From ecc7674422ebfba0963c66f16ac31dd7c4e8b7df Mon Sep 17 00:00:00 2001
From: Travis Ralston <travpc@gmail.com>
Date: Thu, 5 Mar 2020 15:38:09 -0700
Subject: [PATCH] Add optional reporting of invites that won't be accepted

---
 config/default.yaml |  5 +++++
 src/config.ts       |  2 ++
 src/index.ts        | 19 +++++++++++++++++--
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/config/default.yaml b/config/default.yaml
index eca8f2d..1f43d3c 100644
--- a/config/default.yaml
+++ b/config/default.yaml
@@ -29,6 +29,11 @@ autojoinOnlyIfManager: true
 # the bot to new rooms.
 acceptInvitesFromGroup: '+example:example.org'
 
+# If the bot is invited to a room and it won't accept the invite (due to the
+# conditions above), report it to the management room. Defaults to disabled (no
+# reporting).
+recordIgnoredInvites: false
+
 # The room ID where people can use the bot. The bot has no access controls, so
 # anyone in this room can use the bot - secure your room!
 # This should be a room alias or room ID - not a matrix.to URL.
diff --git a/src/config.ts b/src/config.ts
index b1a5668..4ade875 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -28,6 +28,7 @@ interface IConfig {
     dataPath: string;
     acceptInvitesFromGroup: string;
     autojoinOnlyIfManager: boolean;
+    recordIgnoredInvites: boolean;
     managementRoom: string;
     verboseLogging: boolean;
     logLevel: "DEBUG" | "INFO" | "WARN" | "ERROR";
@@ -68,6 +69,7 @@ const defaultConfig: IConfig = {
     dataPath: "/data/storage",
     acceptInvitesFromGroup: '+example:example.org',
     autojoinOnlyIfManager: false,
+    recordIgnoredInvites: false,
     managementRoom: "!noop:example.org",
     verboseLogging: false,
     logLevel: "INFO",
diff --git a/src/index.ts b/src/index.ts
index 389cee3..69fcd8b 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -30,6 +30,7 @@ import { Mjolnir } from "./Mjolnir";
 import { logMessage } from "./LogProxy";
 import { MembershipEvent } from "matrix-bot-sdk/lib/models/events/MembershipEvent";
 import { BanListServer } from "./server/BanListServer";
+import * as htmlEscape from "escape-html";
 
 config.RUNTIME = {client: null};
 
@@ -54,13 +55,27 @@ LogService.info("index", "Starting bot...");
     client.on("room.invite", async (roomId: string, inviteEvent: any) => {
         const membershipEvent = new MembershipEvent(inviteEvent);
 
+        const reportInvite = async () => {
+            if (!config.recordIgnoredInvites) return; // Nothing to do
+
+            await client.sendMessage(config.managementRoom, {
+                msgtype: "m.text",
+                body: `${membershipEvent.sender} has invited me to ${roomId} but the config prevents me from accepting the invitation. `
+                    + `If you would like this room protected, use "!mjolnir rooms add ${roomId}" so I can accept the invite.`,
+                format: "org.matrix.custom.html",
+                formatted_body: `${htmlEscape(membershipEvent.sender)} has invited me to ${htmlEscape(roomId)} but the config prevents me from `
+                    + `accepting the invitation. If you would like this room protected, use <code>!mjolnir rooms add ${htmlEscape(roomId)}</code> `
+                    + `so I can accept the invite.`,
+            });
+        };
+
         if (config.autojoinOnlyIfManager) {
             const managers = await client.getJoinedRoomMembers(config.managementRoom);
-            if (!managers.includes(membershipEvent.sender)) return; // ignore invite
+            if (!managers.includes(membershipEvent.sender)) return reportInvite(); // ignore invite
         } else {
             const groupMembers = await client.unstableApis.getGroupUsers(config.acceptInvitesFromGroup);
             const userIds = groupMembers.map(m => m.user_id);
-            if (!userIds.includes(membershipEvent.sender)) return; // ignore invite
+            if (!userIds.includes(membershipEvent.sender)) return reportInvite(); // ignore invite
         }
 
         return client.joinRoom(roomId);