Good spot

mods/ShopMod.properties

@@ -17,3 +17,8 @@ itemJsonPath=mods/shop_items.json
 
 # java.util.logging level for this mod (e.g., INFO, FINE)
 logLevel=INFO
+
+# Dump trader inventories to a shop_items.json-compatible file on startup (set back to false after dumping)
+dumpTraders=true
+dumpTradersCategoryId=1
+dumpTradersOutputPath=mods/shop_items.json

src/main/java/mod/treestar/shopmod/ShopMod.java

@@ -3,6 +3,7 @@ package mod.treestar.shopmod;
 import mod.treestar.shopmod.categoryprovider.JsonShopCategoryProvider;
 import mod.treestar.shopmod.itemprovider.JsonShopItemProvider;
 import mod.treestar.shopmod.ShopOpenAction;
+import mod.treestar.shopmod.util.TraderItemExporter;
 import org.gotti.wurmunlimited.modloader.interfaces.Configurable;
 import org.gotti.wurmunlimited.modloader.interfaces.Initable;
 import org.gotti.wurmunlimited.modloader.interfaces.ServerStartedListener;
@@ -23,6 +24,9 @@ public class ShopMod implements WurmServerMod, Initable, Configurable, ServerSta
     private String itemJsonPath = "mods/shop/items.json";
     private Level logLevel = Level.INFO;
     private ShopService shopService;
+    private boolean dumpTraders = false;
+    private int dumpTradersCategoryId = 1;
+    private String dumpTradersOutputPath = "mods/shop/items.json";
 
     @Override
     public void configure(Properties properties) {
@@ -32,6 +36,9 @@ public class ShopMod implements WurmServerMod, Initable, Configurable, ServerSta
         categoryJsonPath = properties.getProperty("categoryJsonPath", categoryJsonPath);
         itemJsonPath = properties.getProperty("itemJsonPath", itemJsonPath);
         logLevel = getLogLevel(properties.getProperty("logLevel", logLevel.getName()));
+        dumpTraders = getBoolean(properties, "dumpTraders", dumpTraders);
+        dumpTradersCategoryId = getInt(properties, "dumpTradersCategoryId", dumpTradersCategoryId);
+        dumpTradersOutputPath = properties.getProperty("dumpTradersOutputPath", itemJsonPath);
         logger.setLevel(logLevel);
     }
 
@@ -49,6 +56,14 @@ public class ShopMod implements WurmServerMod, Initable, Configurable, ServerSta
         new ShopOpenAction(shopService, shopName, enableTokenAccess, enableMailboxAccess);
 
         logger.log(Level.INFO, String.format("Initialized shop '%s' (token access: %s, mailbox access: %s)", shopName, enableTokenAccess, enableMailboxAccess));
+
+        if (dumpTraders) {
+            try {
+                TraderItemExporter.dumpTraderItems(dumpTradersOutputPath, dumpTradersCategoryId);
+            } catch (Exception e) {
+                logger.log(Level.WARNING, "Failed to dump trader items", e);
+            }
+        }
     }
 
     /**
@@ -70,4 +85,13 @@ public class ShopMod implements WurmServerMod, Initable, Configurable, ServerSta
             return logLevel;
         }
     }
+
+    private int getInt(Properties properties, String key, int defaultValue) {
+        try {
+            return Integer.parseInt(properties.getProperty(key, Integer.toString(defaultValue)));
+        } catch (NumberFormatException e) {
+            logger.log(Level.WARNING, String.format("Invalid int for key '%s', defaulting to %d", key, defaultValue));
+            return defaultValue;
+        }
+    }
 }

src/main/java/mod/treestar/shopmod/util/TraderItemExporter.java

@@ -0,0 +1,89 @@
+package mod.treestar.shopmod.util;
+
+import com.wurmonline.server.Items;
+import com.wurmonline.server.creatures.Creature;
+import com.wurmonline.server.creatures.Creatures;
+import com.wurmonline.server.items.Item;
+import com.wurmonline.server.support.JSONArray;
+import com.wurmonline.server.support.JSONObject;
+
+import java.io.FileWriter;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * Utility to dump the current contents of all traders into a shop_items.json compatible array.
+ */
+public class TraderItemExporter {
+    private static final Logger logger = Logger.getLogger(TraderItemExporter.class.getName());
+
+    public static void dumpTraderItems(String outputPath, int categoryId) {
+        JSONArray out = new JSONArray();
+        AtomicInteger id = new AtomicInteger(1);
+
+        Set<Integer> seenTemplates = new HashSet<>();
+        for (Creature c : Creatures.getInstance().getCreatures()) {
+            if (c == null || !c.isTrader()) {
+                continue;
+            }
+            logger.log(Level.INFO, "Trader found");
+            try {
+                for (Item it : c.getAllItems()) {
+                    if (it.isCoin()) {
+                        continue; // skip currency
+                    }
+                    if(it.isBodyPart()) {
+                        continue; // Skip body parts
+                    }
+                    if(seenTemplates.contains(it.getTemplateId())) {
+                        continue;
+                    }
+                    seenTemplates.add(it.getTemplateId());
+                    JSONObject obj = new JSONObject();
+                    obj.put("id", id.getAndIncrement());
+                    obj.put("categoryId", categoryId);
+                    obj.put("name", it.getName());
+                    obj.put("description", it.getTemplate().getDescriptionLong());
+                    obj.put("image", "");
+                    JSONObject currency = new JSONObject();
+                    currency.put("type", "WurmBankCurrency");
+                    currency.put("ironAmount", it.getValue());
+                    obj.put("currency", currency);
+                    JSONObject handler = new JSONObject();
+                    handler.put("type", "ShopWurmItemPurchaseEffect");
+                    handler.put("itemTemplateId", it.getTemplateId());
+                    handler.put("ql", it.getQualityLevel());
+                    handler.put("rarity", (int) it.getRarity());
+                    obj.put("handler", handler);
+                    out.put(obj);
+                }
+            } catch (Exception e) {
+                logger.log(Level.WARNING, "Failed exporting items for trader " + c.getName(), e);
+            }
+        }
+
+        writeToFile(out, outputPath);
+    }
+
+    private static void writeToFile(JSONArray out, String outputPath) {
+        Path path = Paths.get(outputPath);
+        try {
+            if (path.getParent() != null) {
+                Files.createDirectories(path.getParent());
+            }
+            try (FileWriter fw = new FileWriter(path.toFile())) {
+                fw.write(out.toString(2));
+            }
+            logger.info("Dumped " + out.length() + " trader items to " + path.toAbsolutePath());
+        } catch (IOException e) {
+            logger.log(Level.WARNING, "Failed writing trader dump to " + outputPath, e);
+        }
+    }
+}