Improve cross-platform group integration

core/tasks/external_chat_support.py

@@ -0,0 +1,73 @@
+from __future__ import annotations
+
+import re
+from typing import Any
+
+from django.db.models import Q
+
+from core.models import ExternalChatLink, PersonIdentifier
+
+
+def channel_variants(service: str, channel: str) -> list[str]:
+    value = str(channel or "").strip()
+    if not value:
+        return []
+    variants = [value]
+    service_key = str(service or "").strip().lower()
+    if service_key == "whatsapp":
+        bare = value.split("@", 1)[0].strip()
+        if bare and bare not in variants:
+            variants.append(bare)
+        direct = f"{bare}@s.whatsapp.net" if bare else ""
+        if direct and direct not in variants:
+            variants.append(direct)
+        group = f"{bare}@g.us" if bare else ""
+        if group and group not in variants:
+            variants.append(group)
+    if service_key == "signal":
+        digits = re.sub(r"[^0-9]", "", value)
+        if digits and digits not in variants:
+            variants.append(digits)
+        if digits:
+            plus = f"+{digits}"
+            if plus not in variants:
+                variants.append(plus)
+    return variants
+
+
+def resolve_external_chat_id(*, user, provider: str, service: str, channel: str) -> str:
+    variants = channel_variants(service, channel)
+    if not variants:
+        return ""
+    person_identifier = (
+        PersonIdentifier.objects.filter(
+            user=user,
+            service=service,
+            identifier__in=variants,
+        )
+        .select_related("person")
+        .order_by("-id")
+        .first()
+    )
+    if person_identifier is None:
+        return ""
+    link = (
+        ExternalChatLink.objects.filter(
+            user=user,
+            provider=provider,
+            enabled=True,
+        )
+        .filter(
+            Q(person_identifier=person_identifier) | Q(person=person_identifier.person)
+        )
+        .order_by("-updated_at", "-id")
+        .first()
+    )
+    return str(getattr(link, "external_chat_id", "") or "").strip()
+
+
+def compact_json_snippet(payload: Any, limit: int = 800) -> str:
+    text = str(payload or "").strip()
+    if len(text) <= limit:
+        return text
+    return text[:limit].rstrip() + "..."