From 0fdee610ed5c189337ec193f97b5cd2906bdbfcf Mon Sep 17 00:00:00 2001
From: Lars <Lars@stommer.de>
Date: Sat, 16 May 2026 08:09:24 +0200
Subject: [PATCH] Enhance section movement validation in
 TrainingUnitSectionsEditor

- Added a new check to prevent section movement across slots that crosses the boundary between 'parallel' and 'whole_group' phases, improving the logic for section management and ensuring valid operations during edits.
---
 .../components/TrainingUnitSectionsEditor.jsx    | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/frontend/src/components/TrainingUnitSectionsEditor.jsx b/frontend/src/components/TrainingUnitSectionsEditor.jsx
index e7fa968..99b4807 100644
--- a/frontend/src/components/TrainingUnitSectionsEditor.jsx
+++ b/frontend/src/components/TrainingUnitSectionsEditor.jsx
@@ -928,9 +928,23 @@ export default function TrainingUnitSectionsEditor({
       }
     }
 
+    let crossesParallelWholePlanBoundary = false
     if (
       enableParallelPhaseControls &&
-      (insertBeforeIdx === fromSi || insertBeforeIdx === fromSi + 1)
+      insertBeforeIdx >= 0 &&
+      insertBeforeIdx < list.length
+    ) {
+      const fromK = list[fromSi]?.planLoc?.phaseKind
+      const toK = list[insertBeforeIdx]?.planLoc?.phaseKind
+      crossesParallelWholePlanBoundary =
+        (fromK === 'parallel' && toK === 'whole_group') ||
+        (fromK === 'whole_group' && toK === 'parallel')
+    }
+
+    if (
+      enableParallelPhaseControls &&
+      (insertBeforeIdx === fromSi || insertBeforeIdx === fromSi + 1) &&
+      !crossesParallelWholePlanBoundary
     ) {
       return
     }