#include <iostream>
#include <vector>
#include <fstream>

typedef struct phonebook_entry {
  std::string firstname;
  std::string lastname;
  std::string phone;
} phonebook_entry;

int showMenuSelection() {
  std::cout << std::endl << std::endl;
  std::cout << "-- Phonebook --" << std::endl;
  std::cout << "\t 1 - New Entry" << std::endl;
  std::cout << "\t 2 - Search" << std::endl;
  std::cout << "\t 3 - Clear" << std::endl;
  std::cout << "\t 4 - List" << std::endl;
  std::cout << "\t 9 - Exit" << std::endl;
  std::cout << std::endl << "Selection: ";
  int selection;
  std::cin >> selection;
  return selection;
}

void clear(std::vector<phonebook_entry*> &phonebook) {
  for (phonebook_entry* entry : phonebook) {
    delete entry;
  }
  phonebook.clear();
  phonebook.shrink_to_fit();
}

std::vector<phonebook_entry*> getPhonebookFromFile(std::string filename) {
  std::ifstream file(filename);
  std::vector<phonebook_entry*> phonebook;
  phonebook_entry* entry;

  if (file.is_open()) {
    int rownumber = 0;
    std::string line;
    
    while (file >> line) {
      switch (rownumber % 3) {
        case 0:
          entry = new phonebook_entry;
          entry->firstname = line;
          break;

        case 1:
          entry->lastname = line;
          break;
    
        case 2:
          entry->phone = line;
          phonebook.push_back(entry);
          break;
      }
      rownumber++;
    }

    file.close();
  } else {
    std::cout << "Error opening file!" << std::endl;
  }

  return phonebook;
}

void listPhonebook(std::vector<phonebook_entry*> &phonebook) {
  for (phonebook_entry* entry : phonebook) {
    std::cout << "Firstname: " << entry->firstname << std::endl;
    std::cout << "Lastname: " << entry->lastname << std::endl;
    std::cout << "Phone: " << entry->phone << std::endl; 
    std::cout << std::endl;
  }
}

int main() {
  std::vector<phonebook_entry*> phonebook;
  phonebook = getPhonebookFromFile("phonebook.txt");

  while (int selection = showMenuSelection()) {
    phonebook_entry* entry = new phonebook_entry;

    switch (selection) {
      case 1: {
        std::cout << "-- New Entry (Phonebook) --" << std::endl;
        std::cout << "Firstname: ";
        std::cin >> entry->firstname;
        std::cout << "Lastname: ";
        std::cin >> entry->lastname;
        std::cout << "Phone: ";
        std::cin >> entry->phone;
        phonebook.push_back(entry);
      } break;

      case 2: {
        std::cout << std::endl << std::endl;
        std::cout << "-- Search (Phonebook) --" << std::endl;
        std::cout << "Lastname: ";
        std::string lastname;
        std::cin >> lastname;
  
        bool found = false;
    
        std::cout << std::endl << std::endl;
        std::cout << "-- Search Result --" << std::endl;

        for (phonebook_entry* entry : phonebook) {
          if (entry->lastname == lastname) {
            std::cout << "Lastname: " << entry->firstname << std::endl;
            std::cout << "Firstname: " << entry->lastname << std::endl;
            std::cout << "Phone: " << entry->phone << std::endl;
            found = true;
          }
        }

        if (found == false) {
          std::cout << "No entry found!" << std::endl;
        }
      } break;

      case 3: {
        clear(phonebook);
      } break;

      case 4: {
        std::cout << std::endl << std::endl;
        std::cout << "-- List --" << std::endl;
        listPhonebook(phonebook);
      } break;

      case 9: {
        std::ofstream file("phonebook.txt");
        
        if (file.is_open()) {
          if (phonebook.empty() == false) {
            for (phonebook_entry* entry : phonebook) {
              file << entry->firstname << std::endl;
              file << entry->lastname << std::endl;
              file << entry->phone << std::endl;
            }
          } else {
            file.clear();
          }
          
          file.close();
        }

        clear(phonebook);
        return 0;
      } break;

      default:
        std::cout << std::endl << std::endl;
        std::cout << "Unknown selection. Please try again!";
    }
  }

  return 0;
}