/*
COPYRIGHT (C) 2019 Savannah Rimmele (smr165) All rights reserved.
CSI Assignment 5
Author. Savannah Rimmele
        smr165@zips.uakron.edu
Version. 1.01 07.09.2017
Purpose: This program is to express the use of basic input, output, flow of control, calculation, iteration, and uses functions.
Using these it will calculate a grade for a specified amount of exercises within a range of points, any inputs will be validated.
*/
/*
Functional Decomposition:
Level 1:
1. Determine the subject
2. Calculate the amount of exercises
3. Calculate the score on an exercise
4. Calculate the amount of possible points on an exercise
5. Calculate the actual total points scored
6. Calculate the actual amount of total points possible
7. Calculate the grade percent
8. Determine the letter grade
9. Get various entries
10. Display

Level 2:
1. Determine the subject
    1.1 Get the subject entry
    1.2 Validate subject entries
2. Calculate the amount of exercises
    2.1 Get the exercise entries
    2.2 Validate the amount of exercises
3. Calculate the score on an exercise
    3.1 Get the score entries
    3.2 Validate these entries
4. Calculate the amount of possible points on an exercise
    4.1 Get the entries for possible points
    4.2 Validate these entries
5. Calculate the actual total points scored
    5.1 Set total points scored to the addition of the amount of points scored for each exercise
6. Calculate the actual amount of total points possible
    6.1 Set total points possible to the addition of the amount of points possible for each exercise
7. Calculate the grade percent
    7.1 Set grade percent to the total score received divided by the total points possible
        multiplied by 100.
8. Determine the letter grade
    8.1 Set A within the range of 93 and 100
    8.2 Set A- within the range of 90 and 92.99
    8.3 Set B+ within the range of 97 and 89.99
    8.4 Set B within the range of 83 and 86.99
    8.5 Set B- within the range of 80 to 82.99
    8.6 Set C+ within the range of 77 to 79.99
    8.7 Set C within the range of 73 to 76.99
    8.8 Set C- within the range of 70 to 72.99
    8.9 Set D+ within the range of 67 to 69.99
    8.10 Set D within the range of 63 to 66.99
    8.11 Set D- within the range of 60 to 62.99
    8.12 Set F to anything below 60.
9. Get various entries
    9.1 Continue adding entries
    9.2 Each entry will calculate a different percent grade
10. Display
    10.1 Print the subject choices menu
    10.2 Print the amount of exercises
    10.3 Print the amount of scored points on an exercise
    10.4 Print the amount of possible points for an exercise
    10.5 Print the score received out of the total possible points
    10.6 Print the percent grade
    10.7 Print the letter grade
*/

#include <iostream>
#include <iomanip>
#include <limits>
#include <cstdlib> //for rand and srand
#include <ctime>
#include <fstream>
#include <sstream>
#include <cstring>
using std::cout;
using std::cin;
using std::endl;
using std::string;
using std::ofstream;
using std::ifstream;
using std::stringstream;

bool validateInput(int, int, int, string & ); //Control for validation
int getSubject();
int getExercise();
int getExerciseReceived(int, int);
int getExerciseTotal(int);
void printPercentGrade(double &, double &);
void getGrades(int, double &, double &, double &, double &, double &, double &, double &, double &, double & , double &, double &, double &);
void printSubjectGrades( double &, double &, double &, double &, double &, double &, double &, double &, double &, double &);
string subjectToString(int);
int getArraySize(int []);
void bubbleSort(int [], int);
double mean(int [], int);
int mode(int [], int);
int median(int [], int);
void getArr();
void password();
int getArrSize(string &);

int main()
{
    password();
    ofstream oStream;
    oStream.open( "Subject.txt", std::ios::app);
    double earnedBiology = 0, totalBiology =0, earnedSociology = 0, totalSociology = 0,
        earnedGeography = 0, totalGeography = 0, earnedCalculus = 0, totalCalculus = 0,
        earnedPhysics = 0, totalPhysics = 0;
while(true)
{
    int subject = getSubject(); //Get the user's choice of subject
    if (subject == 6)
    {
        printSubjectGrades(earnedBiology, totalBiology, earnedSociology, totalSociology, earnedCalculus, totalCalculus, earnedGeography, totalGeography, earnedPhysics, totalPhysics);
        oStream.close(); //file closes when quit is chosen
        getArr();
        cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
        password();
        return 0;
    }

    oStream << subjectToString(subject); //displays subject string inside of file
    int numberExercises = getExercise(); //between 1 and 10
    int countup = 0;
    double scoreReceived = 0;
    double totalPointsPossible = 0;
    while (countup < numberExercises)
    {
     int exerciseTotal = getExerciseTotal(countup +1);
     int exerciseReceived = getExerciseReceived(countup +1, exerciseTotal);
     oStream << exerciseReceived << " " << exerciseTotal << " ";
      cout << "\n\n";
     scoreReceived = exerciseReceived + scoreReceived;
     totalPointsPossible = totalPointsPossible + exerciseTotal;
     countup ++;

    }
    oStream << "\n";
   getGrades(subject, scoreReceived, totalPointsPossible, earnedBiology, totalBiology, earnedSociology, totalSociology, earnedCalculus, totalCalculus, earnedGeography, totalGeography, earnedPhysics, totalPhysics);
   printPercentGrade(scoreReceived, totalPointsPossible);
}
}
//precondition: validates the input
// postcondition: returns true or displays the invalid message.
bool validateInput(int subject, int num1, int num2, string & message)
{
    if (subject >= num1 && subject <= num2)
    {
        return true;
    }
    else
    {
      cout << message << endl;
      return false;
    }
}

int getSubject()
// Menu to choose which subject the exercises were for
//precondition: call when subject menu is to be displayed
// postcondition: return an int for the user's choice
{
int subject;
bool controlFlag = true;
do
{
    string msg("The valid choices are 1 through 6.");       //Displays when an invalid integer is given
        cout << "Please choose a subject from the menu: \n"
        << "1. Biology \n"
        << "2. Sociology \n"
        << "3. Geography \n"
        << "4. Calculus \n"
        << "5. Physics \n"
        << "6. Quit \n\n";
    cout << "Your choice: \n";
    cin >> subject;
    controlFlag = !validateInput(subject, 1, 6, msg);
}
while (controlFlag);
return subject;
}

int getExercise()
//precondition: Use to generate a random integer
// postcondition: Displays a random integer between 1 and 10.
 {
    int numberExercises;
    srand(time(0));
    numberExercises = 1 + rand() % 10;
    cout << "How many exercises to input? " << numberExercises;
    cout << "\n\n";
    return numberExercises;
 }

int getExerciseReceived(int exerciseNum, int exerciseTotal)
// precondition: determines the score received for each exercise.
// postcondition: Displays the input given by the user.
//                Validates the user's input between a specified range
{
    bool controlFlag = true;
    int exerciseReceived;
    do
    {
    string msg("The valid choices are 1 through 100 and must be within the total points possible.");
    cout << "Score Received for exercise " << exerciseNum << ": " ;
     cin >> exerciseReceived;
     if (cin.fail() || exerciseReceived < 1 || exerciseReceived > exerciseTotal)
     {
         cout << msg << endl;
         cin.clear();
         cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
     }
     else
     {
         controlFlag = false;
     }
    }
    while (controlFlag);
    return exerciseReceived;
}

int getExerciseTotal(int exerciseNum)
// precondition: Determines the amount amount of total points possible for each exercise
// postcondition: Displays the input given by user
//                Validates the input between the specified range
{
    bool controlFlag = true;
    int exerciseTotal;
    do
    {
     string msg("The valid choices are 1 through 100.");
     cout << "Total points possible for exercise " << exerciseNum << ": " ;
     cin >> exerciseTotal;
     if(cin.fail() || exerciseTotal < 1 || exerciseTotal > 100)
     {
        cout << msg << endl;
        cin.clear();
        cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
     }
     else
     {
         controlFlag = false;
     }
    }
    while (controlFlag);
    return exerciseTotal;
}

void printPercentGrade(double & scoreReceived, double & totalPointsPossible)
//precondition: Calculates the percent grade and determines the matching letter grade
// postcondition: Displays the grade percentage
//                Uses percentage to determine letter grade
//                Displays the Letter Grade
{
    double percentGrade = 0;
    percentGrade = totalPointsPossible ? ((scoreReceived / totalPointsPossible) * 100) : 100;
    cout.precision(4);
    cout << "Your total is " << scoreReceived << " out of " << totalPointsPossible << ", or " << percentGrade << "%.\n";
    if (percentGrade >= 93)
    {
        cout << "Your letter grade is A.";
    }
    else if (percentGrade >= 90 && percentGrade <= 92.99)
    {
        cout << "Your letter grade is A-.";
    }
    else if (percentGrade >= 87  && percentGrade <= 89.99)
    {
        cout << "Your letter grade is B+.";
    }
    else if (percentGrade >= 83 && percentGrade <= 86.99)
    {
        cout << "Your letter grade is B.";
    }
    else if (percentGrade >= 80 && percentGrade <= 82.99)
    {
        cout << "Your letter grade is B-.";
    }
    else if (percentGrade >= 77 && percentGrade <= 79.99)
    {
        cout << "Your letter grade is C+.";
    }
    else if (percentGrade >= 73 && percentGrade <= 76.99)
    {
        cout << "Your letter grade is C.";
    }
    else if (percentGrade >= 70 && percentGrade <= 72.99)
    {
        cout << "Your letter grade is C-.";
    }
    else if (percentGrade >= 67 && percentGrade <= 69.99)
    {
        cout << "Your letter grade is D+.";
    }
    else if (percentGrade >= 63 && percentGrade <= 66.99)
    {
        cout << "Your letter grade is D.";
    }
    else if (percentGrade >= 60 && percentGrade <= 62.99)
    {
        cout << "Your letter grade is D-.";
    }
    else
    {
        cout << "Your letter grade is F.";
    }
    cout << endl << endl;
}

void getGrades(int subject, double & scoreReceived, double & totalPointsPossible, double & earnedBiology, double & totalBiology, double & earnedSociology, double & totalSociology, double & earnedCalculus, double & totalCalculus, double & earnedGeography, double & totalGeography, double & earnedPhysics, double & totalPhysics )
// precondition: Calculates the total sum for each subject
// postcondition: Displays the sum for each subject

{
  switch(subject)
  {
  case 1:
    earnedBiology += scoreReceived;
    totalBiology += totalPointsPossible;
    break;
  case 2:
    earnedSociology += scoreReceived;
    totalSociology += totalPointsPossible;
    break;
  case 3:
    earnedGeography += scoreReceived;
    totalGeography += totalPointsPossible;
    break;
  case 4:
    earnedCalculus += scoreReceived;
    totalCalculus += totalPointsPossible;
    break;
  case 5:
    earnedPhysics += scoreReceived;
    totalPhysics += totalPointsPossible;
    break;
  default:
    cout << "Something broke.";
  }
}

void printSubjectGrades( double & earnedBiology, double & totalBiology, double & earnedSociology, double & totalSociology, double & earnedCalculus, double & totalCalculus, double & earnedGeography, double & totalGeography, double & earnedPhysics, double & totalPhysics)
// precondition: Calculates the percent grade for each subject and displays the matching letter grade
// postcondition: Displays each subject
//                Displays the percent grade
//                Displays the letter grade
{

    cout << "For Biology: \n";
    printPercentGrade(earnedBiology, totalBiology);

    cout << "For Sociology: \n";
    printPercentGrade(earnedSociology, totalSociology);

    cout << "For Geography: \n";
    printPercentGrade(earnedGeography, totalGeography);

    cout << "For Calculus: \n";
    printPercentGrade(earnedCalculus, totalCalculus);

    cout << "For Physics: \n";
    printPercentGrade(earnedPhysics, totalPhysics);
}

string subjectToString(int subject)
//precondition: Changes the numerical values of the subjects to the specific string
//postcondition: Displays the subjects as a string rather than a value
{
switch(subject)
    {
        case 1: return "Biology ";
        case 2: return "Sociology ";
        case 3: return "Geography ";
        case 4: return "Calculus ";
        case 5: return "Physics ";
    }
    return "";
}

int getArraySize(int arr[])
//precondition: Calculates the size of the array when it is not zero.
//postcondition: displays the array with determined size, without displaying zeros where points were not entered.
{
    int size = 0;
    while(arr[size] != 0)
    {
        ++size;
    }
    return size;
}

void bubbleSort(int arr[], int size)
// precondition: Sorts the array numerically by comparing adjacent integers
// postcondition: Displays the array in order, numerically.
{
     bool swap;
    int temp;
    do
    {
        swap = false;
        for(int count = 0; count < (size - 2); count += 2)
        {
            if(arr[count] > arr[count + 2])
            {
               temp = arr[count];
               arr[count] = arr[count + 2];
               arr[count + 2] = temp;
               temp = arr[count + 1];
               arr[count + 1] = arr[count + 3];
               arr[count + 3] = temp;
               swap = true;
            }
        }
    }
    while (swap);
}

double mean(int arr[], int size)
// precondition: Calculates the average for a specific subject
//               Adds up all of the integers and divides by the size of the array
// postcondition: Displays the mean of each subjects
{

    if(size <= 1)
    {
        return 0.0;
    }

    int total = 0;
    for(int i = 0; i < size; i += 2)
    {
        total += arr[i];
    }
    return (double)total/(size / 2);
}

int median(int arr[], int size)
//precondition: Uses the size of the sorted array to determine the center of the array, then takes the floor of that.
//postcondition: Displays the average of each subject
{
    if(size <= 1)
    {
        return 0;
    }

   return arr[(size / 2) - 1];
}

int mode(int arr[], int size)
//precondition: Calculates which number is present the most in the array
//postcondition: Displays the mode of each subject
{
    if(size <= 1)
    {
        return 0;
    }

int mode = arr[0], modeCount = 1, curCount = 1;
for(int i = 2; i < size; i += 2)
{
    if(arr[i] == arr[i - 2])
    {
        ++curCount;
        if(curCount > modeCount)
        {
            modeCount = curCount;
            mode = arr[i];
        }
    }
    else
    {
        curCount = 1;
    }
}
return mode;
}

void getArr()
//precondition: opened file numbers are put into an array
//postcondition: Array is sorted in ascending order
//               The mean, median, and mode is displayed
{
    ifstream iStream;
    int *subjectGrades[5];

    for (int i = 1; i < 6; i++)
    {
        iStream.open("Subject.txt");
        string subFile, scores;
        string subjectStr = subjectToString(i);
        int arrSize = getArrSize(subjectStr);
        subjectGrades[i - 1] = new int [arrSize];
        int count = 0;

        while(!getline(iStream, subFile, ' ').eof())
        {
            getline(iStream, scores, '\n');
            subFile += ' ';
            if(subFile == subjectStr)
            {
                stringstream scoreStream;
                scoreStream << scores;
                while(!scoreStream.eof() && count < 25)
                {
                    scoreStream >> subjectGrades[i - 1][count++];
                }
            }
            else
            {
                iStream.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
            }
        }
        iStream.clear();
        iStream.close();
        bubbleSort(subjectGrades[i - 1], arrSize);

        cout << subjectStr << " mean is " << mean(subjectGrades[i - 1], arrSize) << ", the mode is "
             << mode(subjectGrades[i - 1], arrSize) << ", the median is " << median(subjectGrades[i  -1], arrSize) << "\n\n";

    }
}

void password()
//precondition: Prompts user for a password
//postcondition: Password is encrypted
//               Password at the end must be the same as the beginning
{
    const int KEY = 256;
    static char pass[KEY] = {'\0'};
    char inputPass[KEY];
    cout << "Enter the password. \n";

    cin.getline(inputPass, KEY - 1, '\n');
    for(int i = 0; i < (KEY - 1); ++i)
    {
      if(inputPass[i] + KEY > 256)
      {
      inputPass[i] = 32 + ((inputPass[i] + KEY) - 127);
      }
      else
      {
        inputPass[i] = (inputPass[i] + KEY);
      }
    }
    if(pass[0] == '\0')
    {
        strcpy(pass, inputPass);
    }
    else
    {
      if(!strcmp(inputPass, pass))
        cout << "Password correct. \n";
      else
        cout << "Incorrect Password. \n";

    }
}

int getArrSize(string & subject)
{
    ifstream is("Subject.txt");
    string currentLine;
    int size = 0;
    while(!getline(is, currentLine, '\n').eof() && size < 25)
    {
        if(subject == currentLine.substr(0, currentLine.find(' ') + 1))
        {
            int spaceIndex = currentLine.find(' ');
            string grades = currentLine.substr(spaceIndex);
            stringstream currentLineStream(currentLine);
            string dummy;
            while(!getline(currentLineStream, dummy, ' ').eof() && size < 25)
            {
                ++size;
            }
            --size;
        }
        is.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
    }
    return size;
}