fix(oracle): apply visible schema filter

agents/common/src/main/java/com/dbx/agent/DatabaseAgent.java

@@ -3,7 +3,10 @@ package com.dbx.agent;
 import java.sql.Connection;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
 
 public interface DatabaseAgent {
     void connect(ConnectParams params);
@@ -14,6 +17,14 @@ public interface DatabaseAgent {
 
     List<String> listSchemas();
 
+    default List<String> listSchemas(List<String> visibleSchemas) {
+        if (visibleSchemas == null) {
+            return listSchemas();
+        }
+        Set<String> visible = new HashSet<>(visibleSchemas);
+        return listSchemas().stream().filter(visible::contains).collect(Collectors.toList());
+    }
+
     List<TableInfo> listTables(String schema);
 
     default List<ObjectInfo> listObjects(String schema) {

agents/common/src/main/java/com/dbx/agent/JsonRpcServer.java

@@ -105,7 +105,7 @@ public final class JsonRpcServer {
         }
         if (AgentProtocol.METHOD_LIST_SCHEMAS.equals(method)) {
             switchCatalog(params);
-            return agent.listSchemas();
+            return agent.listSchemas(stringListOrNull(params, "visible_schemas"));
         }
         if (AgentProtocol.METHOD_LIST_TABLES.equals(method)) {
             switchCatalog(params);
@@ -289,6 +289,15 @@ public final class JsonRpcServer {
         return element.getAsString();
     }
 
+    private List<String> stringListOrNull(JsonObject object, String key) {
+        JsonElement element = object.get(key);
+        if (element == null || element instanceof JsonNull) {
+            return null;
+        }
+        Type listType = new TypeToken<List<String>>() {}.getType();
+        return gson.fromJson(element, listType);
+    }
+
     private static Integer intOrNull(JsonObject object, String key) {
         JsonElement element = object.get(key);
         if (element == null || element instanceof JsonNull) {