Adds more unfinished code for parsing and tab-completing advanced cost

src/main/java/net/knarcraft/blacksmith/property/CostType.java

@@ -0,0 +1,49 @@
+package net.knarcraft.blacksmith.property;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * The type of costs applicable to an advanced cost configuration
+ */
+public enum CostType {
+
+    /**
+     * A monetary cost from an economy plugin
+     */
+    ECONOMY,
+
+    /**
+     * A permission requirement, rather than a cost
+     */
+    PERMISSION,
+
+    /**
+     * In-game experience levels
+     */
+    EXP,
+
+    /**
+     * A specific item is consumed
+     */
+    ITEM,
+    ;
+
+    /**
+     * Parses a text string denoting a cost type
+     *
+     * @param input <p>The input to parse</p>
+     * @return <p>The parsed cost type, or null if not matched</p>
+     */
+    @Nullable
+    public static CostType parse(@NotNull String input) {
+        String normalized = input.trim().toUpperCase();
+        for (CostType costType : CostType.values()) {
+            if (normalized.equals(costType.name())) {
+                return costType;
+            }
+        }
+        return null;
+    }
+
+}