From f25f147fc3ee519dbc27dbdce1388a7b027bab1d Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Sat, 4 Apr 2026 03:57:51 +0100
Subject: [PATCH] refactor(whatsapp): move legacy group session detection into
 contract surface

---
 extensions/whatsapp/contract-surfaces.ts |  2 ++
 src/config/sessions/group.ts             | 20 --------------------
 2 files changed, 2 insertions(+), 20 deletions(-)

diff --git a/extensions/whatsapp/contract-surfaces.ts b/extensions/whatsapp/contract-surfaces.ts
index 421fd8d6ac4..8ae1451fb40 100644
--- a/extensions/whatsapp/contract-surfaces.ts
+++ b/extensions/whatsapp/contract-surfaces.ts
@@ -12,6 +12,8 @@ export const unsupportedSecretRefSurfacePatterns = [
   "channels.whatsapp.accounts.*.creds.json",
 ] as const;
 
+export { resolveLegacyGroupSessionKey } from "./src/group-session-contract.js";
+
 export function collectUnsupportedSecretRefConfigCandidates(
   raw: unknown,
 ): UnsupportedSecretRefConfigCandidate[] {
diff --git a/src/config/sessions/group.ts b/src/config/sessions/group.ts
index 478525ff7e4..d0fc59fbc93 100644
--- a/src/config/sessions/group.ts
+++ b/src/config/sessions/group.ts
@@ -10,15 +10,6 @@ type LegacyGroupSessionSurface = {
   resolveLegacyGroupSessionKey?: (ctx: MsgContext) => GroupKeyResolution | null;
 };
 
-function resolveLegacyWhatsAppGroupId(from: string): string | null {
-  const candidate = from.trim().replace(/^whatsapp:/i, "");
-  if (!candidate.toLowerCase().endsWith("@g.us")) {
-    return null;
-  }
-  const localPart = candidate.slice(0, candidate.length - "@g.us".length);
-  return /^[0-9]+(-[0-9]+)*$/i.test(localPart) ? `${localPart}@g.us` : null;
-}
-
 function resolveLegacyGroupSessionKey(ctx: MsgContext): GroupKeyResolution | null {
   for (const surface of getBundledChannelContractSurfaces() as LegacyGroupSessionSurface[]) {
     const resolved = surface.resolveLegacyGroupSessionKey?.(ctx);
@@ -80,7 +71,6 @@ export function resolveGroupSessionKey(ctx: MsgContext): GroupKeyResolution | nu
   const chatType = ctx.ChatType?.trim().toLowerCase();
   const normalizedChatType =
     chatType === "channel" ? "channel" : chatType === "group" ? "group" : undefined;
-  const legacyWhatsAppGroupId = resolveLegacyWhatsAppGroupId(from);
 
   const legacyResolution = resolveLegacyGroupSessionKey(ctx);
   const looksLikeGroup =
@@ -88,7 +78,6 @@ export function resolveGroupSessionKey(ctx: MsgContext): GroupKeyResolution | nu
     normalizedChatType === "channel" ||
     from.includes(":group:") ||
     from.includes(":channel:") ||
-    legacyWhatsAppGroupId !== null ||
     legacyResolution !== null;
   if (!looksLikeGroup) {
     return null;
@@ -104,15 +93,6 @@ export function resolveGroupSessionKey(ctx: MsgContext): GroupKeyResolution | nu
     return legacyResolution;
   }
 
-  if (!headIsSurface && legacyWhatsAppGroupId) {
-    return {
-      key: `whatsapp:group:${legacyWhatsAppGroupId}`,
-      channel: "whatsapp",
-      id: legacyWhatsAppGroupId,
-      chatType: "group",
-    };
-  }
-
   const provider = headIsSurface ? head : (providerHint ?? legacyResolution?.channel);
   if (!provider) {
     return null;