From dbe78ad9e74c7f4fe93d63c044e827c97dfc5d75 Mon Sep 17 00:00:00 2001
From: zubiden <19638254+zubiden@users.noreply.github.com>
Date: Tue, 9 Sep 2025 20:26:10 +0200
Subject: [PATCH] Channel: Support direct messages deeplink (#6175)

---
 src/global/actions/api/chats.ts | 17 ++++++++++++++---
 src/util/deepLinkParser.ts      | 11 ++++++++++-
 src/util/deeplink.ts            |  1 +
 3 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/src/global/actions/api/chats.ts b/src/global/actions/api/chats.ts
index 28299968d..fe390012d 100644
--- a/src/global/actions/api/chats.ts
+++ b/src/global/actions/api/chats.ts
@@ -1654,7 +1654,7 @@ addActionHandler('acceptChatInvite', async (global, actions, payload): Promise<v
 addActionHandler('openChatByUsername', async (global, actions, payload): Promise<void> => {
   const {
     username, messageId, commentId, startParam, startAttach, attach, threadId, originalParts,
-    startApp, shouldStartMainApp, mode,
+    startApp, shouldStartMainApp, mode, isDirect,
     text, onChatChanged, choose, ref, timestamp, linkContext,
     tabId = getCurrentTabId(),
   } = payload;
@@ -3433,7 +3433,13 @@ async function openChatByUsername<T extends GlobalState>(
     return;
   }
 
-  const isCurrentChat = currentChat?.usernames?.some((c) => c.username === username);
+  const localChat = selectChatByUsername(global, username);
+  const localDirectChat = isDirect && localChat?.linkedMonoforumId && !localChat.isMonoforum
+    ? selectChat(global, localChat.linkedMonoforumId) : undefined;
+
+  const isCurrentChat = !isDirect
+    ? currentChat?.usernames?.some((c) => c.username === username)
+    : localDirectChat?.id === currentChat?.id;
 
   if (!isCurrentChat) {
     // Open temporary empty chat to make the click response feel faster
@@ -3459,7 +3465,12 @@ async function openChatByUsername<T extends GlobalState>(
     return;
   }
 
-  openChatWithParams(global, actions, chat, {
+  const monoforumChat = isDirect && !chat.isMonoforum && chat.linkedMonoforumId
+    ? selectChat(global, chat.linkedMonoforumId) : undefined;
+
+  const targetChat = (isDirect && monoforumChat) || chat;
+
+  openChatWithParams(global, actions, targetChat, {
     isCurrentChat,
     threadId,
     messageId: channelPostId,
diff --git a/src/util/deepLinkParser.ts b/src/util/deepLinkParser.ts
index 0948056b9..bc9bc736c 100644
--- a/src/util/deepLinkParser.ts
+++ b/src/util/deepLinkParser.ts
@@ -70,6 +70,7 @@ interface PublicUsernameOrBotLink {
   attach?: string;
   text?: string;
   choose?: string;
+  isDirect?: boolean;
 }
 
 interface PrivateChannelLink {
@@ -146,6 +147,10 @@ type PublicMessageLinkBuilderParams = Omit<BuilderParams<PublicMessageLink>, 'is
   single?: string;
 };
 
+type PublicUsernameOrBotLinkBuilderParams = Omit<BuilderParams<PublicUsernameOrBotLink>, 'isDirect'> & {
+  direct?: string;
+};
+
 const ELIGIBLE_HOSTNAMES = new Set(['t.me', 'telegram.me', 'telegram.dog']);
 
 export function isDeepLink(link: string): boolean {
@@ -249,6 +254,7 @@ function parseTgLink(url: URL) {
         attach: queryParams.attach,
         choose: queryParams.choose,
         ref: queryParams.ref,
+        direct: queryParams.direct,
       });
     case 'privateChannelLink': {
       return buildPrivateChannelLink({ channelId: queryParams.channel });
@@ -355,6 +361,7 @@ function parseHttpLink(url: URL) {
         attach: queryParams.attach,
         choose: queryParams.choose,
         ref: queryParams.ref,
+        direct: queryParams.direct,
       });
     case 'privateChannelLink': {
       return buildPrivateChannelLink({ channelId: pathParams[1] });
@@ -605,7 +612,7 @@ function buildTelegramPassportLink(
 }
 
 function buildPublicUsernameOrBotLink(
-  params: BuilderParams<PublicUsernameOrBotLink>,
+  params: PublicUsernameOrBotLinkBuilderParams,
 ): BuilderReturnType<PublicUsernameOrBotLink> {
   const {
     username,
@@ -618,6 +625,7 @@ function buildPublicUsernameOrBotLink(
     appName,
     choose,
     ref,
+    direct,
   } = params;
   if (!username) {
     return undefined;
@@ -637,6 +645,7 @@ function buildPublicUsernameOrBotLink(
     text,
     choose,
     ref,
+    isDirect: direct === '',
   };
 }
 
diff --git a/src/util/deeplink.ts b/src/util/deeplink.ts
index 9f15c4ec9..f53304340 100644
--- a/src/util/deeplink.ts
+++ b/src/util/deeplink.ts
@@ -49,6 +49,7 @@ export const processDeepLink = (url: string, linkContext?: LinkContext): boolean
           attach: parsedLink.attach,
           choose,
           originalParts: [parsedLink.username, parsedLink.appName],
+          isDirect: parsedLink.isDirect,
         });
         return true;
       }