Started work on material payments

src/main/java/me/tychsen/enchantgui/config/EShopConfig.java

@@ -4,11 +4,8 @@
 import com.github.sarhatabaot.kraken.core.config.ConfigFile;
 import lombok.Setter;
 import me.tychsen.enchantgui.EnchantGUIPlugin;
-import me.tychsen.enchantgui.economy.NullPayment;
-import me.tychsen.enchantgui.economy.PaymentStrategy;
-import me.tychsen.enchantgui.economy.PlayerPointsPayment;
-import me.tychsen.enchantgui.economy.VaultPayment;
-import me.tychsen.enchantgui.economy.XPPayment;
+import me.tychsen.enchantgui.economy.*;
+import org.bukkit.Material;
 import org.bukkit.command.CommandSender;
 import org.bukkit.enchantments.Enchantment;
 import org.jetbrains.annotations.NotNull;
@@ -94,12 +91,31 @@ public PaymentStrategy getPaymentStrategy() {
                 case "money" -> setEconomy(new VaultPayment());
                 case "xp" -> setEconomy(new XPPayment());
                 case "playerpoints" -> setEconomy(new PlayerPointsPayment());
-                default -> setEconomy(new NullPayment());
+                default -> {
+                    final Material possibleMaterial = checkMaterialCurrency();
+                    if(possibleMaterial == Material.AIR) {
+                        setEconomy(new NullPayment());
+                    } else {
+                        setEconomy(new MaterialPayment(possibleMaterial));
+                    }
+
+                }
             }
         }
         return economy;
     }
 
+    private Material checkMaterialCurrency() {
+        final String paymentType = getPaymentType();
+        if(paymentType.startsWith("material")) {
+            final String possibleMaterial = paymentType.split(":")[1];
+            return Material.matchMaterial(possibleMaterial.toUpperCase());
+        }
+
+        EnchantGUIPlugin.getInstance().getLogger().warning(() -> "Could not find matching material.");
+        return Material.AIR;
+    }
+
     public String getLanguage() {
         return config.getString("language", "en");
     }

src/main/java/me/tychsen/enchantgui/economy/MaterialPayment.java

@@ -0,0 +1,55 @@
+package me.tychsen.enchantgui.economy;
+
+import org.bukkit.Material;
+import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Arrays;
+
+public class MaterialPayment implements PaymentStrategy {
+    private final Material material;
+
+    public MaterialPayment(Material material) {
+        this.material = material;
+    }
+
+    @Override
+    public boolean withdraw(@NotNull Player player, int amount) {
+        if(!hasSufficientFunds(player,amount)) return false;
+
+        //do stuff
+        return true;
+    }
+
+    @Override
+    public boolean withdraw(@NotNull Player player, double amount) {
+        return withdraw(player, (int) amount);
+    }
+
+    //todo not precise.
+    @Override
+    public boolean hasSufficientFunds(@NotNull Player player, int amount) {
+        final int count = Arrays.stream(player.getInventory().getContents())
+                .filter(itemStack -> itemStack.getType() == material)
+                .mapToInt(ItemStack::getAmount)
+                .sum();
+
+        return count >= amount;
+    }
+
+    @Override
+    public boolean hasSufficientFunds(@NotNull Player player, double amount) {
+        return hasSufficientFunds(player, (int) amount);
+    }
+
+    @Override
+    public String name() {
+        return "MaterialPayment";
+    }
+
+    @Override
+    public String getCurrency() {
+        return material.name().toLowerCase();
+    }
+}

src/main/resources/config.yml

@@ -7,8 +7,11 @@ opt-out: false
 # Max 32 characters!
 menu-name: "EnchantGUI"
 
-# Payment currency can be one of two. Either 'money' for regular money (using Vault+Economy system)
-# or 'xp' for XP levels.
+# Payment currency options:
+# 1. Either 'money' for regular money (using Vault+Economy system)
+# 2. 'xp' for XP levels.
+# 3. 'pp' for player points.
+# 4. 'material:id' for a specific material, for example, emeralds.
 # You can also put 'disable' to disable the economy-aspect of the plugin entirely.
 payment-currency: money