Initial commit

src/main/kotlin/io/delilaheve/util/ItemUtil.kt

@@ -0,0 +1,83 @@
+package io.delilaheve.util
+
+import io.delilaheve.UnsafeEnchants
+import org.bukkit.Material.BOOK
+import org.bukkit.Material.ENCHANTED_BOOK
+import org.bukkit.enchantments.Enchantment
+import org.bukkit.inventory.ItemStack
+import org.bukkit.inventory.meta.EnchantmentStorageMeta
+
+/**
+ * Item manipulation utilities
+ */
+object ItemUtil {
+
+    /**
+     * Check if this [ItemStack] is a [BOOK] or [ENCHANTED_BOOK]
+     */
+    fun ItemStack.isBook() = type in listOf(BOOK, ENCHANTED_BOOK)
+
+    /**
+     * Check if this [ItemStack] is an [ENCHANTED_BOOK]
+     */
+    private fun ItemStack.isEnchantedBook() = type == ENCHANTED_BOOK
+
+    /**
+     * Determine if this [ItemStack] can hold enchants, this should be sufficient for
+     * detecting if an item is a tool/armour/etc... and not a carrot/potato/etc...
+     */
+    private fun ItemStack.canHoldEnchants() = Enchantment.values()
+        .any { it.canEnchantItem(this) }
+
+    /**
+     * Find the enchantment map for this [ItemStack] and return it as a [MutableMap]
+     */
+    fun ItemStack.findEnchantments() = if (isBook()) {
+        (itemMeta as? EnchantmentStorageMeta)?.storedEnchants ?: emptyMap()
+    } else {
+        itemMeta?.enchants ?: emptyMap()
+    }
+
+    /**
+     * Apply an [enchantments] map to this [ItemStack]
+     */
+    fun ItemStack.setEnchantmentsUnsafe(enchantments: Map<Enchantment, Int>) {
+        if (isBook()) {
+            /* For some god-forsaken reason, item meta is not mutable
+             * so, we have to get the instance, modify it, then set it
+             * back to the item... #BecauseMinecraft */
+            val bookMeta = (itemMeta as? EnchantmentStorageMeta)
+            bookMeta?.replaceEnchants(enchantments)
+            itemMeta = bookMeta
+        } else {
+            itemMeta?.enchants?.forEach { (enchant, _) ->
+                removeEnchantment(enchant)
+            }
+            addUnsafeEnchantments(enchantments)
+        }
+    }
+
+    /**
+     * Apply an [enchantments] map to this book
+     */
+    private fun EnchantmentStorageMeta.replaceEnchants(
+        enchantments: Map<Enchantment, Int>
+    ) {
+        storedEnchants.forEach { (enchant, _) ->
+            removeStoredEnchant(enchant)
+        }
+        enchantments.forEach { (enchant, level) ->
+            val added = addStoredEnchant(enchant, level, true)
+            UnsafeEnchants.log("${enchant.key} added to item? $added")
+        }
+    }
+
+    /**
+     * Check that this [ItemStack] can merge with the [other]
+     *
+     * The two items should either be the same type, or, the [other] is a book
+     */
+    fun ItemStack.canMergeWith(
+        other: ItemStack
+    ) = type == other.type || (canHoldEnchants() && other.isEnchantedBook())
+}