Only insert initial record if db is empty

And not everytime the history value is 0.

Author: markusfisch

app/src/main/kotlin/de/markusfisch/android/screentime/activity/MainActivity.kt

@@ -125,14 +125,7 @@ class MainActivity : Activity() {
 		val d = days + 1
 		val daysString = resources.getQuantityString(R.plurals.days, d, d)
 		scope.launch {
-			val now = System.currentTimeMillis()
-			val availableHistoryInDays = db.getAvailableHistoryInDays(now)
-			if (availableHistoryInDays < 1) {
-				// Insert an initial SCREEN_ON event if the database is
-				// empty because we can only find an empty database if
-				// the user has started this app for the first time.
-				db.insertScreenEvent(now, true, 0f)
-			}
+			val availableHistoryInDays = db.getAvailableHistoryInDays()
 			val bitmap = chart.draw(
 				timestamp,
 				days,

app/src/main/kotlin/de/markusfisch/android/screentime/data/Database.kt

@@ -16,11 +16,19 @@ class Database {
 		db = OpenHelper(context).writableDatabase
 	}
 
-	fun getAvailableHistoryInDays(now: Long): Int {
+	fun getAvailableHistoryInDays(
+		now: Long = System.currentTimeMillis()
+	): Int {
 		val earliestTimestamp = db.getEarliestTimestamp()
 		if (earliestTimestamp > -1) {
 			val msBetween = startOfDay(now) - startOfDay(earliestTimestamp)
 			return ceil(msBetween / 86400000.0).toInt()
+		} else {
+			// Insert an initial SCREEN_ON event if the database is
+			// empty because we can only find an empty database if
+			// the user has started this app for the first time,
+			// in which case the screen must be on.
+			insertScreenEvent(now, true, 0f)
 		}
 		return 0
 	}