package org.opentrafficsim.base.parameters.constraint;
   
   import java.util.LinkedHashSet;
   import java.util.Set;
   
   /**
    * Constraint containing multiple constraints.
    * <p>
    * Copyright (c) 2013-2024 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
   * BSD-style license. See <a href="https://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
   * </p>
   * @author <a href="https://github.com/averbraeck">Alexander Verbraeck</a>
   * @author <a href="https://github.com/peter-knoppers">Peter Knoppers</a>
   * @author <a href="https://github.com/wjschakel">Wouter Schakel</a>
   * @param <T> value type
   */
  public class MultiConstraint<T> implements Constraint<T>
  {
  
      /** Set of constraints. */
      private final Set<Constraint<? super T>> constraints;
  
      /** Message of the latest failed constrained. */
      private String failedConstraintMessage = null;
  
      /** String representation. */
      private final String stringRepresentation;
  
      /**
       * Creates a {@code MultiConstraint} from given constraints.
       * @param constraints constraints
       * @param <T> value type
       * @return {@code MultiConstraint}
       */
      @SafeVarargs
      public static final <T> MultiConstraint<T> create(final Constraint<? super T>... constraints)
      {
          Set<Constraint<? super T>> set = new LinkedHashSet<>();
          for (Constraint<? super T> constraint : constraints)
          {
              set.add(constraint);
          }
          return new MultiConstraint<>(set);
      }
  
      /**
       * Constructor.
       * @param constraints constraints
       */
      public MultiConstraint(final Set<Constraint<? super T>> constraints)
      {
          this.constraints = constraints;
          this.stringRepresentation = String.format("MultiConstraint [contains %d constraints]", this.constraints.size());
      }
  
      @Override
      public boolean accept(final T value)
      {
          for (Constraint<? super T> constraint : this.constraints)
          {
              if (!constraint.accept(value))
              {
                  this.failedConstraintMessage = constraint.failMessage();
                  return false;
              }
          }
          return true;
      }
  
      @Override
      public String failMessage()
      {
          if (this.failedConstraintMessage == null)
          {
              return "A constraint failed for parameter '%s'.";
          }
          // note that we do not synchronize, nor can't we be assured that after accept()=false, this method is (directly) invoked
          return "A constraint failed, most likely: " + this.failedConstraintMessage;
      }
  
      @Override
      public String toString()
      {
          return this.stringRepresentation;
      }
  
  }