From 541c5e1eb524e50c4bbe319e995a9718df4a37a7 Mon Sep 17 00:00:00 2001
From: Cadence Ember <cadence@disroot.org>
Date: Sun, 21 Jul 2024 14:56:58 +1200
Subject: [PATCH] Add include_user_id_in_mxid setting

---
 d2m/converters/user-to-mxid.js      | 5 +++++
 d2m/converters/user-to-mxid.test.js | 8 ++++++++
 registration.example.yaml           | 1 +
 types.d.ts                          | 1 +
 4 files changed, 15 insertions(+)

diff --git a/d2m/converters/user-to-mxid.js b/d2m/converters/user-to-mxid.js
index 6b3bbbd3..97b655eb 100644
--- a/d2m/converters/user-to-mxid.js
+++ b/d2m/converters/user-to-mxid.js
@@ -1,6 +1,7 @@
 // @ts-check
 
 const assert = require("assert")
+const registration = require("../../matrix/read-registration")
 
 const passthrough = require("../../passthrough")
 const {select} = passthrough
@@ -24,6 +25,10 @@ function downcaseUsername(user) {
 		.replace(/[^a-z0-9._=/-]*/g, "")
 		// remove leading and trailing dashes and underscores...
 		.replace(/(?:^[_-]*|[_-]*$)/g, "")
+	// If requested, also make the Discord user ID part of the username
+	if (registration.ooye.include_user_id_in_mxid) {
+		downcased = user.id + "_" + downcased
+	}
 	// The new length must be at least 2 characters (in other words, it should have some content)
 	if (downcased.length < 2) {
 		downcased = user.id
diff --git a/d2m/converters/user-to-mxid.test.js b/d2m/converters/user-to-mxid.test.js
index b080115f..45762057 100644
--- a/d2m/converters/user-to-mxid.test.js
+++ b/d2m/converters/user-to-mxid.test.js
@@ -44,3 +44,11 @@ test("user2name: uses ID when name has only disallowed characters", t => {
 test("user2name: works on special user", t => {
 	t.equal(userToSimName(data.user.clyde_ai), "clyde_ai")
 })
+
+test("user2name: includes ID if requested in config", t => {
+	const reg = require("../../matrix/read-registration")
+	reg.ooye.include_user_id_in_mxid = true
+	t.equal(userToSimName({username: "Harry Styles!", discriminator: "0001", id: "123456"}), "123456_harry_styles")
+   t.equal(userToSimName({username: "f***", discriminator: "0001", id: "123456"}), "123456_f")
+	reg.ooye.include_user_id_in_mxid = false
+})
diff --git a/registration.example.yaml b/registration.example.yaml
index dd217db3..d38f5ae3 100644
--- a/registration.example.yaml
+++ b/registration.example.yaml
@@ -19,6 +19,7 @@ ooye:
   server_name: [the part after the colon in your matrix id, like cadence.moe]
   server_origin: [the full protocol and domain of your actual matrix server's location, with no trailing slash, like https://matrix.cadence.moe]
   content_length_workaround: false
+  include_user_id_in_mxid: false
   invite:
     # uncomment this to auto-invite the named user to newly created spaces and mark them as admin (PL 100) everywhere
     # - '@cadence:cadence.moe'
diff --git a/types.d.ts b/types.d.ts
index 68430d93..60368671 100644
--- a/types.d.ts
+++ b/types.d.ts
@@ -22,6 +22,7 @@ export type AppServiceRegistrationConfig = {
 		server_name: string
 		server_origin: string
 		content_length_workaround: boolean
+		include_user_id_in_mxid: boolean
 		invite: string[]
 	}
 	old_bridge?: {