comboctl-main: Fix computeShortRTButtonPress() cyclic quantity bug

Signed-off-by: Carlos Rafael Giani <crg7475@mailbox.org>

pump/combov2/comboctl/src/commonMain/kotlin/info/nightscout/comboctl/main/RTNavigation.kt

@@ -1045,10 +1045,17 @@ internal fun computeShortRTButtonPress(
         require(stepSize > 0)
         val distance = (targetQuantity - currentQuantity).absoluteValue
         if (cyclicQuantityRange != null) {
+            // With a cyclic quantity, if the absolute distance between
+            // quantities exceeds half of that range, we have the option
+            // to change the quantity in the opposite direction which
+            // requires fewer button presses. For example, if the range
+            // is 60, and the absolute distance is 40, we'd normally have
+            // to press a button 40 times to get to the target quantity.
+            // But since cyclic quantities wrap around, we can instead
+            // press the opposite button 60-40 = 20 times to also get
+            // to the target quantity.
             if (distance > (cyclicQuantityRange / 2)) {
-                val firstPart = (cyclicQuantityRange - targetQuantity)
+                numNeededShortRTButtonPresses = computeNumSteps(stepSize, cyclicQuantityRange - distance)
-                val secondPart = currentQuantity - 0
-                numNeededShortRTButtonPresses = computeNumSteps(stepSize, firstPart + secondPart)
                 shortRTButtonToPress = if (targetQuantity < currentQuantity) incrementButton else decrementButton
             } else {
                 numNeededShortRTButtonPresses = computeNumSteps(stepSize, distance)

pump/combov2/comboctl/src/jvmTest/kotlin/info/nightscout/comboctl/main/RTNavigationTest.kt

@@ -274,6 +274,19 @@ class RTNavigationTest {
         )
         assertEquals(Pair(((60 - 50) + (10 - 0)) / 1, RTNavigationButton.DOWN), result)
 
+        // Another cyclic quantity range test with a wrap around,
+        // this time from the other direction (wrapping around
+        // from quantity 58 to target quantity 1).
+        result = computeShortRTButtonPress(
+            currentQuantity = 58,
+            targetQuantity = 1,
+            cyclicQuantityRange = 60,
+            incrementSteps = arrayOf(Pair(0, 1)),
+            incrementButton = RTNavigationButton.UP,
+            decrementButton = RTNavigationButton.DOWN
+        )
+        assertEquals(Pair(3, RTNavigationButton.UP), result)
+
         // Additional test to check that cyclic ranges are handled correctly
         // even if currentQuantity is slightly higher than targetQuantity. This
         // verifies that the computation does not produce negative distances.