fix issue with padding that leads to outofbounds-exception #8

app/src/main/java/de/felixnuesse/timedsilence/volumestate/StateGenerator.kt

@@ -110,14 +110,22 @@ class StateGenerator(private var mContext: Context) {
  val end = System.currentTimeMillis()
  Log.e(TAG(), "Endtime: $end")
  Log.e(TAG(), "Diff: ${end-start}ms")
- return padList(linearList)
+ return padSortedList(linearList)
  }
 
- private fun padList(list: ArrayList<VolumeState>): ArrayList<VolumeState> {
+ /**
+ * This function adds padding to the volume state list and returns that padded list.
+ * With padding, we mean that we add volume states filling "gaps" between two volume states,
+ * so that a day is fully covered. It might still contain gaps with the length of 1 minute.
+ *
+ * Important: list needs to be sorted
+ *
+ */
+ private fun padSortedList(list: ArrayList<VolumeState>): ArrayList<VolumeState> {
  val dayStart = DateUtil.getMidnight(mDate).atZone(ZoneId.systemDefault()).toInstant().toEpochMilli()
  val dayEnd = DateUtil.getMidnight(mDate).plusHours(24).atZone(ZoneId.systemDefault()).toInstant().toEpochMilli()
 
-
+ // first, check if the first element is starting at 00:00. Otherwise, pad.
  val first = list.firstOrNull()
 
  if(first == null || first.startTime > dayStart) {
@@ -127,22 +135,26 @@ class StateGenerator(private var mContext: Context) {
  list.add(0, initialVolumeState)
  }
 
+ // If the last element ends on the next day, set the enddate to midnight.
  val last = list.last()
  if(last.endTime > dayEnd) {
  list.remove(last)
  last.endTime = dayEnd
  list.add(last)
  }
 
+ // if the last element ends before midnight, pad it.
  if(last.endTime < dayEnd) {
  val lastVolumeState = VolumeState(defaultVolume)
  lastVolumeState.startTime = last.endTime
  lastVolumeState.endTime = dayEnd
  list.add(lastVolumeState)
  }
 
+ // if we have more elements than one, pad the elements in between.
  if(list.size>1) {
- for (i in 0..<list.size) {
+ // exclude the "last" element, it will always end on midnight.
+ for (i in 0..<list.size-1) {
  val current = list[i].endTime
  val next = list[i+1].startTime