Fix/updater scheduling auto updates (#615)

* Trigger missed auto global update immediately on server start

In case the last execution was missed, it was never immediately scheduled.
Thus, it had to be waited for the next scheduled execution to be executed.

* Schedule auto global updates at a later point during the startup

In case a global update was triggered immediately, the server setup wasn't far enough causing an error due to trying to use things (e.g. database) that weren't initialized yet

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/update/Updater.kt

@@ -52,10 +52,6 @@ class Updater : IUpdater {
 
     private var currentUpdateTaskId = ""
 
-    init {
-        scheduleUpdateTask()
-    }
-
     private fun autoUpdateTask() {
         val lastAutomatedUpdate = preferences.getLong(lastAutomatedUpdateKey, 0)
         preferences.putLong(lastAutomatedUpdateKey, System.currentTimeMillis())
@@ -69,7 +65,7 @@ class Updater : IUpdater {
         addCategoriesToUpdateQueue(Category.getCategoryList(), true)
     }
 
-    private fun scheduleUpdateTask() {
+    fun scheduleUpdateTask() {
         HAScheduler.deschedule(currentUpdateTaskId)
 
         val isAutoUpdateDisabled = serverConfig.globalUpdateInterval == 0.0
@@ -79,9 +75,14 @@ class Updater : IUpdater {
 
         val updateInterval = serverConfig.globalUpdateInterval.hours.coerceAtLeast(6.hours).inWholeMilliseconds
         val lastAutomatedUpdate = preferences.getLong(lastAutomatedUpdateKey, 0)
-        val initialDelay = updateInterval - (System.currentTimeMillis() - lastAutomatedUpdate) % updateInterval
+        val timeToNextExecution = updateInterval - (System.currentTimeMillis() - lastAutomatedUpdate) % updateInterval
 
-        HAScheduler.schedule(::autoUpdateTask, updateInterval, initialDelay, "global-update")
+        val wasPreviousUpdateTriggered = System.currentTimeMillis() - (if (lastAutomatedUpdate > 0) lastAutomatedUpdate else System.currentTimeMillis()) < updateInterval
+        if (!wasPreviousUpdateTriggered) {
+            autoUpdateTask()
+        }
+
+        HAScheduler.schedule(::autoUpdateTask, updateInterval, timeToNextExecution, "global-update")
     }
 
     private fun getOrCreateUpdateChannelFor(source: String): Channel<UpdateJob> {

server/src/main/kotlin/suwayomi/tachidesk/server/ServerSetup.kt

@@ -184,6 +184,9 @@ fun applicationSetup() {
     // AES/CBC/PKCS7Padding Cypher provider for zh.copymanga
     Security.addProvider(BouncyCastleProvider())
 
+    // start automated global updates
+    updater.scheduleUpdateTask()
+
     // start automated backups
     ProtoBackupExport.scheduleAutomatedBackupTask()