updates Mar6

app/services/whatsapp_service.py

@@ -0,0 +1,36 @@
+import httpx
+import hashlib
+import hmac
+import logging
+
+logger = logging.getLogger(__name__)
+
+_META_API = "https://graph.facebook.com/v19.0"
+
+
+async def send_message(phone_number_id: str, to: str, text: str, access_token: str) -> bool:
+    try:
+        async with httpx.AsyncClient(timeout=10) as client:
+            r = await client.post(
+                f"{_META_API}/{phone_number_id}/messages",
+                headers={"Authorization": f"Bearer {access_token}"},
+                json={
+                    "messaging_product": "whatsapp",
+                    "to": to,
+                    "type": "text",
+                    "text": {"body": text},
+                },
+            )
+            return r.status_code == 200
+    except Exception as e:
+        logger.error(f"WhatsApp send error: {e}")
+        return False
+
+
+def verify_signature(payload: bytes, signature: str, app_secret: str) -> bool:
+    expected = "sha256=" + hmac.new(
+        app_secret.encode("utf-8"),
+        payload,
+        hashlib.sha256,
+    ).hexdigest()
+    return hmac.compare_digest(expected, signature)