package ejava.examples.webtier.bl;
   
   import java.util.List;
   
   import java.util.Map;
   
   import org.slf4j.Logger;
   import org.slf4j.LoggerFactory;
   
  import ejava.examples.webtier.bo.Grade;
  import ejava.examples.webtier.bo.Student;
  import ejava.examples.webtier.dao.StudentDAO;
  
  public class RegistrarImpl implements Registrar {
      Logger logger = LoggerFactory.getLogger(RegistrarImpl.class);
      private static final String NEW_STUDENT_QUERY = "getNewStudents";
      private static final String GRAD_QUERY = "getGraduatingStudents";
      
      private StudentDAO dao;
      
      public void setStudentDAO(StudentDAO dao) {
          this.dao = dao;
      }
  
      public Student addStudent(Student student) throws RegistrarException {
          try {
              return dao.create(student);
          }
          catch (Throwable th) {
              throw new RegistrarException(th);
          }
      }
  
      public Student completeCourse(Student student, Grade grade)
              throws RegistrarException {
          try {
              student.getGrades().add(grade);            
              return dao.update(student);
          }
          catch (Throwable th) {
              throw new RegistrarException(th);
          }
      }
  
      public Student dropStudent(Student student) throws RegistrarException {
          try {
              //do some checking around.....
              //if okay
              return dao.remove(student);
          }
          catch (Throwable th) {
              throw new RegistrarException(th);
          }
      }
  
      public List<Student> getStudents(int index, int count)
          throws RegistrarException {
          try {
              return dao.find(index, count);
          }
          catch (Throwable th) {
              throw new RegistrarException(th);
          }
      }
      
      public List<Student> getGraduatingStudents(int index, int count)
              throws RegistrarException {
          try {
              return dao.find(GRAD_QUERY, null, index, count);
          }
          catch (Throwable th) {
              throw new RegistrarException(th);
          }
      }
  
      public List<Student> getNewStudents(int index, int count)
              throws RegistrarException {
          try {
              return dao.find(NEW_STUDENT_QUERY, null, index, count);
          }
          catch (Throwable th) {
              throw new RegistrarException(th);
          }
      }
  
      public Student getStudent(long id) throws RegistrarException {
          try {
              return dao.get(id); 
          }
          catch (Throwable th) {
              throw new RegistrarException(th);
          }
      }
  
      public List<Student> getStudents(
              String queryName, Map<String, Object> params, int index, int count) 
              throws RegistrarException {
          try {
              return dao.find(queryName, params, index, count);
         }
         catch (Throwable th) {
             throw new RegistrarException(th);
         }
     }
 }