main.cpp

#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <iomanip>
using namespace std;

struct Subject
{
  string name;
  int progress; // progress in percentage
};

// Function to load subjects from file
vector<Subject> loadSubjects()
{
  vector<Subject> subjects;
  ifstream file("study_data.txt");

  if (file.is_open())
  {
    Subject s;
    while (file >> ws && getline(file, s.name, ','))
    {
      file >> s.progress;
      file.ignore(); // ignore newline
      subjects.push_back(s);
    }
    file.close();
  }
  return subjects;
}

// Function to save subjects to file
void saveSubjects(const vector<Subject> &subjects)
{
  ofstream file("study_data.txt");
  for (auto &s : subjects)
  {
    file << s.name << "," << s.progress << endl;
  }
  file.close();
}

// Add a new subject
void addSubject()
{
  vector<Subject> subjects = loadSubjects();
  Subject s;
  cout << "\nEnter subject name: ";
  cin.ignore();
  getline(cin, s.name);

  cout << "Enter progress (0–100): ";
  cin >> s.progress;
  if (s.progress < 0 || s.progress > 100)
  {
    cout << "⚠ Invalid progress! Must be between 0–100.\n";
    return;
  }

  subjects.push_back(s);
  saveSubjects(subjects);
  cout << "✅ Subject added successfully!\n";
}

// Update subject progress
void updateProgress()
{
  vector<Subject> subjects = loadSubjects();
  if (subjects.empty())
  {
    cout << "\n⚠ No subjects found! Add one first.\n";
    return;
  }

  cout << "\nAvailable Subjects:\n";
  for (size_t i = 0; i < subjects.size(); ++i)
  {
    cout << i + 1 << ". " << subjects[i].name << " (" << subjects[i].progress << "%)\n";
  }

  cout << "\nEnter subject number to update: ";
  int choice;
  cin >> choice;

  if (choice < 1 || choice > subjects.size())
  {
    cout << "❌ Invalid subject number.\n";
    return;
  }

  cout << "Enter new progress (0–100): ";
  int newProgress;
  cin >> newProgress;

  if (newProgress < 0 || newProgress > 100)
  {
    cout << "⚠ Invalid progress! Must be between 0–100.\n";
    return;
  }

  subjects[choice - 1].progress = newProgress;
  saveSubjects(subjects);
  cout << "✅ Progress updated successfully!\n";
}

// Show all subjects and progress
void showProgress()
{
  vector<Subject> subjects = loadSubjects();
  if (subjects.empty())
  {
    cout << "\n⚠ No subjects to show!\n";
    return;
  }

  cout << "\n📊 Study Progress Tracker\n";
  cout << left << setw(25) << "Subject" << "Progress (%)" << endl;
  cout << "----------------------------------------\n";
  for (auto &s : subjects)
  {
    cout << left << setw(25) << s.name << s.progress << "%" << endl;
  }
}

// Main program menu
int main()
{
  int choice;

  do
  {
    cout << "\n===== 📘 SMART STUDY PLANNER =====\n";
    cout << "1. Add Subject\n";
    cout << "2. Update Progress\n";
    cout << "3. Show Progress\n";
    cout << "4. Exit\n";
    cout << "Enter your choice: ";

    cin >> choice;

    if (cin.fail())
    {
      cin.clear();
      cin.ignore(1000, '\n');
      cout << "⚠ Invalid input! Please enter a number (1–4).\n";
      continue;
    }

    switch (choice)
    {
    case 1:
      addSubject();
      break;
    case 2:
      updateProgress();
      break;
    case 3:
      showProgress();
      break;
    case 4:
      cout << "👋 Exiting Smart Study Planner...\n";
      break;
    default:
      cout << "❌ Invalid choice! Try again.\n";
    }

  } while (choice != 4);

  return 0;
}