The function argument is good enough

d2m/actions/send-message.js

@@ -46,7 +46,10 @@ async function sendMessage(message, guild) {
 		const eventID = await api.sendEvent(roomID, eventType, eventWithoutType, senderMxid, useTimestamp)
 		db.prepare("INSERT INTO event_message (event_id, event_type, event_subtype, message_id, part, source) VALUES (?, ?, ?, ?, ?, 1)").run(eventID, eventType, event.msgtype || null, message.id, eventPart) // source 1 = discord
 
-		eventPart = 1 // TODO: use more intelligent algorithm to determine whether primary or supporting
+		// The primary event is part = 0 and has the most important and distinct information. It is used to provide reply previews, be pinned, and possibly future uses.
+		// The first event is chosen to be the primary part because it is usually the message text content and is more likely to be distinct.
+		// For example, "Reply to 'this meme made me think of you'" is more useful than "Replied to image".
+		eventPart = 1
 		eventIDs.push(eventID)
 	}
 

m2d/actions/add-reaction.js

@@ -19,7 +19,7 @@ async function addReaction(event) {
 	const messageID = select("event_message", "message_id", {event_id: event.content["m.relates_to"].event_id, part: 0}).pluck().get() // 0 = primary
 	if (!messageID) return // Nothing can be done if the parent message was never bridged.
 
-	const key = event.content["m.relates_to"].key // TODO: handle custom text or emoji reactions
+	const key = event.content["m.relates_to"].key
 	const discordPreferredEncoding = emoji.encodeEmoji(key, event.content.shortcode)
 	if (!discordPreferredEncoding) return
 

matrix/file.js

@@ -21,13 +21,11 @@ function _removeExpiryParams(url) {
 }
 
 /**
- * @param {string} path
+ * @param {string} path or full URL if it's not a Discord CDN file
  */
 async function uploadDiscordFileToMxc(path) {
 	let url
 	if (path.startsWith("http")) {
-		// TODO: this is cheating to make seed.js easier. due a refactor or a name change since it's not soley for discord?
-		// possibly could be good to save non-discord external URLs under a user-specified key rather than simply using the url?
 		url = path
 	} else {
 		url = DISCORD_IMAGES_BASE + path