//-------------------------------------------------------------------
// File   :application.C
// Author :Alicia Thorsen
// Course :CS1129
//
// Implementation of the Application class.
//-------------------------------------------------------------------

#include "application.h"
#include "course.h"
#include <iostream>
#include <fstream>
#include <cstdlib>
using namespace std;

//-------------------------------------------------------------------
// Precondition: filename contains the name of the input file.
// Postcondition: The catalog array contains all the information from the file.
//-------------------------------------------------------------------

void Application::readInputFile(string filename) {
  int i = 0, numOfStudents;
  string courseName, studentName;
  double numericGrade;
  ifstream fileIn(filename.c_str());

  // Check if file opened successfully.
  if (!fileIn.is_open()) {
    cerr << "Input file " << filename << " does not exist." << endl;
    exit(1);
  }

  // Read first course name from file if it exists.
  getline(fileIn, courseName);

  while (!fileIn.eof()) {
    // Set name of this course.
    catalog[i].setName(courseName);

    // Read number of students in this course.
    fileIn >> numOfStudents;
    fileIn.ignore();

    // For each student, read his/her name and grade.
    for (int j = 0; j < numOfStudents; ++j) {
      getline(fileIn, studentName);
      fileIn >> numericGrade;
      fileIn.ignore();

      // Add this student to the course.
      catalog[i].addStudent(studentName, numericGrade);
    }
    i++;
    // Read next course if it exists.
    getline(fileIn, courseName);
  }
  fileIn.close();

  // Save number of courses read.
  numOfCourses = i;
}

//-------------------------------------------------------------------
// Precondition: The catalog array contains all the course information.
// Postcondition: Letter grades are computed for all courses.
//-------------------------------------------------------------------

void Application::calcLetterGrades() {
  // Calculate letter grades for each course.
  for (int i = 0; i < numOfCourses; ++i)
    catalog[i].calcLetterGrades();
}

//-------------------------------------------------------------------
// Precondition: The catalog array contains all the course information.
// Postcondition: All student data for each course is written to an output file.
//-------------------------------------------------------------------

void Application::writeOutputFile() const {
  ofstream fileOut(OUTPUT_FILE_NAME);
  for (int i = 0; i < numOfCourses; ++i) 
    catalog[i].outputCourseData(fileOut);
  fileOut.close();
  cout << "Results written to " << OUTPUT_FILE_NAME << endl;
}