// "DoublyLinkedList.cpp"
#include<iostream>
#include<conio.h>
using namespace std;
class node
{ 
public:
 int data;
 node *right_link, *left_link;
};
class friend_node
{
private:
 
 node *head, *current_node;
 void add_to_list(int);
 int move_right();
 int move_left();
 void display_list();
 void delete_record();
 void dispose_list();
 void print_options();
public:
 
 friend_node();
 ~friend_node();
 void handle_choice();
};
friend_node::friend_node()
{
 head = new node;
 head->data = 0;
 head->left_link = head;
 head->right_link = head;
 current_node = head;
}
friend_node::~friend_node()
{
 delete head;
}
void main()
{
 friend_node go;
 cout << "Welcome to the Doubly Linked List Simulation\n\n";
 cout << "1 - Exit program\n";
 cout << "2 - Add\n";
 cout << "3 - Move left\n";
 cout << "4 - Move right\n";
 cout << "5 - Print\n";
 cout << "6 - Delete\n";
 cout << "7 - Dispose\n";
 cout << "8 - Show these options again\n";
 go.handle_choice();
}
void friend_node::handle_choice()
{
 friend_node free_memory;
 int value;
 int choice;
 while (choice != 1)
 {
  cout << "\nEnter choice: ";
  cin >> choice;
  int temp = 0;
  switch(choice)
  {
   case 1:
   free_memory.~friend_node();
   cout << "\nThank you!\n\n";
   getch();
   exit(1);
   break;	  
 
   case 2:
   cout << "\nEnter a number: ";
   cin >> value;
   temp = value;
   cout << "\n" << temp << " has been added!\n";
   getch();
   add_to_list(value); 
   break;	  
 
   case 3:
   cout << "\nCurrent data to the left is:  " << move_left() << "\n\n";
   getch();
   break;	  
 
   case 4:
   cout << "\nCurrent data to the right is:  " << move_right() << "\n\n";
   getch();
   break;
   case 5:
   display_list();
   break;
 
   case 6:
   delete_record();
   break;
   case 7:
   dispose_list();
   break;
 
   case 8:
   print_options();
   break;
   default:
   cout << "\nInvalid choice!\n\n";
   getch();
   break;
  }
 }
}
void friend_node::add_to_list(int add_data)
{
 node *add = new node;
 add->data = add_data;
 add->left_link = current_node;
 add->right_link = current_node->right_link;
 current_node->right_link->left_link = add;
 current_node->right_link = add;
 current_node = add;
}
int friend_node::move_left()
{
 char empty[30] = {"\n\n\a\a\a\aThe list is empty!\n\n"};
 if(head->right_link == head)
 {
  cout << empty << endl;
  getch();
  handle_choice();
 }
 else
 {
  current_node = current_node->left_link;
 
  if(current_node == head)
  {
   current_node = current_node->left_link;
   return (current_node->data);
  }
  else
   return(current_node->data);
 }
 return (0);
}
int friend_node::move_right()
{
 char empty[30] = {"\n\n\a\a\a\aThe list is empty!\n\n"};
 
 if(head->right_link == head)
 {
  cout << empty << endl;
  getch();
  handle_choice();
 }
 
 else
 {
  current_node = current_node->right_link;
  if(current_node == head)
  {
	current_node = current_node->right_link;
	return (current_node->data);
  }
  else
   return(current_node->data);
 }
 return (0);
}
void friend_node::display_list(void)
{
 char empty[30] = {"\n\n\a\a\a\aNothing to print!\n\n"};
 node *print;
 if(head->right_link == head)
 {
  cout << empty << endl;
  getch();
  handle_choice();
 }
 else
 {
  cout << "\nCurrent data in the list:  ";
  print = head->right_link;
  while(print != head)
  {
   cout << print->data <<" ";
   print = print->right_link;
  }
 }
 getch();
 cout <<"\n\n";
}
void friend_node::delete_record()
{
 char empty[30] = {"\n\n\a\a\a\aNothing to delete!\n\n"};
 node *temp_current = new node;
 node *temp_current2 = temp_current;
 temp_current = current_node;
 if (head->right_link == head)
 {
  cout << empty << endl;
  getch();
  handle_choice();
 }
 while(current_node != head)
 {
  cout << "\n\n" << current_node->data << " has been deleted!\n\n";
  current_node->left_link->right_link = current_node->right_link;
  current_node->right_link->left_link = current_node->left_link;
  current_node = current_node->right_link;
  current_node = current_node->left_link;
  getch();
  handle_choice();
 }
}
void friend_node::dispose_list()
{
 char empty[30] = {"\n\n\a\a\a\aNothing to dispose!\n\n"};
 if(head->right_link == head)
 {
  cout << empty << endl;
  getch();
  handle_choice();
 }
 while(current_node != head)
 {
  current_node->left_link->right_link = current_node->right_link;
  current_node->right_link->left_link = current_node->left_link;
  current_node = current_node->right_link;
  current_node = current_node->left_link;
  if(current_node == head)
  {
   cout << "\n\nThe list has been disposed!\n\n";
   getch();
  }
 }
}
void friend_node::print_options()
{
 cout << "\n\n1 - Exit program\n";
 cout << "2 - Add\n";
 cout << "3 - Move left\n";
 cout << "4 - Move right\n";
 cout << "5 - Print\n";
 cout << "6 - Delete\n";
 cout << "7 - Dispose\n";
 cout << "8 - Show these options again\n\n";
}