Version 1.5.0-pre3:

* Added global setting for per-player cooldowns

To-do:
* Add per-villager restock cooldowns
* Add enchantments, data, etc. to ingredients and result
* Add config editor GUI in-game

src/com/pretzel/dev/villagertradelimiter/data/Cooldown.java

@@ -2,13 +2,20 @@ package com.pretzel.dev.villagertradelimiter.data;
 
 import com.pretzel.dev.villagertradelimiter.lib.Util;
 
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.Locale;
+
 public class Cooldown {
+    private static final SimpleDateFormat FORMAT = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.ENGLISH);
+
     private enum Interval {
-        s(1000L),
+        s(1L),
-        m(60000L),
+        m(60L),
-        h(3600000L),
+        h(3600L),
-        d(86400000L),
+        d(86400L),
-        w(604800000L);
+        w(604800L);
 
         final long factor;
         Interval(long factor) {
@@ -17,17 +24,31 @@ public class Cooldown {
     }
 
     /**
-     * @param timeStr The cooldown time as written in config.yml (7d, 30s, 5m, etc)
+     * @param cooldownStr The cooldown time as written in config.yml (7d, 30s, 5m, etc)
-     * @return The cooldown time in milliseconds
+     * @return The cooldown time in seconds
      */
-    public static long parseTime(final String timeStr) {
+    public static long parseCooldown(final String cooldownStr) {
+        if(cooldownStr.equals("0")) return 0;
         try {
-            long time = Long.parseLong(timeStr.substring(0, timeStr.length()-1));
+            long time = Long.parseLong(cooldownStr.substring(0, cooldownStr.length()-1));
-            String interval = timeStr.substring(timeStr.length()-1).toLowerCase();
+            String interval = cooldownStr.substring(cooldownStr.length()-1).toLowerCase();
             return time * Interval.valueOf(interval).factor;
         } catch (Exception e) {
             Util.errorMsg(e);
         }
         return 0;
     }
+
+    public static String formatTime(Date date) {
+        return FORMAT.format(date);
+    }
+
+    public static Date parseTime(final String timeStr) {
+        try {
+            return FORMAT.parse(timeStr);
+        } catch (ParseException e) {
+            Util.errorMsg(e);
+        }
+        return null;
+    }
 }

src/com/pretzel/dev/villagertradelimiter/data/PlayerData.java

@@ -5,7 +5,7 @@ import com.pretzel.dev.villagertradelimiter.wrappers.VillagerWrapper;
 import java.util.HashMap;
 
 public class PlayerData {
-    private final HashMap<String, Long> tradingCooldowns;
+    private final HashMap<String, String> tradingCooldowns;
     private VillagerWrapper tradingVillager;
 
     public PlayerData() {
@@ -14,7 +14,7 @@ public class PlayerData {
     }
 
     /** @return The map of items to timestamps for the player's trading history */
-    public HashMap<String, Long> getTradingCooldowns() { return this.tradingCooldowns; }
+    public HashMap<String, String> getTradingCooldowns() { return this.tradingCooldowns; }
 
     /** @param tradingVillager The villager that this player is currently trading with */
     public void setTradingVillager(final VillagerWrapper tradingVillager) { this.tradingVillager = tradingVillager; }

src/com/pretzel/dev/villagertradelimiter/database/DatabaseManager.java

@@ -6,6 +6,8 @@ import com.pretzel.dev.villagertradelimiter.data.PlayerData;
 import com.pretzel.dev.villagertradelimiter.lib.Util;
 import org.bukkit.configuration.ConfigurationSection;
 
+import java.time.Instant;
+import java.util.Date;
 import java.util.UUID;
 
 public class DatabaseManager {
@@ -13,7 +15,7 @@ public class DatabaseManager {
             "CREATE TABLE IF NOT EXISTS vtl_cooldown("+
                     "uuid CHAR(36) NOT NULL,"+
                     "item VARCHAR(255) NOT NULL,"+
-                    "time BIGINT NOT NULL,"+
+                    "time TEXT NOT NULL,"+
                     "PRIMARY KEY(uuid, item));";
     private static final String SELECT_ITEMS = "SELECT * FROM vtl_cooldown;";
     private static final String INSERT_ITEM = "INSERT OR IGNORE INTO vtl_cooldown(uuid,item,time) VALUES?;"; //INSERT IGNORE INTO for MySQL
@@ -46,7 +48,9 @@ public class DatabaseManager {
 
                     UUID uuid = UUID.fromString(tokens[0]);
                     String item = tokens[1];
-                    long time = Long.parseLong(tokens[2]);
+                    final Date date = Cooldown.parseTime(tokens[2]);
+                    if(date == null) continue;
+                    long time = date.getTime();
 
                     PlayerData playerData = instance.getPlayerData().get(uuid);
                     if(playerData == null) {
@@ -54,9 +58,12 @@ public class DatabaseManager {
                         instance.getPlayerData().put(uuid, playerData);
                     }
 
-                    String cooldown = instance.getCfg().getString("Overrides."+item+".Cooldown", null);
+                    final Date now = Date.from(Instant.now());
-                    if(cooldown != null && System.currentTimeMillis() < time + Cooldown.parseTime(cooldown)) {
+                    final String global = instance.getCfg().getString("Cooldown", "0");
-                        playerData.getTradingCooldowns().put(item, time);
+                    final String local = instance.getCfg().getString("Overrides."+item+".Cooldown", global);
+                    long cooldown = Cooldown.parseCooldown(local);
+                    if(cooldown != 0 && now.getTime()/1000L < time/1000L + cooldown) {
+                        playerData.getTradingCooldowns().put(item, Cooldown.formatTime(date));
                     }
                 }
             }
@@ -81,7 +88,7 @@ public class DatabaseManager {
 
         String values = "";
         for(String item : playerData.getTradingCooldowns().keySet()) {
-            long time = playerData.getTradingCooldowns().get(item);
+            String time = playerData.getTradingCooldowns().get(item);
 
             if(!values.isEmpty()) values += ",";
             values += "('"+uuid+"','"+item+"','"+time+"')";

src/com/pretzel/dev/villagertradelimiter/listeners/InventoryListener.java

@@ -1,6 +1,7 @@
 package com.pretzel.dev.villagertradelimiter.listeners;
 
 import com.pretzel.dev.villagertradelimiter.VillagerTradeLimiter;
+import com.pretzel.dev.villagertradelimiter.data.Cooldown;
 import com.pretzel.dev.villagertradelimiter.data.PlayerData;
 import com.pretzel.dev.villagertradelimiter.lib.Util;
 import com.pretzel.dev.villagertradelimiter.settings.Settings;
@@ -18,7 +19,11 @@ import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.MerchantRecipe;
 
+import java.time.Instant;
+import java.util.Date;
+
 public class InventoryListener implements Listener {
+
     private final VillagerTradeLimiter instance;
     private final Settings settings;
 
@@ -74,7 +79,13 @@ public class InventoryListener implements Listener {
         if(overrides == null) return;
 
         final String type = settings.getType(result, ingredient1, ingredient2);
-        if(type == null || !overrides.contains(type+".Cooldown")) return;
+        if(instance.getCfg().getString("Cooldown", "0").equals("0")) {
+            Util.consoleMsg("global cooldown is 0");
+            if(overrides.getString(type+".Cooldown", "0").equals("0")) {
+                Util.consoleMsg("local cooldown is 0");
+                return;
+            }
+        }
 
         //Get the selected recipe by the items in the slots
         final MerchantRecipe selectedRecipe = getSelectedRecipe((Villager)event.getInventory().getHolder(), ingredient1, ingredient2, result);
@@ -89,7 +100,7 @@ public class InventoryListener implements Listener {
         Bukkit.getScheduler().runTaskLater(instance, () -> {
             int uses = selectedRecipe.getUses();
             if(!playerData.getTradingCooldowns().containsKey(type) && uses >= selectedRecipe.getMaxUses()) {
-                playerData.getTradingCooldowns().put(type, System.currentTimeMillis());
+                playerData.getTradingCooldowns().put(type, Cooldown.formatTime(Date.from(Instant.now())));
             }
         }, 1);
     }

src/com/pretzel/dev/villagertradelimiter/listeners/PlayerListener.java

@@ -16,6 +16,8 @@ import org.bukkit.event.player.PlayerInteractEntityEvent;
 import org.bukkit.potion.PotionEffect;
 import org.bukkit.potion.PotionEffectType;
 
+import java.time.Instant;
+import java.util.Date;
 import java.util.List;
 
 public class PlayerListener implements Listener {
@@ -172,9 +174,14 @@ public class PlayerListener implements Listener {
             final ConfigurationSection overrides = instance.getCfg().getConfigurationSection("Overrides");
             if(overrides != null) {
                 final String type = settings.getType(recipe.getItemStack("sell"), recipe.getItemStack("buy"), recipe.getItemStack("buyB"));
-                if(type != null && overrides.contains(type+".Cooldown")) {
+                final String global = instance.getCfg().getString("Cooldown", "0");
+                final String local = overrides.getString(type+".Cooldown", global);
+                if(type != null && !local.equals("0")) {
                     if(playerData.getTradingCooldowns().containsKey(type)) {
-                        if(System.currentTimeMillis() >= playerData.getTradingCooldowns().get(type) + Cooldown.parseTime(overrides.getString(type+".Cooldown"))) {
+                        final Date now = Date.from(Instant.now());
+                        final Date lastTrade = Cooldown.parseTime(playerData.getTradingCooldowns().get(type));
+                        long cooldown = Cooldown.parseCooldown(local);
+                        if(lastTrade != null && (now.getTime()/1000L >= lastTrade.getTime()/1000L + cooldown)) {
                             playerData.getTradingCooldowns().remove(type);
                         } else {
                             maxUses = 0;

src/com/pretzel/dev/villagertradelimiter/settings/Settings.java

@@ -66,24 +66,34 @@ public class Settings {
         final String resultType = result.getType().name().toLowerCase();
         final String ingredient1Type = ingredient1.getType().name().toLowerCase();
         final String ingredient2Type = ingredient2.getType().name().toLowerCase();
+        final String defaultType;
+        if(result.getType() == Material.EMERALD) {
+            if(ingredient1.getType() == Material.BOOK || ingredient1.getType() == Material.AIR) {
+                defaultType = ingredient2Type;
+            } else {
+                defaultType = ingredient1Type;
+            }
+        } else {
+            defaultType = resultType;
+        }
 
         if(result.getType() == Material.ENCHANTED_BOOK) {
             final EnchantmentStorageMeta meta = (EnchantmentStorageMeta) result.getItemMeta();
-            if(meta == null) return null;
+            if(meta == null) return defaultType;
             for(Enchantment key : meta.getStoredEnchants().keySet()) {
                 if (key != null) {
                     final String itemType = key.getKey().getKey() +"_"+meta.getStoredEnchantLevel(key);
                     if(getItem(ingredient1, result, itemType) != null) return itemType;
                 }
             }
-            return null;
+            return defaultType;
         }
 
         final ItemStack ingredient = (ingredient1.getType() == Material.AIR ? ingredient2 : ingredient1);
         if(getItem(ingredient, result, resultType) != null) return resultType;
         if(getItem(ingredient, result, ingredient1Type) != null) return ingredient1Type;
         if(getItem(ingredient, result, ingredient2Type) != null) return ingredient2Type;
-        return null;
+        return defaultType;
     }
 
     /**

src/main/resources/config.yml

@@ -49,6 +49,18 @@ MaxDemand: -1
 # For more information, see https://minecraft.fandom.com/el/wiki/Trading#Java_Edition
 MaxUses: -1
 
+# The per-player, per-trade cooldown in real-world time.
+# After a player makes a trade <MaxUses> times, the trade will be disabled for the player until the cooldown is over.
+#   * Set to 0 to disable this feature and keep vanilla behavior
+#   * Set to a number and interval to add a per-player, per-trade cooldown for all trades (see below)
+# A valid cooldown follows the <Number><Interval> format, such as 7d or 30s. The valid intervals are:
+#   * s = seconds (e.g. 30s)
+#   * m = minutes (e.g. 10m)
+#   * h = hours   (e.g. 1h)
+#   * d = days    (e.g. 3d)
+#   * w = weeks   (e.g. 2w)
+Cooldown: 0
+
 
 #-------------------------------- PER-ITEM SETTINGS --------------------------------#
 # Override the global settings for individual items. To disable, set like this --> Overrides: none