// ******************************************************************************
   //
   // Title:       Force Field X.
   // Description: Force Field X - Software for Molecular Biophysics.
   // Copyright:   Copyright (c) Michael J. Schnieders 2001-2025.
   //
   // This file is part of Force Field X.
   //
   // Force Field X is free software; you can redistribute it and/or modify it
  // under the terms of the GNU General Public License version 3 as published by
  // the Free Software Foundation.
  //
  // Force Field X is distributed in the hope that it will be useful, but WITHOUT
  // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  // FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
  // details.
  //
  // You should have received a copy of the GNU General Public License along with
  // Force Field X; if not, write to the Free Software Foundation, Inc., 59 Temple
  // Place, Suite 330, Boston, MA 02111-1307 USA
  //
  // Linking this library statically or dynamically with other modules is making a
  // combined work based on this library. Thus, the terms and conditions of the
  // GNU General Public License cover the whole combination.
  //
  // As a special exception, the copyright holders of this library give you
  // permission to link this library with independent modules to produce an
  // executable, regardless of the license terms of these independent modules, and
  // to copy and distribute the resulting executable under terms of your choice,
  // provided that you also meet, for each linked independent module, the terms
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  // exception statement from your version.
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  // ******************************************************************************
  package ffx.potential.terms;
  
  import ffx.potential.bonded.BondedTerm;
  import ffx.potential.bonded.Torsion;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.List;
  import java.util.logging.Logger;
  
  /**
   * Restrain-Torsion potential energy term using {@link ffx.potential.bonded.Torsion} instances.
   * Method names are specific to restrain torsions for clarity.
   */
  public class RestrainTorsionPotentialEnergy extends EnergyTerm {
  
    private static final Logger logger = Logger.getLogger(RestrainTorsionPotentialEnergy.class.getName());
  
    /**
     * Internal list of Torsion instances for restrain torsions.
     */
    private final List<Torsion> restrainTorsions = new ArrayList<>();
  
    /**
     * Create a RestrainTorsionPotentialEnergy with the provided name.
     *
     * @param name Name for this term.
     */
    public RestrainTorsionPotentialEnergy(String name) {
      super(name);
    }
  
    /**
     * Create a RestrainTorsionPotentialEnergy with the provided name and force group.
     *
     * @param name       Name for this term.
     * @param forceGroup Integer force group identifier.
     */
    public RestrainTorsionPotentialEnergy(String name, int forceGroup) {
      super(name, forceGroup);
    }
  
    /**
     * Create a RestrainTorsionPotentialEnergy initialized with a list of torsions and force group.
     *
     * @param name             Name for this term.
     * @param forceGroup       Force group identifier.
     * @param restrainTorsions List of Torsion instances to add (null-safe).
     */
    public RestrainTorsionPotentialEnergy(String name, int forceGroup, List<Torsion> restrainTorsions) {
      super(name, forceGroup);
      if (restrainTorsions != null) {
        Collections.sort(restrainTorsions);
        this.restrainTorsions.addAll(restrainTorsions);
        logger.info(String.format("  Restrain Torsions:                   %10d", getNumberOfRestrainTorsions()));
      }
    }
  
    /**
     * {@inheritDoc}
     */
   @Override
   public int getNumberOfTerms() {
     return getNumberOfRestrainTorsions();
   }
 
   /**
    * {@inheritDoc}
    */
   @Override
   public BondedTerm[] getBondedTermsArray() {
     return getRestrainTorsionArray();
   }
 
   /**
    * Create a RestrainTorsionPotentialEnergy initialized with a collection of torsions.
    *
    * @param name             Name for this term (may be null).
    * @param restrainTorsions Collection of Torsion instances to add (null-safe).
    */
   public RestrainTorsionPotentialEnergy(String name, Collection<Torsion> restrainTorsions) {
     super(name);
     if (restrainTorsions != null) {
       this.restrainTorsions.addAll(restrainTorsions);
     }
   }
 
   /**
    * Add a single restrain torsion.
    *
    * @param torsion Torsion to add (ignored if null).
    * @return true if added.
    */
   public boolean addRestrainTorsion(Torsion torsion) {
     if (torsion == null) {
       return false;
     }
     return restrainTorsions.add(torsion);
 
   }
 
   /**
    * Add an array of restrain torsions.
    *
    * @param torsions Array of Torsion instances to add.
    * @return true if added.
    */
   public boolean addRestrainTorsions(Torsion[] torsions) {
     if (torsions == null) {
       return false;
     }
     Collections.addAll(this.restrainTorsions, torsions);
     return true;
   }
 
   /**
    * Add a list of restrain torsions.
    *
    * @param torsions List of Torsion instances to add.
    * @return true if added.
    */
   public boolean addRestrainTorsions(List<Torsion> torsions) {
     if (torsions == null) {
       return false;
     }
     this.restrainTorsions.addAll(torsions);
     return true;
   }
 
   /**
    * Remove a restrain torsion.
    *
    * @param torsion Torsion to remove (ignored if null).
    * @return true if removed.
    */
   public boolean removeRestrainTorsion(Torsion torsion) {
     if (torsion == null) {
       return false;
     }
     return restrainTorsions.remove(torsion);
   }
 
   /**
    * Get a restrain torsion at an index.
    *
    * @param index Index.
    * @return Torsion.
    * @throws IndexOutOfBoundsException if invalid index.
    */
   public Torsion getRestrainTorsion(int index) {
     return restrainTorsions.get(index);
   }
 
   /**
    * Get an unmodifiable view of restrain torsions.
    *
    * @return List of Torsion.
    */
   public List<Torsion> getRestrainTorsions() {
     return Collections.unmodifiableList(restrainTorsions);
   }
 
   /**
    * Get an array of restrain torsions.
    *
    * @return Array of Torsion.
    */
   public Torsion[] getRestrainTorsionArray() {
     return restrainTorsions.toArray(new Torsion[0]);
   }
 
   /**
    * Get the number of restrain torsions.
    *
    * @return Number of restrain torsions.
    */
   public int getNumberOfRestrainTorsions() {
     return restrainTorsions.size();
   }
 
   @Override
   public String toPDBString() {
     if (getNumberOfRestrainTorsions() <= 0) {
       return "";
     }
     return String.format("REMARK   3   %s %g (%d)\n", "RESTRAIN TORSION           : ", getEnergy(), getNumberOfRestrainTorsions());
   }
 
   @Override
   public String toString() {
     return String.format("  %s %20.8f %12d %12.3f\n", "Restrain Torsion  ",
         getEnergy(), getNumberOfRestrainTorsions(), getTime());
   }
 
   /**
    * Log the details of Restrain Torsion interactions.
    */
   @Override
   public void log() {
     if (getNumberOfRestrainTorsions() <= 0) {
       return;
     }
     logger.info("\n Restrain Torsion Interactions:");
     for (Torsion torsion : getRestrainTorsions()) {
       logger.info(" Restrain Torsion \t" + torsion.toString());
     }
   }
 }