Change sticker URL and stream response

src/m2d/actions/sticker.js

@@ -0,0 +1,40 @@
+// @ts-check
+
+const {Readable} = require("stream")
+const {ReadableStream} = require("stream/web")
+
+const {sync} = require("../../passthrough")
+const sharp = require("sharp")
+/** @type {import("../../matrix/api")} */
+const api = sync.require("../../matrix/api")
+/** @type {import("../../matrix/mreq")} */
+const mreq = sync.require("../../matrix/mreq")
+const streamMimeType = require("stream-mime-type")
+
+const WIDTH = 160
+const HEIGHT = 160
+/**
+ * Downloads the sticker from the web and converts to webp data.
+ * @param {string} mxc a single mxc:// URL
+ * @returns {Promise<ReadableStream>} sticker webp data, or undefined if the downloaded sticker is not valid
+ */
+async function getAndResizeSticker(mxc) {
+	const res = await api.getMedia(mxc)
+	if (res.status !== 200) {
+		const root = await res.json()
+		throw new mreq.MatrixServerError(root, {mxc})
+	}
+
+	const streamIn = Readable.fromWeb(res.body)
+	const { stream, mime } = await streamMimeType.getMimeType(streamIn)
+	const animated = ["image/gif", "image/webp"].includes(mime)
+
+	const transformer = sharp({animated: animated})
+		.resize(WIDTH, HEIGHT, {fit: "inside", background: {r: 0, g: 0, b: 0, alpha: 0}})
+		.webp()
+	stream.pipe(transformer)
+	return Readable.toWeb(transformer)
+}
+
+
+module.exports.getAndResizeSticker = getAndResizeSticker

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

@@ -631,23 +631,10 @@ async function eventToMessage(event, guild, channel, di) {
 	}
 
 	if (event.type === "m.sticker") {
-		content = ""
+		const withoutMxc = mxUtils.makeMxcPublic(event.content.url)
-		let filename = event.content.body
+		assert(withoutMxc)
-		if (event.type === "m.sticker") {
+		const url = `${reg.ooye.bridge_origin}/download/sticker/${withoutMxc}/_.webp`
-			let mimetype
+		content = `[${event.content.body || "\u2800"}](${url})`
-			if (event.content.info?.mimetype?.includes("/")) {
-				mimetype = event.content.info.mimetype
-			} else {
-				const res = await di.api.getMedia(event.content.url, {method: "HEAD"})
-				if (res.status === 200) {
-					mimetype = res.headers.get("content-type")
-				}
-				if (!mimetype) throw new Error(`Server error ${res.status} or missing content-type while detecting sticker mimetype`)
-			}
-			filename += "." + mimetype.split("/")[1]
-		}
-		attachments.push({id: "0", filename})
-		pendingFiles.push({name: filename, mxc: event.content.url})
 
 	} else if (event.type === "org.matrix.msc3381.poll.start") {
 		const pollContent = event.content["org.matrix.msc3381.poll.start"] // just for convenience

src/web/routes/download-matrix.js

@@ -16,6 +16,9 @@ const emojiSheet = sync.require("../../m2d/actions/emoji-sheet")
 /** @type {import("../../m2d/converters/emoji-sheet")} */
 const emojiSheetConverter = sync.require("../../m2d/converters/emoji-sheet")
 
+/** @type {import("../../m2d/actions/sticker")} */
+const sticker = sync.require("../../m2d/actions/sticker")
+
 const schema = {
 	params: z.object({
 		server_name: z.string(),
@@ -23,6 +26,10 @@ const schema = {
 	}),
 	sheet: z.object({
 		e: z.array(z.string()).or(z.string())
+	}),
+	sticker: z.object({
+		server_name: z.string().regex(/^[^/]+$/),
+		media_id: z.string().regex(/^[A-Za-z0-9_-]+$/)
 	})
 }
 
@@ -90,3 +97,14 @@ as.router.get(`/download/sheet`, defineEventHandler(async event => {
 	setResponseHeader(event, "Content-Type", "image/png")
 	return buffer
 }))
+
+as.router.get(`/download/sticker/:server_name/:media_id/_.webp`, defineEventHandler(async event => {
+	const {server_name, media_id} = await getValidatedRouterParams(event, schema.sticker.parse)
+	/** remember that this has no mxc:// protocol in the string */
+	const mxc = server_name + "/" + media_id
+	verifyMediaHash(mxc)
+
+	const stream = await sticker.getAndResizeSticker(`mxc://${mxc}`)
+	setResponseHeader(event, "Content-Type", "image/webp")
+	return stream
+}))