package net.bmahe.genetics4j.core.spec;
   
   import java.util.Objects;
   
   import net.bmahe.genetics4j.core.selection.RouletteWheelSelectionPolicyHandler;
   import net.bmahe.genetics4j.core.spec.ImmutableEAExecutionContext.Builder;
   
   /**
    * Defines multiple factory and helper methods to create and manage EAExecutionContexts
   */
  public class EAExecutionContexts {
  
  	private EAExecutionContexts() {
  	}
  
  	public static <T extends Comparable<T>> Builder<T> standard() {
  		return ImmutableEAExecutionContext.builder();
  	}
  
  	/**
  	 * Enrich an EAExecutionContext builder based on the knowledge of the fitness function returning a scalar value.
  	 * <p>This will enrich it with additional implementations for selecting, combining and mutating individuals.
  	 * 
  	 * @param <T>     Type of the fitness measurement
  	 * @param builder
  	 * @return Enriched EAExecutionContext builder
  	 */
  	public static <T extends Number & Comparable<T>> Builder<T> enrichForScalarFitness(final Builder<T> builder) {
  		Objects.requireNonNull(builder);
  
  		builder.addSelectionPolicyHandlerFactories(
  				gsd -> new RouletteWheelSelectionPolicyHandler<T>(gsd.randomGenerator()));
  		return builder;
  	}
  
  	/**
  	 * Create an EAExecutionContext builder based on the knowledge of the fitness function returning a scalar value.
  	 * <p>This will enrich it with additional implementations for selecting, combining and mutating individuals.
  	 * 
  	 * @param <T>
  	 * @return
  	 */
  	public static <T extends Number & Comparable<T>> Builder<T> forScalarFitness() {
  
  		final Builder<T> builder = ImmutableEAExecutionContext.builder();
  		return enrichForScalarFitness(builder);
  	}
  }