From a7afe7b5700607dbb7a0d84034fee2c3f24e1afc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20H=C3=BCttemann?= <henrik.huettemann@verdigado.com>
Date: Tue, 12 Sep 2023 15:05:39 +0200
Subject: [PATCH] Add members to channel if they posted a message

---
 src/handlers/messages.ts | 80 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 71 insertions(+), 9 deletions(-)

diff --git a/src/handlers/messages.ts b/src/handlers/messages.ts
index 3180ea6..6f8b4ae 100644
--- a/src/handlers/messages.ts
+++ b/src/handlers/messages.ts
@@ -1,8 +1,17 @@
+import { AxiosError } from 'axios'
 import { Entity, entities } from '../Entities'
 import { IdMapping } from '../entity/IdMapping'
 import log from '../helpers/logger'
-import { getMessageId, getRoomId, getUserId, save } from '../helpers/storage'
+import {
+  getMapping,
+  getMappingByMatrixId,
+  getMessageId,
+  getRoomId,
+  getUserId,
+  save,
+} from '../helpers/storage'
 import { axios, formatUserSessionOptions } from '../helpers/synapse'
+import { acceptInvitation, inviteMember } from './rooms'
 
 const applicationServiceToken = process.env.AS_TOKEN || ''
 if (!applicationServiceToken) {
@@ -134,13 +143,66 @@ export async function handle(rcMessage: RcMessage): Promise<void> {
     }
   }
 
-  const event_id = await createMessage(
-    matrixMessage,
-    room_id,
-    user_id,
-    ts,
-    rcMessage._id
-  )
+  try {
+    const event_id = await createMessage(
+      matrixMessage,
+      room_id,
+      user_id,
+      ts,
+      rcMessage._id
+    )
+    createMapping(rcMessage._id, event_id)
+  } catch (error) {
+    if (
+      error instanceof AxiosError &&
+      error.response &&
+      error.response.data.errcode === 'M_FORBIDDEN' &&
+      error.response.data.error === `User ${user_id} not in room ${room_id}`
+    ) {
+      log.info(error.response.data.error + ', adding.')
 
-  createMapping(rcMessage._id, event_id)
+      const userMapping = await getMapping(
+        rcMessage.u._id,
+        entities[Entity.Users].mappingType
+      )
+      if (!userMapping || !userMapping.matrixId || !userMapping.accessToken) {
+        log.warn(`Could not determine joining user, skipping.`, rcMessage)
+        return
+      }
+
+      // Get room creator session or use empty axios options
+      let userSessionOptions = {}
+      const roomCreatorId = (
+        await axios.get(`/_synapse/admin/v1/rooms/${room_id}`)
+      ).data.creator
+      if (!roomCreatorId) {
+        log.warn(
+          `Could not determine room creator for room ${room_id}, using admin credentials.`
+        )
+      } else {
+        const creatorMapping = await getMappingByMatrixId(roomCreatorId)
+        if (!creatorMapping?.accessToken) {
+          log.warn(`Could not access token for ${roomCreatorId}, skipping.`)
+          return
+        }
+        userSessionOptions = formatUserSessionOptions(
+          creatorMapping.accessToken
+        )
+      }
+
+      await inviteMember(userMapping.matrixId, room_id, userSessionOptions)
+      await acceptInvitation(userMapping, room_id)
+
+      const event_id = await createMessage(
+        matrixMessage,
+        room_id,
+        user_id,
+        ts,
+        rcMessage._id
+      )
+      createMapping(rcMessage._id, event_id)
+    } else {
+      throw error
+    }
+  }
 }