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.executor.MainGraphExecutor;
  
  import reactor.core.publisher.Flux;
  
  import java.util.Optional;
  import java.util.concurrent.atomic.AtomicReference;
  
  /**
   * A reactive graph execution engine based on Project Reactor. This class has been
   * refactored to use OOP principles (inheritance, polymorphism, encapsulation) for better
   * separation of concerns and improved readability.
   */
  public class GraphRunner {
  
  	private final CompiledGraph compiledGraph;
  
  	private final RunnableConfig config;
  
  	private final AtomicReference<Object> resultValue = new AtomicReference<>();
  
  	// Handler for main execution flow - demonstrates encapsulation
  	private final MainGraphExecutor mainGraphExecutor;
  
  	public GraphRunner(CompiledGraph compiledGraph, RunnableConfig config) {
  		this.compiledGraph = compiledGraph;
  		this.config = config;
  		// Initialize the main execution handler - demonstrates encapsulation
  		this.mainGraphExecutor = new MainGraphExecutor();
  	}
  
  	public Flux<GraphResponse<NodeOutput>> run(OverAllState initialState) {
  		return Flux.defer(() -> {
  			try {
  				GraphRunnerContext context = new GraphRunnerContext(initialState, config, compiledGraph);
  				// Delegate to the main execution handler - demonstrates polymorphism
  				return mainGraphExecutor.execute(context, resultValue);
  			}
  			catch (Exception e) {
  				return Flux.error(e);
  			}
  		});
  	}
  
  	public Optional<Object> resultValue() {
  		return Optional.ofNullable(resultValue.get());
  	}
  
  }
  