/* Datafile.cpp
 *
 * This is the cpp file for the datafile.
 *
 */

#include "Datafile.h"  // the header for the student class
#include <iomanip>     // for setw, setiosflags, etc...

// First constructor
// This sets up the elements of student.
Datafile::Datafile()
{
  // Initialize name to be empty and number to be -1
  number = -1;
  lastname = "";
  firstname = "";
  credits = -1;
  credits_term = -1;
  CGPA = 0;

  number_length = 8;
  lastname_length = 10;
  firstname_length = 10;
  credits_length = 3;
  CGPA_length = 4;
  recsize = number_length + lastname_length + firstname_length + credits_length + CGPA_length + 2;

}

// The destructor for the Student class.
// We didn't allocate any memory using the "new" keyword, so we
// don't have anything to do here.
Datafile::~Datafile()
{
}

// Accessors for the student number
long int Datafile::getNumber() const
{
  return number;
}

void Datafile::setNumber(long int newnumber)
{
  number = newnumber;
}

// Accessors for the student lastname
string Datafile::getLastName() const
{
  return lastname;
}

void Datafile::setLastName(string newlastname)
{
  lastname = newlastname;
}

// Accessors for the student firstname
string Datafile::getFirstName() const
{
  return firstname;
}

void Datafile::setFirstName(string newfirstname)
{
  firstname = newfirstname;
}

// Accessors for the student credits
int Datafile::getCredits() const
{
  return credits;
}

void Datafile::setCredits(int newcredits)
{
  credits = newcredits;
}

// Accessors for the student credits
int Datafile::getCredits_term() const
{
  return credits_term;
}

void Datafile::setCredits_term(int newcredits_term)
{
  credits_term = newcredits_term;
}

// Accessors for the student CGPA
float Datafile::getCGPA() const
{
  return CGPA;
}

void Datafile::setCGPA(float newCGPA)
{
  CGPA = newCGPA;
}

// seek to the appropriate record for reading
void Datafile::InputPositioningByRRN(int RRN, istream& input)
{
  input.seekg(RRN * recsize, ios::beg);
}

// seek to the appropriate position for writing
void Datafile::OutputPositioningByRRN(int RRN, ostream& output)
{
  output.seekp(RRN * recsize, ios::beg);
}

// modify the name of a student stored in a file 
void Datafile::ModifyBucketFile(int RRN, ostream& output, string newname)
{
   // seek to the appropriate student
   OutputPositioningByRRN(RRN,output);
   // seek to the name field
   output.seekp(number_length, ios::cur);
   // write the new name over the old one
   output << setw(lastname_length+firstname_length) << setiosflags(ios::left) << newname << endl;
}