package com.github.dexecutor.executor;
   
   import java.util.concurrent.ExecutorService;
   
   import com.github.dexecutor.executor.graph.CyclicValidator;
   import com.github.dexecutor.executor.graph.LevelOrderTraversar;
   import com.github.dexecutor.executor.graph.Traversar;
   import com.github.dexecutor.executor.graph.Validator;
   import static com.github.dexecutor.executor.support.Preconditions.*;
  
  /**
   * <p>Configuration Object for Dexecutor framework. At a minimum it needs {@code ExecutorService} and {@code TaskProvider}, rest are optional and takes default values</p>
   * <p>This provides way to hook in your own {@code Validator} and {@code Traversar}</p>
   * 
   * @author Nadeem Mohammad
   *
   * @param <T>
   */
  public class DependentTasksExecutorConfig<T extends Comparable<T>> {
  	/**
  	 * executorService is the main platform on which tasks are executed
  	 */
  	private ExecutorService executorService;
  	/**
  	 * When it comes to task execution, task provider would be consulted to provide task objects for execution
  	 */
  	private TaskProvider<T> taskProvider;
  	/**
  	 * Validator for validating the consturcted graph, defaults to detecting Cyclic checks
  	 */
  	private Validator<T> validator = new CyclicValidator<T>();
  	/**
  	 * Traversar used to traverse the graph while printing it on a Writer
  	 */
  	private Traversar<T> traversar = new LevelOrderTraversar<T>();
  	/**
  	 * Construct the object with mandatory params, rest are optional
  	 * @param executorService
  	 * @param taskProvider
  	 */
  	public DependentTasksExecutorConfig(final ExecutorService executorService, final TaskProvider<T> taskProvider) {
  		this.executorService = executorService;
  		this.taskProvider = taskProvider;
  	}
  
  	void validate() {
  		checkNotNull(this.executorService, "Executer Service should not be null");
  		checkNotNull(this.taskProvider, "Task Provider should not be null");
  		checkNotNull(this.validator, "Validator should not be null");
  		checkNotNull(this.traversar, "Traversar should not be null");
  	}
  
  	ExecutorService getExecutorService() {
  		return executorService;
  	}
  
  	TaskProvider<T> getTaskProvider() {
  		return taskProvider;
  	}
  
  	Validator<T> getValidator() {
  		return validator;
  	}
  	/**
  	 * change the validator to that of specified
  	 * @param validator
  	 */
  	public void setValidator(final Validator<T> validator) {
  		this.validator = validator;
  	}
  	Traversar<T> getTraversar() {
  		return traversar;
  	}
  	/**
  	 * Change the traversar to that of specified
  	 * @param traversar
  	 */
  	public void setTraversar(final Traversar<T> traversar) {
  		this.traversar = traversar;
  	}
  }