Event Dependency Feature and important Bug Fix

Events can now have Dependencies.
Events only activate if their Dependencies are active.
Fixed a Bug that caused attempted Activations to never be reset, leading to Events never happening again.

Author: Atilist

src/test/java/net/modificationstation/sltest/celestial/CelestialListener.java

@@ -11,6 +11,7 @@ public class CelestialListener {
 
     public static CelestialEvent flyingDimando;
     public static CelestialEvent fallingDimando;
+    public static CelestialEvent crashingDimando;
     public static CelestialEvent spinningDimando;
     public static CelestialEvent burningDimando;
     public static CelestialEvent longDimando;
@@ -20,13 +21,16 @@ public void registerCelestialEvents(CelestialRegisterEvent event) {
         SLTest.LOGGER.info("Register celestial events for testing");
         flyingDimando = new FlyingDimando(4, "flying_dimando", event.world);
         fallingDimando = new DebugCelestialEvent(2, "falling_dimando", event.world);
+        crashingDimando = new DebugCelestialEvent(2, "crashing_dimando", event.world);
         spinningDimando = new DebugCelestialEvent(4, "spinning_dimando", event.world).setDayOffset(1);
         burningDimando = new DebugCelestialEvent(2, "burning_dimando", event.world).setDayOffset(1);
         longDimando = new DebugCelestialEvent(12, "long_dimando", event.world).setExtraDays(4);
         flyingDimando.addIncompatibleEvent(fallingDimando);
         spinningDimando.addIncompatibleEvent(burningDimando);
+        crashingDimando.addDependency(longDimando);
         CelestialTimeManager.addCelestialEvent(flyingDimando, DayQuarter.MORNING, DayQuarter.MORNING);
         CelestialTimeManager.addCelestialEvent(fallingDimando, DayQuarter.NOON, DayQuarter.MIDNIGHT);
+        CelestialTimeManager.addCelestialEvent(crashingDimando, DayQuarter.NOON, DayQuarter.NOON);
         CelestialTimeManager.addCelestialEvent(spinningDimando, DayQuarter.EVENING, DayQuarter.NOON);
         CelestialTimeManager.addCelestialEvent(burningDimando, DayQuarter.MIDNIGHT, DayQuarter.EVENING);
         CelestialTimeManager.addCelestialEvent(longDimando, DayQuarter.MIDNIGHT, DayQuarter.MIDNIGHT);

station-world-events-v0/src/main/java/net/modificationstation/stationapi/api/celestial/CelestialEvent.java

@@ -26,6 +26,7 @@ public class CelestialEvent {
     private boolean active;
     private boolean initializationNeeded = true;
     private final List<CelestialEvent> incompatibleEvents = new LinkedList<>();
+    private final List<CelestialEvent> dependencies = new LinkedList<>();
     public final World world;
 
     /**
@@ -118,9 +119,22 @@ public boolean activateEvent(long worldTime, Random random) {
                 return false;
             }
         }
-        long days = worldTime / dayLength + dayOffset;
+        for (CelestialEvent otherEvent : dependencies) {
+            if (otherEvent == null) continue;
+            if (!otherEvent.isActive()) {
+                activityState.active = false;
+                activityState.attemptedActivation = true;
+                activityState.markDirty();
+                return false;
+            }
+        }
+        long days = (worldTime / dayLength) + dayOffset;
+        if (days % frequency > extraDays) {
+            activityState.attemptedActivation = false;
+            return false;
+        }
         if (!activityState.attemptedActivation) {
-            active = days % frequency == 0 && random.nextFloat() <= chance;
+            active = days % frequency <= extraDays && random.nextFloat() <= chance;
         }
         if (active) {
             activityState.active = true;
@@ -162,7 +176,7 @@ public void updateEvent(long worldTime) {
         if (!active && !activityState.active) return;
         worldTime -= startingDaytime;
         worldTime += endingDaytime;
-        long days = worldTime / dayLength + dayOffset;
+        long days = (worldTime / dayLength) + dayOffset;
         active = days % frequency <= extraDays;
         activityState.active = active;
         if (!active) {
@@ -234,6 +248,17 @@ public void addIncompatibleEvent(CelestialEvent otherEvent) {
         otherEvent.addIncompatibleEvent(this);
     }
 
+    /**
+     * Adds dependency to an event, meaning another event has to happen for this one to happen.
+     * Dependency only gets added into one direction.
+     *
+     * @param dependency Event to be added to the dependencies list.
+     */
+    public void addDependency(CelestialEvent dependency) {
+        if (dependencies.contains(dependency)) return;
+        dependencies.add(dependency);
+    }
+
     /**
      * Used by CelestialTimeManager to handle an edge-case where events would not be loaded when reloading the same world.
      */