package ch.ffhs.webE.dao;

import java.util.ArrayList;
import java.util.List;

import org.hibernate.Session;
import org.hibernate.Transaction;

import ch.ffhs.webE.domain.Relationship;

import com.googlecode.s2hibernate.struts2.plugin.annotations.SessionTarget;
import com.googlecode.s2hibernate.struts2.plugin.annotations.TransactionTarget;

/**
 * Implements the Database Access Object for terms
 * 
 * @author Thomas Lahn
 */
public class RelationshipDAO
{
  /**
   * Database session
   */
  @SessionTarget
  Session session;

  /**
   * Database transaction
   */
  @TransactionTarget
  Transaction transaction;

  /**
   * Creates a list of all relationships
   * 
   * @return an ArrayList with all the relationshops - in case of a problem, an
   *         empty list is returned
   */
  @SuppressWarnings("unchecked")
  public List<Relationship> getList()
  {
    List<Relationship> relationship = null;
    try
    {
      relationship = this.session.createQuery("from Relationship").list(); //$NON-NLS-1$
    }
    catch (Exception e)
    {
      e.printStackTrace();
    }

    /*
     * If no relationship was checked, return an empty list to mitigate null
     * pointer exceptions
     */
    if (relationship == null)
    {
      relationship = new ArrayList<Relationship>();
    }

    return relationship;
  }

  /**
   * Executes the query to save the relationship
   * 
   * @param relationship
   *          Domain object to be saved
   * @return <code>true</code> if successful, <code>false</code> otherwise
   */
  public boolean saveOrUpdate(Relationship relationship)
  {
    try
    {
      relationship.setObjectId(relationship.getObjectId());
      this.session.saveOrUpdate(relationship);
      return true;
    }
    catch (Exception e)
    {
      this.transaction.rollback();
      e.printStackTrace();
      return false;
    }
  }

  /**
   * Delete a relationship
   * 
   * @param id
   *          Relationship ID
   */
  public void delete(int id)
  {
    try
    {
      Relationship relationship = (Relationship) this.session.get(
          Relationship.class, id);
      this.session.delete(relationship);
    }
    catch (Exception e)
    {
      this.transaction.rollback();
      e.printStackTrace();
    }
  }

  /**
   * Retrieves a relationship by ID
   * 
   * @param id
   *          Term ID
   * @return The relationship with this <var>id</var>
   */
  public Relationship getById(int id)
  {
    Relationship relationship = null;

    try
    {
      relationship = (Relationship) this.session.get(Relationship.class, id);
    }
    catch (Exception e)
    {
      e.printStackTrace();
    }

    return relationship;
  }
}