Relative run mode (#1512)

* inti relative mode

* send imediat update on mode change

* add relative to test

* don't persist offset mode

* add test relative and update calc function

* pass data from ssocket

* add dev guard

* spelling and comments

* show relative in offset overview

* remove comments

* refactor: move totalDelay to _rundown

* update  clear naming and comments

* remove old testing values

apps/server/src/services/timerUtils.ts

@@ -156,6 +156,23 @@ export function getRuntimeOffset(state: RuntimeState): number {
   return startOffset - addedTime - pausedTime + overtime;
 }
 
+/**
+ * Calculates relative offset
+ * should always be calculated after the absolute offset
+ */
+export function getRelativeOffset(state: RuntimeState): number {
+  const { actualStart, plannedStart, offset } = state.runtime;
+  // eslint-disable-next-line no-unused-labels -- dev code path
+  DEV: {
+    // we know actualStart and plannedStart exists as long as a timer is running
+    if (actualStart === null || plannedStart === null) {
+      throw new Error('timerUtils.calculate: actualStart and plannedStart must be set');
+    }
+  }
+  const relativeStartOffset = actualStart - plannedStart;
+  return offset + relativeStartOffset;
+}
+
 /**
  * Calculates the expected end of the rundown
  */
@@ -164,7 +181,7 @@ export function getExpectedEnd(state: RuntimeState): MaybeNumber {
   if (state.runtime.actualStart === null || state.runtime.plannedEnd === null) {
     return null;
   }
-  return state.runtime.plannedEnd - state.runtime.offset + state._timer.totalDelay;
+  return state.runtime.plannedEnd - state.runtime.offset + state._rundown.totalDelay;
 }
 
 /**