From 93377b6027b56a50038e2d67e19b7f54b1d2caea Mon Sep 17 00:00:00 2001
From: Indyuce <cym.peyrat@yahoo.fr>
Date: Mon, 25 Apr 2022 21:09:01 +0200
Subject: [PATCH] Fixed chest tier chance rolling

---
 .../Indyuce/mmocore/loot/chest/ChestTier.java |  7 +++++--
 .../mmocore/loot/chest/LootChestRegion.java   | 19 ++++++++++++-------
 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/src/main/java/net/Indyuce/mmocore/loot/chest/ChestTier.java b/src/main/java/net/Indyuce/mmocore/loot/chest/ChestTier.java
index 770c7986..de9ea2a3 100644
--- a/src/main/java/net/Indyuce/mmocore/loot/chest/ChestTier.java
+++ b/src/main/java/net/Indyuce/mmocore/loot/chest/ChestTier.java
@@ -10,8 +10,7 @@ public class ChestTier {
 	private final TierEffect effect;
 	private final ScalingFormula capacity;
 	private final DropTable table;
-
-	public final double chance;
+	private final double chance;
 
 	public ChestTier(ConfigurationSection config) {
 		effect = config.isConfigurationSection("effect") ? new TierEffect(config.getConfigurationSection("effect")) : null;
@@ -24,6 +23,10 @@ public class ChestTier {
 		return capacity.calculate(player.getLevel());
 	}
 
+	public double getChance() {
+		return chance;
+	}
+
 	public DropTable getDropTable() {
 		return table;
 	}
diff --git a/src/main/java/net/Indyuce/mmocore/loot/chest/LootChestRegion.java b/src/main/java/net/Indyuce/mmocore/loot/chest/LootChestRegion.java
index ef7e8217..c234d155 100644
--- a/src/main/java/net/Indyuce/mmocore/loot/chest/LootChestRegion.java
+++ b/src/main/java/net/Indyuce/mmocore/loot/chest/LootChestRegion.java
@@ -119,14 +119,19 @@ public class LootChestRegion {
     // TODO stat to increase chance to get higher tiers?
     public ChestTier rollTier() {
 
-        double s = 0;
-        for (ChestTier tier : tiers) {
-            if (random.nextDouble() < tier.chance / (1 - s))
-                return tier;
-            s += tier.chance;
-        }
+        // Calculate sum of all chances and then normalize
+        double norm = 0;
+        for (ChestTier tier : tiers)
+            norm += tier.getChance();
 
-        return tiers.stream().findAny().orElse(null);
+        Validate.isTrue(norm > 0, "No tier was found");
+
+        double sum = 0;
+        for (ChestTier tier : tiers)
+            if (random.nextDouble() < (sum += tier.getChance()) / norm)
+                return tier;
+
+        throw new RuntimeException("Could not roll random chest tier");
     }
 
     public Location getRandomLocation(Location center) {