Fix repetition angle handling for single-value list

app/src/main/java/com/laseroptek/raman/ui/screens/home/HomeScreen.kt

@@ -304,7 +304,7 @@ fun HomeScreen(
                     pulseType = pulseType,
                     handPieceType = handPiece.type,
                     type = LaserStatusType.REPETITION,
-                    angle = if (pulseType == 0 || repetitionList.size < 2) 0f else repetitionAngle,
+                    angle = if (pulseType == 0 || repetitionList.isEmpty()) 0f else repetitionAngle,
                     onChange = { angle ->
                         if (handPiece.type == 0) {
                             Toast.makeText(
@@ -315,7 +315,7 @@ fun HomeScreen(
                             return@LaserControlView
                         }
 
-                        if (pulseType == 0 || repetitionList.size < 2) {
+                        if (pulseType == 0 || repetitionList.isEmpty()) {
                             //Toast.makeText(context, "Single pulse type (0 Hz)", Toast.LENGTH_SHORT).show()
                         } else {
                             mainViewModel.onChangeRepetition(angle)
@@ -332,7 +332,7 @@ fun HomeScreen(
                             return@LaserControlView
                         }
 
-                        if (pulseType == 0 || repetitionList.size < 2) {
+                        if (pulseType == 0 || repetitionList.isEmpty()) {
                             //Toast.makeText(context, "Single pulse type (0 Hz)", Toast.LENGTH_SHORT).show()
                         } else {
                             //mainViewModel.onClickRepetition(state)

app/src/main/java/com/laseroptek/raman/ui/screens/main/MainViewModel.kt

@@ -2130,11 +2130,10 @@ class MainViewModel @Inject constructor(
         } else {
             0f
         }
-        val repetitionAngle = if (newRepetitionList.isNotEmpty()) {
-            repetitionStep.stepToDegree(totalSteps = newRepetitionList.size)
-        } else {
-            0f
-        }
+        val repetitionAngle = repetitionIndexToAngle(
+            index = repetitionStep,
+            totalSteps = newRepetitionList.size,
+        )
 
         Timber.d("pulseStep: ${pulseStep} fluenceStep: ${fluenceStep} repetitionStep: ${repetitionStep}")
 
@@ -2178,23 +2177,21 @@ class MainViewModel @Inject constructor(
             setRepetitionList(newRepetitionList)
         }
 
-        // Smartly preserve Repetition Angle
-        // 4. Check if the old repetition value exists in the new list.
-        val oldRepetitionIndex = if (currentRepetitionValue != null) {
-            newRepetitionList.indexOf(currentRepetitionValue)
-        } else {
-            -1
-        }
+        // 4. Resolve and apply repetition by value (not by old angle/index).
+        val targetRepetition = currentRepetitionValue ?: 0f
+        val resolvedRepetition = newRepetitionList.minByOrNull { abs(it - targetRepetition) } ?: 0f
+        val resolvedRepetitionIndex = newRepetitionList.indexOf(resolvedRepetition).takeIf { it >= 0 } ?: 0
 
-        if (oldRepetitionIndex != -1) {
-            // If the old value exists, set the slider to that position.
-            val preservedAngle = oldRepetitionIndex.stepToDegree(totalSteps = newRepetitionList.size)
-            setRepetitionAngle(preservedAngle)
-            Timber.d("Repetition value $currentRepetitionValue preserved at new angle $preservedAngle.")
+        if (newRepetitionList.isNotEmpty()) {
+            val resolvedRepetitionAngle = repetitionIndexToAngle(
+                index = resolvedRepetitionIndex,
+                totalSteps = newRepetitionList.size,
+            )
+            setRepetitionAngle(resolvedRepetitionAngle)
+            Timber.d("Resolved repetition by value: old=$currentRepetitionValue, new=$resolvedRepetition, angle=$resolvedRepetitionAngle")
         } else {
-            // If it doesn't exist, THEN reset the slider to the beginning.
             setRepetitionAngle(0f)
-            Timber.d("Repetition value $currentRepetitionValue not supported in new list. Resetting angle.")
+            Timber.d("Repetition list is empty. Resetting repetition angle to 0f.")
         }
 
         // 5. Conditionally reset the fluence angle slider if needed
@@ -2301,8 +2298,12 @@ class MainViewModel @Inject constructor(
 
     fun onChangeRepetition(angle: Float) {
         // This logic is simple and has no complex dependencies, so it can remain as is.
-        if (angle != repetitionAngle.value) {
-            setRepetitionAngle(angle)
+        val normalizedAngle = repetitionIndexToAngle(
+            index = angle.degreeToStep(totalSteps = repetitionList.value.size),
+            totalSteps = repetitionList.value.size,
+        )
+        if (normalizedAngle != repetitionAngle.value) {
+            setRepetitionAngle(normalizedAngle)
         }
         setSelectedPresetIndex(0)
     }
@@ -2313,12 +2314,23 @@ class MainViewModel @Inject constructor(
         val newStep = if (state == UpDownState.Up) currentStep + 1 else currentStep - 1
 
         if (newStep in repetitionList.value.indices) {
-            val newRepetitionAngle = newStep.stepToDegree(totalSteps = repetitionList.value.size)
+            val newRepetitionAngle = repetitionIndexToAngle(
+                index = newStep,
+                totalSteps = repetitionList.value.size,
+            )
             setRepetitionAngle(newRepetitionAngle)
             setSelectedPresetIndex(0)
         }
     }
 
+    private fun repetitionIndexToAngle(index: Int, totalSteps: Int): Float {
+        return when {
+            totalSteps <= 0 -> 0f
+            totalSteps == 1 -> 270f
+            else -> index.stepToDegree(totalSteps = totalSteps)
+        }
+    }
+
     /**
      * Perform all heavy I/O in a single background block.
      * This prevents the "Skipped frames" caused by 30+ sequential bridge calls