from student import *

def readStudents(fname):
  """ fname is the file name,
  tries to read the information from the file and generate a list of students records,
  returns the list of student records if successful, retuns False otherwise """

  try:
    source = open(fname)

  except: # in case if file cannot be opened, terminate the function, return False
    return False

  studentsRecords = []
  student = source.readline() # read the first line from the file
  print("read:",student)

  # create a student record and append it to the list of students' records
  studentsRecords.append(makeStudent(student)) 
  
  for line in source: # read the rest of the lines from the file
    print("read:",line)
    studentsRecords.append(makeStudent(line)) # append to the list of records

  source.close()

  print("{0} student records are read".format(len(studentsRecords)))

  return studentsRecords

def writeStudents(fname,records):
  """ fname is the file name,
  tries to record all the students records into the file with name fname,
  if not possible, returns False"""

  try:
    out = open(fname,"w")

  except: # if not possible to open the file for writing, return False
    return False

  for record in records:
    print("{0} {1} {2}".format(record.getName(),record.getHours(),record.getQPoints()),file=out)

  out.close()


def main():

  # get the file name
  fname = input("Enter the name of input file:")
  

  records =  readStudents(fname)

  print(records)

  if records != False: 
    records.sort(key = Student.getGPA) # sorting records by getGPA method from Student class

    fname = input("Enter the name for output file:")

    writeStudents(fname,records)

    print("finished")
  else:
    print("something happened. The records were not read")
  

main()