/*This code was generated using the UMPLE modeling language!
 Date of generation: 2008/07/29 14:51:25*/
/*This class drives: Topic*/

package University.core;

import java.util.*;
import University.*;
import University.json.*;

public class PrerequisiteReason {
  //Class datatypes

  //Class association variables
  private List<Topic> materialNeededBySuccessors;

  private Course successor;

  private Course prerequisite;

  //Registry of our system.
  UniversityRegistry registry = UniversityRegistry.getInstance();

  //Constructor
  public PrerequisiteReason(Course aSuccessor, Course aPrerequisite) {
    materialNeededBySuccessors = new ArrayList<Topic>();
    registry.add(materialNeededBySuccessors);

    successor = aSuccessor;
    successor.addSuccessorReason(this);

    prerequisite = aPrerequisite;
    prerequisite.addSuccessorReason(this);

  }

  public List<Topic> getMaterialNeededBySuccessors() {
    return materialNeededBySuccessors;
  }

  public Course getSuccessor() {
    return successor;
  }

  public Course getPrerequisite() {
    return prerequisite;
  }

  public Topic addMaterialNeededBySuccessor() {
    Topic newTopic;
    newTopic = new Topic();
    if (!materialNeededBySuccessors.contains(newTopic)) {
      registry.add(newTopic);
      materialNeededBySuccessors.add(newTopic);
    }
    return newTopic;
  }

  public Topic addMaterialNeededBySuccessor(Topic aMaterialNeededBySuccessor) {
    if (!materialNeededBySuccessors.contains(aMaterialNeededBySuccessor))
      materialNeededBySuccessors.add(aMaterialNeededBySuccessor);
    return aMaterialNeededBySuccessor;
  }

  /* This class does not drive Course and therefore sets the association unidirectionally.*/
  public void setSuccessor(Course aSuccessor) {
    successor = aSuccessor;
  }

  /* This class does not drive Course and therefore sets the association unidirectionally.*/
  public void setPrerequisite(Course aPrerequisite) {
    prerequisite = aPrerequisite;
  }

  public void delete() {
    //Delete all many ends first.
    for (Topic aTopic : materialNeededBySuccessors) {
      aTopic.delete();
    }
    materialNeededBySuccessors.clear();

    //Delete all 1 ends.
    successor.deleteSuccessorReason(this);
    prerequisite.deleteSuccessorReason(this);
  }

  public void deleteMaterialNeededBySuccessor(Topic aTopic) {

    if (materialNeededBySuccessors.contains(aTopic)) {
      materialNeededBySuccessors.remove(aTopic);

      //registry.removeObj(registry.getKey(aTopic));
    } else
    //Throw an UmpleException .. to be implemented.
    {
    }
  }

  public boolean areManyEndsNull() {
    if (materialNeededBySuccessors.size() == 0) {
      return true;
    } else
      return false;
  }

  /***********************************
   * Returns the attribute list along with the  
   * class ID in JSON format.
   ***********************************/
  public JSONObject getAttributes() throws JSONException {
    JSONObject obj = new JSONObject();
    obj.put("CLASS_ID", registry.getKey(this));
    return obj;
  }

}