Add basic folia support

src/main/kotlin/io/delilaheve/CustomAnvil.kt

@@ -115,7 +115,7 @@ class CustomAnvil : JavaPlugin() {
 
         // Load other thing later.
         // It is so other dependent plugins can implement there event listener before we fire them.
-        Bukkit.getScheduler().scheduleSyncDelayedTask(this, {loadEnchantmentSystem()}, 0L)
+        DependencyManager.scheduler.scheduleGlobally(this, {loadEnchantmentSystem()})
     }
 
     private fun loadEnchantmentSystem(){

src/main/kotlin/xyz/alexcrea/cuanvil/dependency/DependencyManager.kt

@@ -7,9 +7,13 @@ import org.bukkit.inventory.AnvilInventory
 import xyz.alexcrea.cuanvil.config.ConfigHolder
 import xyz.alexcrea.cuanvil.dependency.packet.PacketManager
 import xyz.alexcrea.cuanvil.dependency.packet.PacketManagerSelector
+import xyz.alexcrea.cuanvil.dependency.scheduler.BukkitScheduler
+import xyz.alexcrea.cuanvil.dependency.scheduler.PaperScheduler
+import xyz.alexcrea.cuanvil.dependency.scheduler.TaskScheduler
 
 object DependencyManager {
 
+    lateinit var scheduler: TaskScheduler
     lateinit var packetManager: PacketManager
     var enchantmentSquaredCompatibility: EnchantmentSquaredDependency? = null
     var ecoEnchantCompatibility: EcoEnchantDependency? = null
@@ -18,6 +22,11 @@ object DependencyManager {
     fun loadDependency(){
         val pluginManager = Bukkit.getPluginManager()
 
+        // Bukkit or Paper scheduler ?
+        scheduler = if(PaperScheduler.isPaper()) PaperScheduler()
+        else BukkitScheduler()
+
+
         // Packet Manager
         val forceProtocolib = ConfigHolder.DEFAULT_CONFIG.config.getBoolean("force_protocolib", false)
         packetManager = PacketManagerSelector.selectPacketManager(forceProtocolib)

src/main/kotlin/xyz/alexcrea/cuanvil/dependency/scheduler/BukkitScheduler.kt

@@ -0,0 +1,17 @@
+package xyz.alexcrea.cuanvil.dependency.scheduler
+
+import org.bukkit.Bukkit
+import org.bukkit.entity.Entity
+import org.bukkit.plugin.Plugin
+
+class BukkitScheduler : TaskScheduler {
+
+    override fun scheduleGlobally(plugin: Plugin, task: Runnable, time: Long): Any? {
+        return Bukkit.getScheduler().scheduleSyncDelayedTask(plugin, task, time)
+    }
+
+
+    override fun scheduleOnEntity(plugin: Plugin, entity: Entity, task: Runnable, time: Long): Any? {
+        return Bukkit.getScheduler().scheduleSyncDelayedTask(plugin, task, time)
+    }
+}

src/main/kotlin/xyz/alexcrea/cuanvil/listener/ChatEventListener.kt

@@ -1,12 +1,12 @@
 package xyz.alexcrea.cuanvil.listener
 
 import io.delilaheve.CustomAnvil
-import org.bukkit.Bukkit
 import org.bukkit.entity.HumanEntity
 import org.bukkit.event.EventHandler
 import org.bukkit.event.Listener
 import org.bukkit.event.player.AsyncPlayerChatEvent
 import org.bukkit.event.player.PlayerQuitEvent
+import xyz.alexcrea.cuanvil.dependency.DependencyManager
 import java.util.*
 import java.util.concurrent.ConcurrentHashMap
 import java.util.function.Consumer
@@ -39,9 +39,11 @@ class ChatEventListener : Listener {
         event.isCancelled = true
 
         // sync callback with default server thread
-        Bukkit.getScheduler().runTask(CustomAnvil.instance, Runnable {
+        DependencyManager.scheduler.scheduleOnEntity(
+            CustomAnvil.instance, player,
+            Runnable {
             eventCallback.accept(event.message)
-        })
+        }, 0L)
     }
 
 }

src/main/kotlin/xyz/alexcrea/cuanvil/util/AnvilXpUtil.kt

@@ -38,21 +38,20 @@ object AnvilXpUtil {
             anvilCost
         }
 
+        val player = view.player
+
         /* Because Minecraft likes to have the final say in the repair cost displayed
             * we need to wait for the event to end before overriding it, this ensures that
             * we have the final say in the process. */
-        CustomAnvil.instance
-            .server
-            .scheduler
-            .runTask(CustomAnvil.instance, Runnable {
+        DependencyManager.scheduler.scheduleOnEntity(
+            CustomAnvil.instance, player,
+            Runnable {
                 inventory.maximumRepairCost =
                     if (ConfigOptions.doRemoveCostLimit || ignoreRules)
                     { Int.MAX_VALUE }
                     else
                     { ConfigOptions.maxAnvilCost + 1 }
 
-                val player = view.player
-
                 inventory.repairCost = finalAnvilCost
                 view.setProperty(REPAIR_COST, finalAnvilCost)
                 player.openInventory.setProperty(REPAIR_COST, finalAnvilCost)