Split some common code from event handlers into new class OperationUtils.

src/main/java/dev/micle/xptools/operation/OperationUtils.java

@@ -0,0 +1,76 @@
+package dev.micle.xptools.operation;
+
+import net.minecraft.tags.TagKey;
+
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.List;
+import java.util.concurrent.ThreadLocalRandom;
+
+public class OperationUtils {
+    public static <T extends TagKey<?>> List<OperationItem> calculateOperationList(String id, List<T> tagList, List<OperationItem> operationItems) {
+        List<OperationItem> operations = new ArrayList<>();
+
+        // Collect operations on relevant id
+        if (!id.isEmpty()) {
+            for (OperationItem operationItem : operationItems) {
+                if (!operationItem.isTag() && operationItem.getId().equals(id)) {
+                    operations.add(operationItem);
+                }
+            }
+        }
+
+        // Collect operations on relevant tag_id
+        for (T tagKey : tagList) {
+            String tag_id = tagKey.location().toString();
+            for (OperationItem operationItem : operationItems) {
+                if (operationItem.isTag() && operationItem.getId().equals(tag_id)) {
+                    operations.add(operationItem);
+                }
+            }
+        }
+
+        // Sort operations based on priority
+        operations.sort(Comparator.comparingInt(OperationItem::getPriority));
+
+        // Remove any operations after last operation
+        for (OperationItem operationItem : operations) {
+            if (operationItem.isLast()) {
+                operations = operations.subList(0, operations.indexOf(operationItem) + 1);
+                break;
+            }
+        }
+
+        return operations;
+    }
+
+    public static float calculateNewXpAmount(float xp, List<OperationItem> operations) {
+        for (OperationItem operation : operations) {
+            // Calculate operation value
+            float opValue = (operation.getMin() == operation.getMax()) ?
+                    operation.getMin() :
+                    ThreadLocalRandom.current().nextFloat(operation.getMin(), operation.getMax());
+
+            // Apply operation
+            switch (operation.getType()) {
+                case SET:
+                    xp = opValue;
+                    break;
+                case ADD:
+                    xp += opValue;
+                    break;
+                case SUBTRACT:
+                    xp -= opValue;
+                    break;
+                case MULTIPLY:
+                    xp *= opValue;
+                    break;
+                case DIVIDE:
+                    xp /= opValue;
+                    break;
+            }
+        }
+
+        return xp;
+    }
+}