Updates student records, calculates GPAs, and provides an overview sheet for school admin

StudentData.gs

function updateStudentData(){
  //Opens the student grades files
  var file = DriveApp.getFileById('1GK_h7felFYckgK4J7bdpMhJE_CTO1wS_1_120fnQIXA');
  var studentDataTemplate = DriveApp.getFileById('1COq76_rQzGUvme5FPKj_Rkf4c461P7MRozM6TuMZrUw');
  
  //Opens the folder to save the data in or creates the folder
  var folderIt = DriveApp.getFoldersByName('Student Data from Parse');
  if (folderIt.hasNext()){
    var folder = folderIt.next();
  }
  else{
    var folder = DriveApp.createFolder('Student Data from Parse');
  }
  
  var todayDate = new Date();
  var today = Utilities.formatDate(todayDate, 'UTC+01:00', "yyyy-MM-dd");
  
  //Gets a template file with pre-configured pie chart
  var newFile = file.makeCopy(today+' Student Data', folder);
  var newSheet = SpreadsheetApp.open(newFile).getSheets()[0];
  
  //Gets student data
  var sheet = SpreadsheetApp.getActiveSheet();
  var studentData = sheet.getDataRange();
  
  //Set up varables
  var grade = '';
  var gradeSum = 0;
  var totalGrades = 0
  var className = '';
  var percentGrade = 0;
  var classNames = [];
  var percentGrades = [];
  var totalRows = sheet.getMaxRows();
  var currentStudent = sheet.getRange(2, 2).getValue();
  
  //Goes through the sheet
  for (var i = 2; i < totalRows+1; i++){
    var currentRow = sheet.getRange(i, 2, 1, 8).getValues();
    
    //If the student name is the same, adds the class name and percent grade to the array
    if (currentStudent == currentRow[0][0]){
      grade = currentRow[0][1];
      className = currentRow[0][4];
      classNames.push(className);
      percentGrade = currentRow[0][3];
      percentGrades.push(percentGrade);
      
      //Adds to the grade total and counts number of grades given to calculate the current grade
      var numberGrade = checkGrade(currentRow[0][2]);
      if (numberGrade < 100){
        gradeSum = gradeSum + numberGrade
        totalGrades++
      }
    }
    
    //If the student name is differnet because the file has moved to the next student
      else{
        if (i > 2){
          //Calculates the GPA and adds it to the GPA tracking sheet
          var GPA = (Math.round((gradeSum / totalGrades)*100)/100);
          newSheet.appendRow([currentStudent,grade,GPA]);
          
          //Opens the student records and adds the grades to them
          var studentFileIt = DriveApp.getFilesByName('Student Data for '+currentStudent);
          if (studentFileIt.hasNext()){
            var studentFile = studentFileIt.next();
            var studentDataSS = SpreadsheetApp.open(studentFile);
            
          }
          else{
            var studentFile = studentDataTemplate.makeCopy('Student Data for '+currentStudent, folder);
            var studentDataSS = SpreadsheetApp.open(studentFile);
            studentDataSS.appendRow(classNames);
          }
          
          studentDataSS.getSheets()[0].appendRow(percentGrades);
          Logger.log(studentDataSS.getUrl());
         
          
        //and then resets the varables
        currentStudent = currentRow[0][0]
        gradeSum = 0
        totalGrades = 0
        var classNames = [];
        var percentGrades = [];
        className = currentRow[0][4];
        classNames.push(className);
        percentGrade = currentRow[0][3];
        percentGrades.push(percentGrade);
        var numberGrade = checkGrade(currentRow[0][2]);
      if (numberGrade < 100){
        gradeSum = gradeSum + numberGrade
        totalGrades++
        }
      }
    }
  }
}

function checkGrade(grade){
      if (grade == 'A'){
        return 4
      }
      if (grade == 'B'){
        return 3
       }
      if (grade == 'C'){
        return 2
      }
      if (grade == 'D'){
        return 1
      }
      if (grade == 'F'){
        return 0
      }
      else{
        return 100
      }
    }