From 18481d9970bb04125badd7ff52a6338116b40422 Mon Sep 17 00:00:00 2001
From: Wolfgang Hottgenroth <wolfgang.hottgenroth@icloud.com>
Date: Thu, 27 Nov 2025 16:48:19 +0100
Subject: [PATCH] hottis modbus relay

---
 apps/abstraction/transformation.py | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/apps/abstraction/transformation.py b/apps/abstraction/transformation.py
index b20bad9..0b49d2f 100644
--- a/apps/abstraction/transformation.py
+++ b/apps/abstraction/transformation.py
@@ -374,6 +374,35 @@ def _transform_relay_shelly_to_abstract(payload: str) -> dict[str, Any]:
     """
     return {"power": payload.strip()}
 
+# ============================================================================
+# HANDLER FUNCTIONS: relay - hottis_modbus technology
+# ============================================================================
+
+def _transform_relay_hottis_modbus_to_vendor(payload: dict[str, Any]) -> str:
+    """Transform abstract relay payload to Hottis Modbus format.
+    
+    Hottis Modbus expects plain text 'on' or 'off' (not JSON).
+    - power: 'on'/'off' -> 'on'/'off' (plain string)
+    
+    Example:
+    - Abstract: {'power': 'on'}
+    - Hottis Modbus: 'on'
+    """
+    power = payload.get("power", "off")
+    return power
+
+
+def _transform_relay_hottis_modbus_to_abstract(payload: str) -> dict[str, Any]:
+    """Transform Hottis Modbus relay payload to abstract format.
+    
+    Hottis Modbus sends plain text 'on' or 'off' (not JSON).
+    - 'on'/'off' -> power: 'on'/'off'
+    
+    Example:
+    - Hottis Modbus: 'on'
+    - Abstract: {'power': 'on'}
+    """
+    return {"power": payload.strip()}
 
 # ============================================================================
 # HANDLER FUNCTIONS: max technology (Homegear MAX!)