content: /*
   * Copyright 2024-2025 the original author or authors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      https://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package com.alibaba.cloud.ai.graph;
  
  import com.alibaba.cloud.ai.graph.action.AsyncNodeActionWithConfig;
  import com.alibaba.cloud.ai.graph.exception.GraphStateException;
  import com.alibaba.cloud.ai.graph.internal.node.Node;
  import org.junit.jupiter.api.Test;
  
  import java.util.concurrent.CountDownLatch;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Executors;
  import java.util.concurrent.atomic.AtomicInteger;
  import java.util.concurrent.atomic.AtomicReference;
  
  import static org.junit.jupiter.api.Assertions.*;
  import static org.mockito.Mockito.*;
  
  
  public class NodeFactoryPatternTest {
  
      @Test
      public void testNodeFactoryCreatesNewInstances() throws Exception {
          Node.ActionFactory mockFactory = mock(Node.ActionFactory.class);
          AsyncNodeActionWithConfig mockAction1 = mock(AsyncNodeActionWithConfig.class);
          AsyncNodeActionWithConfig mockAction2 = mock(AsyncNodeActionWithConfig.class);
  
          when(mockFactory.apply(any(CompileConfig.class)))
                  .thenReturn(mockAction1)
                  .thenReturn(mockAction2);
  
          TestableCompiledGraph compiledGraph = new TestableCompiledGraph();
          compiledGraph.putNodeFactory("testNode", mockFactory);
  
          AsyncNodeActionWithConfig action1 = compiledGraph.getNodeAction("testNode");
          AsyncNodeActionWithConfig action2 = compiledGraph.getNodeAction("testNode");
  
          assertNotNull(action1, "First action should not be null");
          assertNotNull(action2, "Second action should not be null");
          assertNotSame(action1, action2, "Should return different instances each time");
  
          verify(mockFactory, times(2)).apply(any(CompileConfig.class));
      }
  
      @Test
      public void testConcurrentNodeCreation() throws Exception {
          AtomicInteger creationCount = new AtomicInteger(0);
          Node.ActionFactory mockFactory = mock(Node.ActionFactory.class);
  
          when(mockFactory.apply(any(CompileConfig.class))).thenAnswer(invocation -> {
              creationCount.incrementAndGet();
              AsyncNodeActionWithConfig mockAction = mock(AsyncNodeActionWithConfig.class);
              when(mockAction.toString()).thenReturn("Instance-" + creationCount.get());
              return mockAction;
          });
  
          TestableCompiledGraph compiledGraph = new TestableCompiledGraph();
          compiledGraph.putNodeFactory("testNode", mockFactory);
  
          ExecutorService executor = Executors.newFixedThreadPool(20);
          CountDownLatch latch = new CountDownLatch(50);
          AtomicInteger successCount = new AtomicInteger(0);
          AtomicReference<Exception> errorRef = new AtomicReference<>();
  
          for (int i = 0; i < 50; i++) {
              executor.submit(() -> {
                  try {
                      AsyncNodeActionWithConfig action = compiledGraph.getNodeAction("testNode");
                      assertNotNull(action, "Action should not be null");
                      successCount.incrementAndGet();
                  } catch (Exception e) {
                      errorRef.set(e);
                  } finally {
                      latch.countDown();
                  }
              });
          }
  
          latch.await();
          executor.shutdown();
  
          assertNull(errorRef.get(), "No exceptions should occur during concurrent access");
          assertEquals(50, successCount.get(), "All 50 calls should succeed");
          assertEquals(50, creationCount.get(), "Factory should be called 50 times");
      }
  
      private static class TestableCompiledGraph extends CompiledGraph {
  
          public TestableCompiledGraph() throws GraphStateException {
              super(createMinimalStateGraph(), CompileConfig.builder().build());
          }
  
          public void putNodeFactory(String nodeId, Node.ActionFactory factory) {
              this.nodeFactories.put(nodeId, factory);
          }
  
          private static StateGraph createMinimalStateGraph() throws GraphStateException {
              return new StateGraph();
          }
      }
  }
  