff, later to be put at the top of the message
 	let [displayNameShortened, displayNameRunoff] = splitDisplayName(displayName)
 	// If the message type is m.emote, the full name is already included at the start of the message, so remove any runoff
-	if (event.type === "m.room.message" && event.content.msgtype === "m.emote") {
+	if (di?.noRunoff || (event.type === "m.room.message" && event.content.msgtype === "m.emote")) {
 		displayNameRunoff = ""
 	}
 

src/m2d/converters/event-to-message.test.js

@@ -5985,7 +5985,7 @@ test("event2message: com.beeper.per_message_profile overrides displayname and av
 			messagesToDelete: [],
 			messagesToEdit: [],
 			messagesToSend: [{
-				username: "Unstable Name",
+				username: "Unstable Name | cadence [they]",
 				content: "hello from unstable profile",
 				avatar_url: "https://bridge.example.org/download/matrix/maunium.net/hgXsKqlmRfpKvCZdUoWDkFQo?preset=avatar",
 				allowed_mentions: {
@@ -6018,7 +6018,7 @@ test("event2message: com.beeper.per_message_profile empty avatar_url clears avat
 			messagesToDelete: [],
 			messagesToEdit: [],
 			messagesToSend: [{
-				username: "No Avatar User",
+				username: "No Avatar User | cadence [they]",
 				content: "hello with cleared avatar",
 				avatar_url: "https://bridge.example.org/download/letter-avatar?letter=N&hue=90",
 				allowed_mentions: {
@@ -6054,7 +6054,7 @@ test("event2message: data-mx-profile-fallback element is stripped from formatted
 			messagesToDelete: [],
 			messagesToEdit: [],
 			messagesToSend: [{
-				username: "Tidus Herboren",
+				username: "Tidus Herboren | cadence [they]",
 				content: "one more test",
 				avatar_url: "https://bridge.example.org/download/matrix/maunium.net/hgXsKqlmRfpKvCZdUoWDkFQo?preset=avatar",
 				allowed_mentions: {
@@ -6087,7 +6087,7 @@ test("event2message: displayname prefix is stripped from plain body when per-mes
 			messagesToDelete: [],
 			messagesToEdit: [],
 			messagesToSend: [{
-				username: "Tidus Herboren",
+				username: "Tidus Herboren | cadence [they]",
 				content: "one more test",
 				avatar_url: "https://bridge.example.org/download/letter-avatar?letter=T&hue=90",
 				allowed_mentions: {
@@ -6098,6 +6098,57 @@ test("event2message: displayname prefix is stripped from plain body when per-mes
 	)
 })
 
+test("event2message: pronouns can be displayed with per-message profile", async t => {
+	t.deepEqual(
+		await eventToMessage({
+			type: "m.room.message",
+			sender: "@exa:sleeping.town",
+			content: {
+				msgtype: "m.text",
+				body: "Well, I can't really do it now...",
+				"com.beeper.per_message_profile": {
+					id: "Kryn",
+					displayname: "Kryn",
+					"eu.she-a.color": {
+						on_dark: "#FFCC00",
+						on_light: "#976800"
+					},
+					"io.fsky.nyx.pronouns": [{
+						language: "en",
+						summary: "fae/she"
+					}]
+				}
+			},
+			event_id: "$g07oYSZFWBkxohNEfywldwgcWj1hbhDzQ1sBAKvqOOU",
+			room_id: "!kLRqKKUQXcibIMtOpl:cadence.moe"
+		}, {}, {}, {
+			api: {
+				async getStateEvent(roomID, type, key) {
+					t.equal(type, "m.room.member")
+					t.equal(key, "@exa:sleeping.town")
+					return {
+						displayname: "Exa",
+						membership: "join"
+					}
+				}
+			}
+		}),
+		{
+			ensureJoined: [],
+			messagesToDelete: [],
+			messagesToEdit: [],
+			messagesToSend: [{
+				username: "Kryn (fae/she) | Exa",
+				content: "Well, I can't really do it now...",
+				avatar_url: "https://bridge.example.org/download/letter-avatar?letter=K&hue=150",
+				allowed_mentions: {
+					parse: ["users", "roles"]
+				}
+			}]
+		}
+	)
+})
+
 test("event2message: all unknown chess emojis are used for sprite sheet", async t => {
 	t.deepEqual(
 		await eventToMessage({

src/m2d/event-dispatcher.js

@@ -192,23 +192,23 @@ sync.addTemporaryListener(as, "type:m.room.message", guard("m.room.message",
  * @param {Ty.Event.Outer_M_Room_Message | Ty.Event.Outer_M_Room_Message_File} event it is a m.room.message because that's what this listener is filtering for
  */
 async event => {
-	if (utils.eventSenderIsFromDiscord(event.sender)) return
+	if (!utils.eventSenderIsFromDiscord(event.sender)){
 		if (await handleForums(event)) return
 	
 		let processCommands = true
 		if (event.content["m.relates_to"]?.rel_type === "m.thread") {
 			/**@type {string|null} */
-		let toRedact = event.room_id
+			let redactAndMoveShouldOccurIn = event.room_id
 			const bridgedTo = utils.getThreadRoomFromThreadEvent(event.content["m.relates_to"].event_id)
 			processCommands = false
 	
 			if (bridgedTo) event.room_id = bridgedTo;
-		else if (!await bridgeThread(event)) toRedact = null; //Don't remove anything, if there is nowhere to relocate it to.
+			else if (!await bridgeThread(event)) redactAndMoveShouldOccurIn = null; //Don't remove anything, if there is nowhere to relocate it to.
 	
-		if (toRedact) {
-			api.redactEvent(toRedact, event.event_id)
+			if (redactAndMoveShouldOccurIn) {
+				api.redactEvent(redactAndMoveShouldOccurIn, event.event_id)
 				event.content["m.relates_to"] = undefined
-			api.sendEvent(event.room_id, event.type, {...event.content, body: event.content.body+"\n ~ "+event.sender, formatted_body: event.content.formatted_body ? event.content.formatted_body+"<br> ~ "+event.sender :undefined })
+				api.sendEvent(event.room_id, event.type, {...event.content, body: `${event.content.body}\n ~ ${event.sender}`, formatted_body: event.content.formatted_body ? `${event.content.formatted_body}<br> ~ ${event.sender}` : undefined })
 			}
 		}
 	
@@ -221,8 +221,10 @@ async event => {
 				event
 			)
 		}	
-	retrigger.finishedBridging(event.event_id)
-	await api.ackEvent(event)
+	}
+	if (!event.content["m.relates_to"]) { // Ignore edits since they don't update the timeline on Discord
+		sendEvent.latestSenderPerRoom.set(event.room_id, event.sender)
+	}
 }))
 
 sync.addTemporaryListener(as, "type:m.sticker", guard("m.sticker",

src/web/pug-sync.js

@@ -12,8 +12,8 @@ const walkAST = require("pug-walk")
 const pretty = process.argv.join(" ").includes("test")
 
 const {sync} = require("../passthrough")
-/** @type {import("./auth")} */
-const auth = sync.require("./auth")
+/** @type {import("./web-utils")} */
+const webUtils = sync.require("./web-utils")
 /** @type {import("../js/errors")} */
 const errors = sync.require("../js/errors")
 
@@ -88,8 +88,8 @@ function renderPath(event, path, fragments, locals) {
 			const requiredVars = []
 			const template = compileFile(path, {pretty, plugins: fragmentSelectorPlugins(fragments, requiredVars)})
 			pugCache.set(cacheKey, async (event, locals) => {
-				const session = await auth.useSession(event)
-				const managed = await auth.getManagedGuilds(event)
+				const session = await webUtils.useSession(event)
+				const managed = await webUtils.getManagedGuilds(event)
 				const rel = (to, paramsObject) => {
 					let result = getRelativePath(event.path, to)
 					if (paramsObject) {

src/web/routes/guild-settings.js

@@ -6,8 +6,8 @@ const {defineEventHandler, createError, readValidatedBody, getRequestHeader, set
 
 const {as, db, sync, select, discord} = require("../../passthrough")
 
-/** @type {import("../auth")} */
-const auth = sync.require("../auth")
+/** @type {import("../web-utils")} */
+const webUtils = sync.require("../web-utils")
 /** @type {import("../pug-sync")} */
 const pugSync = sync.require("../pug-sync")
 /** @type {import("../../d2m/actions/set-presence")} */
@@ -56,7 +56,7 @@ function defineToggle(key, inputOptions) {
 		})
 		/** @type {Record<T, string?> & Record<"guild_id", string> & Record<string, unknown>} */ // @ts-ignore
 		const parsedBody = await readValidatedBody(event, bodySchema.parse)
-		const managed = await auth.getManagedGuilds(event)
+		const managed = await webUtils.getManagedGuilds(event)
 		if (!managed.has(parsedBody.guild_id)) throw createError({status: 403, message: "Forbidden", data: "Can't change settings for a guild you don't have Manage Server permissions in"})
 
 		const value = options.transform(parsedBody[key])
@@ -108,7 +108,7 @@ as.router.post("/api/privacy-level", defineToggle("privacy_level", {
 as.router.post("/api/default-roles", defineEventHandler(async event => {
 	const parsedBody = await readValidatedBody(event, schema.defaultRoles.parse)
 
-	const managed = await auth.getManagedGuilds(event)
+	const managed = await webUtils.getManagedGuilds(event)
 	const guildID = parsedBody.guild_id
 	if (!managed.has(guildID)) throw createError({status: 403, message: "Forbidden", data: "Can't change settings for a guild you don't have Manage Server permissions in"})
 
@@ -148,7 +148,7 @@ as.router.post("/api/room-mention-role", defineEventHandler(async event => {
 		channel_id: z.string(),
 		room_mention_role: z.string().regex(/^(?:[0-9]+)?$/)
 	}).parse)
-	const managed = await auth.getManagedGuilds(event)
+	const managed = await webUtils.getManagedGuilds(event)
 	if (!managed.has(body.guild_id)) throw createError({status: 403, message: "Forbidden", data: "Can't change settings for a guild you don't have Manage Server permissions in"})
 	const room = select("channel_room", "room_id", {channel_id: body.channel_id, guild_id: body.guild_id}).get()
 	if (!room) throw createError({status: 404, message: "Linked channel not found"})

src/web/routes/guild.js

@@ -15,8 +15,8 @@ const {discord, as, sync, select, from, db} = require("../../passthrough")
 const pugSync = sync.require("../pug-sync")
 /** @type {import("../../d2m/actions/create-space")} */
 const createSpace = sync.require("../../d2m/actions/create-space")
-/** @type {import("../auth")} */
-const auth = require("../auth")
+/** @type {import("../web-utils")} */
+const webUtils = require("../web-utils")
 /** @type {import("../../discord/utils")} */
 const dUtils = sync.require("../../discord/utils")
 /** @type {import("../../matrix/utils")} */
@@ -178,8 +178,8 @@ function getInviteTargetSpaces(mxid) {
 
 as.router.get("/guild", defineEventHandler(async event => {
 	const {guild_id} = await getValidatedQuery(event, schema.guild.parse)
-	const session = await auth.useSession(event)
-	const managed = await auth.getManagedGuilds(event)
+	const session = await webUtils.useSession(event)
+	const managed = await webUtils.getManagedGuilds(event)
 	const row = from("guild_active").join("guild_space", "guild_id", "left").select("space_id", "privacy_level", "autocreate").where({guild_id}).get()
 	// @ts-ignore
 	const guild = discord.guilds.get(guild_id)
@@ -220,7 +220,7 @@ as.router.get("/explain", defineEventHandler(async event => {
 
 as.router.get("/qr", defineEventHandler(async event => {
 	const {guild_id} = await getValidatedQuery(event, schema.qr.parse)
-	const managed = await auth.getManagedGuilds(event)
+	const managed = await webUtils.getManagedGuilds(event)
 	const row = from("guild_active").join("guild_space", "guild_id", "left").select("space_id", "privacy_level", "autocreate").where({guild_id}).get()
 	// @ts-ignore
 	const guild = discord.guilds.get(guild_id)
@@ -253,7 +253,7 @@ as.router.get("/invite", defineEventHandler(async event => {
 
 as.router.post("/api/invite", defineEventHandler(async event => {
 	const parsedBody = await readValidatedBody(event, schema.invite.parse)
-	const managed = await auth.getManagedGuilds(event)
+	const managed = await webUtils.getManagedGuilds(event)
 	const api = getAPI(event)
 
 	// Check guild ID or nonce

src/web/routes/link.js

@@ -7,8 +7,8 @@ const Ty = require("../../types")
 const DiscordTypes = require("discord-api-types/v10")
 
 const {discord, db, as, sync, select, from} = require("../../passthrough")
-/** @type {import("../auth")} */
-const auth = sync.require("../auth")
+/** @type {import("../web-utils")} */
+const webUtils = sync.require("../web-utils")
 /** @type {import("../../matrix/utils")}*/
 const utils = sync.require("../../matrix/utils")
 /** @type {import("./guild")}*/
@@ -98,8 +98,8 @@ async function validateAndUnbridgeChannel(event, channel_id, guild_id) {
 
 as.router.post("/api/link-space", defineEventHandler(async event => {
 	const parsedBody = await readValidatedBody(event, schema.linkSpace.parse)
-	const session = await auth.useSession(event)
-	const managed = await auth.getManagedGuilds(event)
+	const session = await webUtils.useSession(event)
+	const managed = await webUtils.getManagedGuilds(event)
 	const api = getAPI(event)
 
 	// Check guild ID
@@ -148,7 +148,7 @@ as.router.post("/api/link-space", defineEventHandler(async event => {
 
 as.router.post("/api/link", defineEventHandler(async event => {
 	const parsedBody = await readValidatedBody(event, schema.link.parse)
-	const managed = await auth.getManagedGuilds(event)
+	const managed = await webUtils.getManagedGuilds(event)
 	const api = getAPI(event)
 	const createRoom = getCreateRoom(event)
 	const createSpace = getCreateSpace(event)
@@ -249,7 +249,7 @@ as.router.post("/api/link", defineEventHandler(async event => {
 
 as.router.post("/api/unlink", defineEventHandler(async event => {
 	const {channel_id, guild_id} = await readValidatedBody(event, schema.unlink.parse)
-	const managed = await auth.getManagedGuilds(event)
+	const managed = await webUtils.getManagedGuilds(event)
 
 	// Check guild ID or nonce
 	if (!managed.has(guild_id)) throw createError({status: 403, message: "Forbidden", data: "Can't edit a guild you don't have Manage Server permissions in"})
@@ -266,7 +266,7 @@ as.router.post("/api/unlink", defineEventHandler(async event => {
 
 as.router.post("/api/unlink-space", defineEventHandler(async event => {
 	const {guild_id} = await readValidatedBody(event, schema.unlinkSpace.parse)
-	const managed = await auth.getManagedGuilds(event)
+	const managed = await webUtils.getManagedGuilds(event)
 	const api = getAPI(event)
 	const snow = getSnow(event)
 

src/web/routes/log-in-with-matrix.js

@@ -12,8 +12,8 @@ const {sync} = require("../../passthrough")
 const assert = require("assert").strict
 /** @type {import("../pug-sync")} */
 const pugSync = sync.require("../pug-sync")
-/** @type {import("../auth")} */
-const auth = sync.require("../auth")
+/** @type {import("../web-utils")} */
+const webUtils = sync.require("../web-utils")
 
 const schema = {
 	form: z.object({
@@ -52,12 +52,11 @@ as.router.get("/log-in-with-matrix", defineEventHandler(async event => {
 		return pugSync.render(event, "log-in-with-matrix.pug", {next})
 	}
 
-	const userAgent = getRequestHeader(event, "User-Agent")
-	if (userAgent?.match(/bot|matrix/)) throw createError({status: 400, data: "Sorry URL previewer, you can't have this URL."})
+	webUtils.rejectUrlPreviewer(event)
 
 	if (!validToken.has(token)) return sendRedirect(event, `${reg.ooye.bridge_origin}/log-in-with-matrix`, 302)
 
-	const session = await auth.useSession(event)
+	const session = await webUtils.useSession(event)
 	const mxid = validToken.get(token)
 	assert(mxid)
 	validToken.delete(token)

src/web/routes/oauth.js

@@ -9,8 +9,8 @@ const getRelativePath = require("get-relative-path")
 
 const {as, db, sync} = require("../../passthrough")
 const {id, permissions} = require("../../../addbot")
-/** @type {import("../auth")} */
-const auth = sync.require("../auth")
+/** @type {import("../web-utils")} */
+const webUtils = sync.require("../web-utils")
 const {reg} = require("../../matrix/read-registration")
 
 const redirect_uri = `${reg.ooye.bridge_origin}/oauth`
@@ -53,7 +53,7 @@ function getOauth2Token(event) {
 }
 
 as.router.get("/oauth", defineEventHandler(async event => {
-	const session = await auth.useSession(event)
+	const session = await webUtils.useSession(event)
 	const parsedFirstQuery = await getValidatedQuery(event, schema.first.safeParse)
 	let scope = "guilds"
 

src/web/routes/opt-out.js

@@ -6,10 +6,8 @@ const {defineEventHandler, createError, readValidatedBody, getRequestHeader, set
 
 const {as, db, sync, select, discord} = require("../../passthrough")
 
-/** @type {import("../auth")} */
-const auth = sync.require("../auth")
-/** @type {import("../pug-sync")} */
-const pugSync = sync.require("../pug-sync")
+/** @type {import("../web-utils")} */
+const webUtils = sync.require("../web-utils")
 
 const schema = {
 	optOut: z.object({
@@ -23,7 +21,7 @@ as.router.post("/api/opt-out", defineEventHandler(async event => {
 		throw createError({status: 403, message: "Forbidden", data: "JavaScript is required for the opt-out form."})
 	}
 
-	const session = await auth.useSession(event)
+	const session = await webUtils.useSession(event)
 	if (!session.data.userID) {
 		throw createError({status: 401, message: "Unauthorised", data: "Log in first."})
 	}

src/web/routes/password.js

@@ -4,8 +4,8 @@ const {z} = require("zod")
 const {defineEventHandler, readValidatedBody, sendRedirect} = require("h3")
 const {as, sync} = require("../../passthrough")
 
-/** @type {import("../auth")} */
-const auth = sync.require("../auth")
+/** @type {import("../web-utils")} */
+const webUtils = sync.require("../web-utils")
 
 const schema = {
 	password: z.object({
@@ -15,7 +15,7 @@ const schema = {
 
 as.router.post("/api/password", defineEventHandler(async event => {
 	const {password} = await readValidatedBody(event, schema.password.parse)
-	const session = await auth.useSession(event)
+	const session = await webUtils.useSession(event)
 	await session.update({password})
 	return sendRedirect(event, "../")
 }))

src/web/routes/time.js

@@ -8,6 +8,8 @@ const {z} = require("zod")
 const pugSync = sync.require("../pug-sync")
 /** @type {import("../../discord/time")} */
 const discordTime = sync.require("../../discord/time")
+/** @type {import("../web-utils")} */
+const webUtils = sync.require("../web-utils")
 
 const schema = {
 	time: z.object({
@@ -17,6 +19,7 @@ const schema = {
 }
 
 as.router.get("/time/:timestamp", defineEventHandler(async event => {
+	webUtils.rejectUrlPreviewer(event) // url previewers can't show the local time, making it useless. hiding for everyone's sake
 	const {timestamp} = await getValidatedRouterParams(event, schema.time.parse)
 	const formatOptions = discordTime.getFormatOptions()
 	const text = discordTime.convertDiscordTime(timestamp)
@@ -24,6 +27,7 @@ as.router.get("/time/:timestamp", defineEventHandler(async event => {
 }))
 
 as.router.get("/time/:timestamp/:style", defineEventHandler(async event => {
+	webUtils.rejectUrlPreviewer(event)
 	const {timestamp, style} = await getValidatedRouterParams(event, schema.time.parse)
 	const formatOptions = discordTime.getFormatOptions(style)
 	const text = discordTime.convertDiscordTime(timestamp, style)

src/web/web-utils.js

@@ -1,6 +1,7 @@
 // @ts-check
 
 const h3 = require("h3")
+const {getRequestHeader, createError} = require("h3")
 const {db} = require("../passthrough")
 const {reg} = require("../matrix/read-registration")
 
@@ -29,5 +30,15 @@ function useSession(event) {
 	return h3.useSession(event, {password: reg.as_token, maxAge: 365 * 24 * 60 * 60})
 }
 
+/**
+ * Rejects by throwing createError.
+ * @param {h3.H3Event} event
+ */
+function rejectUrlPreviewer(event) {
+	const userAgent = getRequestHeader(event, "User-Agent")
+	if (userAgent?.match(/bot|matrix|tuwunel/i)) throw createError({status: 400, data: "Sorry URL previewer, you can't have this URL."})
+}
+
 module.exports.getManagedGuilds = getManagedGuilds
 module.exports.useSession = useSession
+module.exports.rejectUrlPreviewer = rejectUrlPreviewer