Added head arg parser

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/items/ArgParserHead.kt

@@ -0,0 +1,53 @@
+package com.willfp.eco.internal.items
+
+import com.willfp.eco.core.items.args.LookupArgParser
+import org.bukkit.Bukkit
+import org.bukkit.inventory.ItemStack
+import org.bukkit.inventory.meta.ItemMeta
+import org.bukkit.inventory.meta.SkullMeta
+import java.util.function.Predicate
+
+object ArgParserHead : LookupArgParser {
+    override fun parseArguments(args: Array<out String>, meta: ItemMeta): Predicate<ItemStack>? {
+        if (meta !is SkullMeta) {
+            return null
+        }
+
+        var playerName: String? = null
+
+        for (arg in args) {
+            val argSplit = arg.split(":")
+            if (!argSplit[0].equals("head", ignoreCase = true)) {
+                continue
+            }
+            if (argSplit.size < 2) {
+                continue
+            }
+            playerName = argSplit[1]
+        }
+
+        playerName ?: return null
+
+        @Suppress("DEPRECATION")
+        val player = Bukkit.getOfflinePlayer(playerName)
+
+        meta.owningPlayer = player
+
+        return Predicate {
+            val testMeta = it.itemMeta as? SkullMeta ?: return@Predicate false
+            testMeta.owningPlayer?.uniqueId == player.uniqueId
+        }
+    }
+
+    override fun serializeBack(meta: ItemMeta): String? {
+        if (meta !is SkullMeta) {
+            return null
+        }
+
+        if (meta.owningPlayer == null) {
+            return null
+        }
+
+        return "head:${meta.owningPlayer?.name}"
+    }
+}

eco-core/core-plugin/src/main/kotlin/com/willfp/eco/internal/spigot/EcoSpigotPlugin.kt

@@ -45,6 +45,7 @@ import com.willfp.eco.internal.items.ArgParserColor
 import com.willfp.eco.internal.items.ArgParserCustomModelData
 import com.willfp.eco.internal.items.ArgParserEnchantment
 import com.willfp.eco.internal.items.ArgParserFlag
+import com.willfp.eco.internal.items.ArgParserHead
 import com.willfp.eco.internal.items.ArgParserName
 import com.willfp.eco.internal.items.ArgParserTexture
 import com.willfp.eco.internal.items.ArgParserUnbreakable
@@ -150,6 +151,7 @@ abstract class EcoSpigotPlugin : EcoPlugin() {
         Items.registerArgParser(ArgParserFlag)
         Items.registerArgParser(ArgParserUnbreakable)
         Items.registerArgParser(ArgParserName)
+        Items.registerArgParser(ArgParserHead)
 
         Entities.registerArgParser(EntityArgParserName)
         Entities.registerArgParser(EntityArgParserNoAI)