Implement the speedbump

d2m/actions/delete-message.js

@@ -4,21 +4,25 @@ const passthrough = require("../../passthrough")
 const {sync, db, select, from} = passthrough
 /** @type {import("../../matrix/api")} */
 const api = sync.require("../../matrix/api")
+/** @type {import("./speedbump")} */
+const speedbump = sync.require("./speedbump")
 
 /**
  * @param {import("discord-api-types/v10").GatewayMessageDeleteDispatchData} data
  */
 async function deleteMessage(data) {
-	const roomID = select("channel_room", "room_id", {channel_id: data.channel_id}).pluck().get()
-	if (!roomID) return
+	const row = select("channel_room", ["room_id", "speedbump_id", "speedbump_checked"], {channel_id: data.channel_id}).get()
+	if (!row) return
 
 	const eventsToRedact = select("event_message", "event_id", {message_id: data.id}).pluck().all()
 	db.prepare("DELETE FROM message_channel WHERE message_id = ?").run(data.id)
 	db.prepare("DELETE FROM event_message WHERE message_id = ?").run(data.id)
 	for (const eventID of eventsToRedact) {
 		// Unfortunately, we can't specify a sender to do the redaction as, unless we find out that info via the audit logs
-		await api.redactEvent(roomID, eventID)
+		await api.redactEvent(row.room_id, eventID)
 	}
+
+	speedbump.updateCache(data.channel_id, row.speedbump_id, row.speedbump_checked)
 }
 
 /**

d2m/actions/speedbump.js

@@ -0,0 +1,51 @@
+// @ts-check
+
+const DiscordTypes = require("discord-api-types/v10")
+const passthrough = require("../../passthrough")
+const {discord, db} = passthrough
+
+const SPEEDBUMP_SPEED = 4000 // 4 seconds delay
+const SPEEDBUMP_UPDATE_FREQUENCY = 2 * 60 * 60 // 2 hours
+
+/** @type {Set<any>} */
+const KNOWN_BOTS = new Set([
+	"466378653216014359" // PluralKit
+])
+
+/**
+ * Fetch new speedbump data for the channel and put it in the database as cache
+ * @param {string} channelID
+ * @param {string?} speedbumpID
+ * @param {number?} speedbumpChecked
+ */
+async function updateCache(channelID, speedbumpID, speedbumpChecked) {
+	const now = Math.floor(Date.now() / 1000)
+	if (speedbumpChecked && now - speedbumpChecked < SPEEDBUMP_UPDATE_FREQUENCY) return
+	const webhooks = await discord.snow.webhook.getChannelWebhooks(channelID)
+	const found = webhooks.find(b => KNOWN_BOTS.has(b.application_id))?.application_id || null
+	db.prepare("UPDATE channel_room SET speedbump_id = ?, speedbump_checked = ? WHERE channel_id = ?").run(found, now, channelID)
+}
+
+/** @type {Set<string>} set of messageID */
+const bumping = new Set()
+
+/**
+ * Slow down a message. After it passes the speedbump, return whether it's okay or if it's been deleted.
+ * @param {string} messageID
+ */
+async function doSpeedbump(messageID) {
+	bumping.add(messageID)
+	await new Promise(resolve => setTimeout(resolve, SPEEDBUMP_SPEED))
+	return !bumping.delete(messageID)
+}
+
+/**
+ * @param {string} messageID
+ */
+function onMessageDelete(messageID) {
+	bumping.delete(messageID)
+}
+
+module.exports.updateCache = updateCache
+module.exports.doSpeedbump = doSpeedbump
+module.exports.onMessageDelete = onMessageDelete

d2m/discord-client.js

@@ -47,7 +47,16 @@ class DiscordClient {
 		if (listen !== "no") {
 			this.cloud.on("event", message => discordPackets.onPacket(this, message, listen))
 		}
-		this.cloud.on("error", console.error)
+
+		const addEventLogger = (eventName, logName) => {
+			this.cloud.on(eventName, (...args) => {
+				const d = new Date().toISOString().slice(0, 19)
+				console.error(`[${d} Client ${logName}]`, ...args)
+			})
+		}
+		addEventLogger("error", "Error")
+		addEventLogger("disconnected", "Disconnected")
+		addEventLogger("ready", "Ready")
 	}
 }
 

d2m/event-dispatcher.js

@@ -31,6 +31,8 @@ const dUtils = sync.require("../discord/utils")
 const discordCommandHandler = sync.require("../discord/discord-command-handler")
 /** @type {import("../m2d/converters/utils")} */
 const mxUtils = require("../m2d/converters/utils")
+/** @type {import("./actions/speedbump")} */
+const speedbump = sync.require("./actions/speedbump")
 
 /** @type {any} */ // @ts-ignore bad types from semaphore
 const Semaphore = require("@chriscdn/promise-semaphore")
@@ -236,9 +238,12 @@ module.exports = {
 		if (message.author.username === "Deleted User") return // Nothing we can do for deleted users.
 		if (message.webhook_id) {
 			const row = select("webhook", "webhook_id", {webhook_id: message.webhook_id}).pluck().get()
-			if (row) {
-				// The message was sent by the bridge's own webhook on discord. We don't want to reflect this back, so just drop it.
-				return
+			if (row) return // The message was sent by the bridge's own webhook on discord. We don't want to reflect this back, so just drop it.
+		} else {
+			const speedbumpID = select("channel_room", "speedbump_id", {channel_id: message.channel_id}).pluck().get()
+			if (speedbumpID) {
+				const affected = await speedbump.doSpeedbump(message.id)
+				if (affected) return
 			}
 		}
 		const channel = client.channels.get(message.channel_id)
@@ -299,6 +304,7 @@ module.exports = {
 	 * @param {DiscordTypes.GatewayMessageDeleteDispatchData} data
 	 */
 	async onMessageDelete(client, data) {
+		speedbump.onMessageDelete(data.id)
 		await deleteMessage.deleteMessage(data)
 	},
 

db/migrations/0009-add-speedbump-id.sql

@@ -0,0 +1,6 @@
+BEGIN TRANSACTION;
+
+ALTER TABLE channel_room ADD COLUMN speedbump_id TEXT;
+ALTER TABLE channel_room ADD COLUMN speedbump_checked INTEGER;
+
+COMMIT;

db/orm-defs.d.ts

@@ -7,6 +7,8 @@ export type Models = {
 		thread_parent: string | null
 		custom_avatar: string | null
 		last_bridged_pin_timestamp: number | null
+		speedbump_id: string | null
+		speedbump_checked: number | null
 	}
 
 	event_message: {

docs/pluralkit-notetaking.md

@@ -85,7 +85,9 @@ OOYE's speedbump will prevent the edit command appearing at all on Matrix-side,
 
 ## Database schema
 
-TBD
+* channel_room
+	+ speedbump_id - the ID of the webhook that may be proxying in this channel
+	+ speedbump_checked - time in unix seconds when the webhooks were last queried
 
 ## Unsolved problems
 

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

@@ -581,10 +581,6 @@ test("event2message: ordered list start attribute works", async t => {
 			room_id: '!cBxtVRxDlZvSVhJXVK:cadence.moe',
 			sender: '@Milan:tchncs.de',
 			type: 'm.room.message',
-		}, {}, {
-			api: {
-				getStateEvent: async () => ({displayname: "Milan"})
-			}
 		}),
 		{
 			ensureJoined: [],
@@ -2194,7 +2190,7 @@ test("event2message: mentioning events falls back to original link when the chan
 			}
 		}, {}, {
 			api: {
-				/* c8 skip next 3 */
+				/* c8 ignore next 3 */
 				async getEvent() {
 					t.fail("getEvent should not be called because it should quit early due to no channel-guild")
 				}

stdin.js

@@ -17,6 +17,7 @@ const file = sync.require("./matrix/file")
 const sendEvent = sync.require("./m2d/actions/send-event")
 const eventDispatcher = sync.require("./d2m/event-dispatcher")
 const updatePins = sync.require("./d2m/actions/update-pins")
+const speedbump = sync.require("./d2m/actions/speedbump")
 const ks = sync.require("./matrix/kstate")
 const guildID = "112760669178241024"