From 56ab82cabd4ecc97f1b62cf2b51ba604b805d0bf Mon Sep 17 00:00:00 2001
From: Tulir Asokan <tulir@maunium.net>
Date: Thu, 30 Nov 2017 21:38:55 +0200
Subject: [PATCH] Send channel messages as AS bot if sender is unknown

---
 src/app.js             |  7 +++++++
 src/portal.js          |  1 +
 src/telegram-peer.js   | 20 +++++++++++++-------
 src/telegram-puppet.js |  5 +++--
 4 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/src/app.js b/src/app.js
index 75ae7033..93ad905e 100644
--- a/src/app.js
+++ b/src/app.js
@@ -34,6 +34,7 @@ class MautrixTelegram {
 	 */
 	constructor(config) {
 		this.config = config
+		this.channelTelegramSender = new TelegramUser(this, -1)
 
 		/**
 		 * MXID -> {@link MatrixUser} cache.
@@ -142,6 +143,9 @@ class MautrixTelegram {
 	 * @returns {Intent}    The Matrix puppet intent for the given Telegram user.
 	 */
 	getIntentForTelegramUser(id) {
+		if (id === -1) {
+			return this.botIntent
+		}
 		return this.bridge.getIntentFromLocalpart(this.getUsernameForTelegramUser(id))
 	}
 
@@ -282,6 +286,9 @@ class MautrixTelegram {
 	 * @returns {TelegramUser} The TelegramUser object.
 	 */
 	async getTelegramUser(id, { createIfNotFound = true } = {}) {
+		if (id === -1) {
+			return this.channelTelegramSender
+		}
 		// TODO remove this after bugs are fixed
 		if (isNaN(parseInt(id, 10))) {
 			const err = new Error("Fatal: non-int Telegram user ID")
diff --git a/src/portal.js b/src/portal.js
index ec37525d..ed93760e 100644
--- a/src/portal.js
+++ b/src/portal.js
@@ -210,6 +210,7 @@ class Portal {
 				console.error(err.stack)
 			}
 		}
+
 		const sender = await this.app.getTelegramUser(evt.from)
 		await sender.intent.sendTyping(this.roomID, false)
 
diff --git a/src/telegram-peer.js b/src/telegram-peer.js
index 0c1fa1d5..3314df0b 100644
--- a/src/telegram-peer.js
+++ b/src/telegram-peer.js
@@ -137,13 +137,19 @@ class TelegramPeer {
 				channel: this.toInputObject(),
 			})
 			info = info.chats[0]
-			const participants = await telegramPOV.client("channels.getParticipants", {
-				channel: this.toInputObject(),
-				filter: { _: "channelParticipantsRecent" },
-				offset: 0,
-				limit: 1000,
-			})
-			users = participants.users
+			try {
+				const participants = await telegramPOV.client("channels.getParticipants", {
+					channel: this.toInputObject(),
+					filter: { _: "channelParticipantsRecent" },
+					offset: 0,
+					limit: 1000,
+				})
+				users = participants.users
+			} catch (err) {
+				// Getting channel participants apparently requires admin.
+				// TODO figure out what to do about that ^
+				users = []
+			}
 			break
 		default:
 			throw new Error(`Unknown peer type ${this.type}`)
diff --git a/src/telegram-puppet.js b/src/telegram-puppet.js
index daf96e1e..d333b65b 100644
--- a/src/telegram-puppet.js
+++ b/src/telegram-puppet.js
@@ -305,9 +305,11 @@ class TelegramPuppet {
 			from = update.from_id
 			break
 		case "updateNewChannelMessage":
+			// TODO figure out how channel message signing works
+			from = -1
 		case "updateNewMessage":
 			update = update.message // Message defined at message#90dddc11 in layer 71
-			from = update.from_id
+			from = update.from_id || from
 			to = TelegramPeer.fromTelegramData(update.to_id, update.from_id, this.userID)
 			break
 
@@ -317,7 +319,6 @@ class TelegramPuppet {
 			return
 		}
 
-		console.log(update)
 		portal = await this.app.getPortalByPeer(to)
 
 		if (update._ === "messageService") {