Timezone aware scheduling of Alarms

app/src/main/kotlin/org/fossify/clock/activities/ReminderActivity.kt

@@ -23,6 +23,7 @@ import org.fossify.commons.helpers.MINUTE_SECONDS
 import org.fossify.commons.helpers.SILENT
 import org.fossify.commons.helpers.isOreoMr1Plus
 import org.fossify.commons.helpers.isOreoPlus
+import java.util.Calendar
 
 class ReminderActivity : SimpleActivity() {
     companion object {
@@ -267,23 +268,23 @@ class ReminderActivity : SimpleActivity() {
     private fun snoozeAlarm(overrideSnoozeDuration: Int? = null) {
         destroyEffects()
         if (overrideSnoozeDuration != null) {
-            setupAlarmClock(alarm!!, overrideSnoozeDuration * MINUTE_SECONDS)
-            wasAlarmSnoozed = true
-            finishActivity()
+            snoozeAlarm { add(Calendar.MINUTE, overrideSnoozeDuration) }
         } else if (config.useSameSnooze) {
-            setupAlarmClock(alarm!!, config.snoozeTime * MINUTE_SECONDS)
-            wasAlarmSnoozed = true
-            finishActivity()
+            snoozeAlarm { add(Calendar.MINUTE, config.snoozeTime) }
         } else {
             showPickSecondsDialog(config.snoozeTime * MINUTE_SECONDS, true, cancelCallback = { finishActivity() }) {
                 config.snoozeTime = it / MINUTE_SECONDS
-                setupAlarmClock(alarm!!, it)
-                wasAlarmSnoozed = true
-                finishActivity()
+                snoozeAlarm { add(Calendar.SECOND, it) }
             }
         }
     }
 
+    private fun snoozeAlarm(block: Calendar.() -> Unit) {
+        setupAlarmClock(alarm!!, block.run { Calendar.getInstance() })
+        wasAlarmSnoozed = true
+        finishActivity()
+    }
+
     private fun finishActivity() {
         if (!wasAlarmSnoozed && alarm != null) {
             cancelAlarmClock(alarm!!)

app/src/main/kotlin/org/fossify/clock/activities/SnoozeReminderActivity.kt

@@ -9,6 +9,7 @@ import org.fossify.clock.extensions.setupAlarmClock
 import org.fossify.clock.helpers.ALARM_ID
 import org.fossify.commons.extensions.showPickSecondsDialog
 import org.fossify.commons.helpers.MINUTE_SECONDS
+import java.util.Calendar
 
 class SnoozeReminderActivity : AppCompatActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -18,7 +19,7 @@ class SnoozeReminderActivity : AppCompatActivity() {
         hideNotification(id)
         showPickSecondsDialog(config.snoozeTime * MINUTE_SECONDS, true, cancelCallback = { dialogCancelled() }) {
             config.snoozeTime = it / MINUTE_SECONDS
-            setupAlarmClock(alarm, it)
+            setupAlarmClock(alarm, Calendar.getInstance().apply { add(Calendar.SECOND, it) })
             finishActivity()
         }
     }

app/src/main/kotlin/org/fossify/clock/extensions/Context.kt

@@ -100,40 +100,13 @@ fun Context.createNewTimer(): Timer {
 }
 
 fun Context.scheduleNextAlarm(alarm: Alarm, showToast: Boolean) {
-    val calendar = Calendar.getInstance()
-    calendar.firstDayOfWeek = Calendar.MONDAY
-    val currentTimeInMinutes = getCurrentDayMinutes()
+    val triggerTime = getTimeOfNextAlarm(alarm.timeInMinutes, alarm.days) ?: return
+    setupAlarmClock(alarm, triggerTime)
 
-    if (alarm.days == TODAY_BIT) {
-        val triggerInMinutes = alarm.timeInMinutes - currentTimeInMinutes
-        setupAlarmClock(alarm, triggerInMinutes * 60 - calendar.get(Calendar.SECOND))
-
-        if (showToast) {
-            showRemainingTimeMessage(triggerInMinutes)
-        }
-    } else if (alarm.days == TOMORROW_BIT) {
-        val triggerInMinutes = alarm.timeInMinutes - currentTimeInMinutes + DAY_MINUTES
-        setupAlarmClock(alarm, triggerInMinutes * 60 - calendar.get(Calendar.SECOND))
-
-        if (showToast) {
-            showRemainingTimeMessage(triggerInMinutes)
-        }
-    } else {
-        for (i in 0..7) {
-            val currentDay = (calendar.get(Calendar.DAY_OF_WEEK) + 5) % 7
-            val isCorrectDay = alarm.days and 2.0.pow(currentDay).toInt() != 0
-            if (isCorrectDay && (alarm.timeInMinutes > currentTimeInMinutes || i > 0)) {
-                val triggerInMinutes = alarm.timeInMinutes - currentTimeInMinutes + (i * DAY_MINUTES)
-                setupAlarmClock(alarm, triggerInMinutes * 60 - calendar.get(Calendar.SECOND))
-
-                if (showToast) {
-                    showRemainingTimeMessage(triggerInMinutes)
-                }
-                break
-            } else {
-                calendar.add(Calendar.DAY_OF_MONTH, 1)
-            }
-        }
+    if (showToast) {
+        val now = Calendar.getInstance()
+        val triggerInMillis = triggerTime.timeInMillis - now.timeInMillis
+        showRemainingTimeMessage((triggerInMillis / (1000 * 60)).toInt())
     }
 }
 
@@ -142,9 +115,10 @@ fun Context.showRemainingTimeMessage(totalMinutes: Int) {
     toast(fullString, Toast.LENGTH_LONG)
 }
 
-fun Context.setupAlarmClock(alarm: Alarm, triggerInSeconds: Int) {
+fun Context.setupAlarmClock(alarm: Alarm, triggerTime: Calendar) {
     val alarmManager = getSystemService(Context.ALARM_SERVICE) as AlarmManager
-    val targetMS = System.currentTimeMillis() + triggerInSeconds * 1000
+
+    val targetMS = triggerTime.timeInMillis
     try {
         AlarmManagerCompat.setAlarmClock(alarmManager, targetMS, getOpenAlarmTabIntent(), getAlarmIntent(alarm))
 
@@ -277,35 +251,27 @@ fun Context.getClosestEnabledAlarmString(callback: (result: String) -> Unit) {
             return@getEnabledAlarms
         }
 
+        val now = Calendar.getInstance()
         val nextAlarmList = enabledAlarms
-            .mapNotNull { getTimeUntilNextAlarm(it.timeInMinutes, it.days) }
+            .mapNotNull { getTimeOfNextAlarm(it.timeInMinutes, it.days) }
+            .filter { it > now }
 
-        if (nextAlarmList.isEmpty()) {
-            callback("")
-        }
+        val closestAlarmTime = nextAlarmList.minOrNull()
 
-        var closestAlarmTime = Int.MAX_VALUE
-        nextAlarmList.forEach { time ->
-            if (time < closestAlarmTime) {
-                closestAlarmTime = time
-            }
-        }
-
-        if (closestAlarmTime == Int.MAX_VALUE) {
+        if (closestAlarmTime == null) {
             callback("")
+            return@getEnabledAlarms
         }
 
-        val calendar = Calendar.getInstance().apply { firstDayOfWeek = Calendar.MONDAY }
-        calendar.add(Calendar.MINUTE, closestAlarmTime)
-        val dayOfWeekIndex = (calendar.get(Calendar.DAY_OF_WEEK) + 5) % 7
+        val dayOfWeekIndex = (closestAlarmTime.get(Calendar.DAY_OF_WEEK) + 5) % 7
         val dayOfWeek = resources.getStringArray(org.fossify.commons.R.array.week_days_short)[dayOfWeekIndex]
         val pattern = if (DateFormat.is24HourFormat(this)) {
             "HH:mm"
         } else {
             "h:mm a"
         }
 
-        val formattedTime = SimpleDateFormat(pattern, Locale.getDefault()).format(calendar.time)
+        val formattedTime = SimpleDateFormat(pattern, Locale.getDefault()).format(closestAlarmTime.time)
         callback("$dayOfWeek $formattedTime")
     }
 }

app/src/main/kotlin/org/fossify/clock/helpers/Constants.kt

@@ -111,14 +111,14 @@ fun formatTime(showSeconds: Boolean, use24HourFormat: Boolean, hours: Int, minut
 fun getTomorrowBit(): Int {
     val calendar = Calendar.getInstance()
     calendar.add(Calendar.DAY_OF_WEEK, 1)
-    val dayOfWeek = (calendar.get(Calendar.DAY_OF_WEEK) + 5) % 7
-    return 2.0.pow(dayOfWeek).toInt()
+    val day = calendar.get(Calendar.DAY_OF_WEEK)
+    return getBitForCalendarDay(day)
 }
 
 fun getTodayBit(): Int {
     val calendar = Calendar.getInstance()
-    val dayOfWeek = (calendar.get(Calendar.DAY_OF_WEEK) + 5) % 7
-    return 2.0.pow(dayOfWeek).toInt()
+    val day = calendar.get(Calendar.DAY_OF_WEEK)
+    return getBitForCalendarDay(day)
 }
 
 fun getBitForCalendarDay(day: Int): Int {
@@ -222,39 +222,37 @@ fun getAllTimeZones() = arrayListOf(
     MyTimeZone(89, "GMT+13:00 Tongatapu", "Pacific/Tongatapu")
 )
 
-fun getTimeUntilNextAlarm(alarmTimeInMinutes: Int, days: Int): Int? {
-    val calendar = Calendar.getInstance()
-    calendar.firstDayOfWeek = Calendar.MONDAY
-    val currentTimeInMinutes = calendar.get(Calendar.HOUR_OF_DAY) * 60 + calendar.get(Calendar.MINUTE)
-    val currentDayOfWeek = calendar.get(Calendar.DAY_OF_WEEK) - Calendar.MONDAY
+fun getTimeOfNextAlarm(alarmTimeInMinutes: Int, days: Int): Calendar? {
+    val nextAlarmTime = Calendar.getInstance()
+    nextAlarmTime.firstDayOfWeek = Calendar.MONDAY
+
+    val hour = alarmTimeInMinutes / 60
+    val minute = alarmTimeInMinutes % 60
 
-    var minTimeDifferenceInMinutes = Int.MAX_VALUE
+    nextAlarmTime.set(Calendar.HOUR_OF_DAY, hour)
+    nextAlarmTime.set(Calendar.MINUTE, minute)
+    nextAlarmTime.set(Calendar.SECOND, 0)
+    nextAlarmTime.set(Calendar.MILLISECOND, 0)
 
-    for (i in 0..6) {
-        val alarmDayOfWeek = (currentDayOfWeek + i) % 7
-        if (isAlarmEnabledForDay(alarmDayOfWeek, days)) {
-            val timeDifferenceInMinutes = getTimeDifferenceInMinutes(currentTimeInMinutes, alarmTimeInMinutes, i)
-            if (timeDifferenceInMinutes < minTimeDifferenceInMinutes) {
-                minTimeDifferenceInMinutes = timeDifferenceInMinutes
+    return when (days) {
+        TODAY_BIT -> {
+            // do nothing, alarm is today
+            nextAlarmTime
+        }
+        TOMORROW_BIT -> {
+            nextAlarmTime.apply { add(Calendar.DAY_OF_MONTH, 1) }
+        }
+        else -> {
+            val now = Calendar.getInstance()
+            repeat(8) {
+                val currentDay = (nextAlarmTime.get(Calendar.DAY_OF_WEEK) + 5) % 7
+                if (days.isBitSet(currentDay) && now < nextAlarmTime) {
+                    return nextAlarmTime
+                } else {
+                    nextAlarmTime.add(Calendar.DAY_OF_MONTH, 1)
+                }
             }
+            null
         }
     }
-
-    return if (minTimeDifferenceInMinutes != Int.MAX_VALUE) {
-        minTimeDifferenceInMinutes
-    } else {
-        null
-    }
-}
-
-fun isAlarmEnabledForDay(day: Int, alarmDays: Int) = alarmDays.isBitSet(day)
-
-fun getTimeDifferenceInMinutes(currentTimeInMinutes: Int, alarmTimeInMinutes: Int, daysUntilAlarm: Int): Int {
-    val minutesInADay = 24 * 60
-    val minutesUntilAlarm = daysUntilAlarm * minutesInADay + alarmTimeInMinutes
-    return if (minutesUntilAlarm > currentTimeInMinutes) {
-        minutesUntilAlarm - currentTimeInMinutes
-    } else {
-        minutesInADay - (currentTimeInMinutes - minutesUntilAlarm)
-    }
 }

app/src/main/kotlin/org/fossify/clock/services/SnoozeService.kt

@@ -8,12 +8,13 @@ import org.fossify.clock.extensions.hideNotification
 import org.fossify.clock.extensions.setupAlarmClock
 import org.fossify.clock.helpers.ALARM_ID
 import org.fossify.commons.helpers.MINUTE_SECONDS
+import java.util.Calendar
 
 class SnoozeService : IntentService("Snooze") {
     override fun onHandleIntent(intent: Intent?) {
         val id = intent!!.getIntExtra(ALARM_ID, -1)
         val alarm = dbHelper.getAlarmWithId(id) ?: return
         hideNotification(id)
-        setupAlarmClock(alarm, config.snoozeTime * MINUTE_SECONDS)
+        setupAlarmClock(alarm, Calendar.getInstance().apply { add(Calendar.MINUTE, config.snoozeTime) })
     }
 }