#include <iostream>
#include <fstream>
#include <queue>
#include <string>
using namespace std;

ifstream fin; // File input stream.
ofstream fout; // File script stream.
ofstream fout2; // File output stream.
string filepath; // Holds file path of input file.

struct Stored_Item // Item stored in linked list
{
		int value;
		Stored_Item* next;
};

class Extended_Queue
{
	public:
		int size;
		Stored_Item* head;
		Stored_Item* tail;

		void Enqueue(int element);
		void Dequeue();
		bool isEmpty();
		int  getSize();
		int  getMid();
		void Make_empty_queue();
		void High_Priority_Queue(int element);
		void Medium_Priority_Queue(int element);
		void printQueueElements();
};

void Extended_Queue::printQueueElements() // Prints the Extended Queue.
{
	Stored_Item* temp;
		temp = head;
		cout << "The Queue is now " << size << " nodes long."  << endl;
		cout << "The Queue's elements are: " << endl;
		fout << "The Queue is now " << size << " nodes long."  << endl;
		fout << "The Queue's elements are: " << endl;
	while(temp != NULL)
		{
			cout << "|" << temp->value << "|";
			fout << "|" << temp->value << "|";
			temp = temp->next;
		}
		cout << endl << endl;
		fout << endl << endl;
}

void Extended_Queue::Enqueue(int element)
{
	if(isEmpty())            // first Stored_Item
	{
		head = new Stored_Item;
		tail = head;       // head becomes the tail
		head->value = element; // value holds element
		head->next = NULL; // head points to nothing
	}
	else
	{
		tail->next = new Stored_Item;
		tail->next->value = element; // Sets value of next link.
		tail->next->next = NULL; // Sets link of next link.
		tail = tail->next; // Sets link of own link.
	}
	cout << element << " has been added to the queue (regular enqueue)." << endl;
	fout << element << " has been added to the queue (regular enqueue)." << endl;
	size++;
	printQueueElements();
}

void Extended_Queue::Dequeue()
{
	if(isEmpty()) // Empty list
	{
		return;
	}
	else if(head == tail) // One item left.
	{
		cout << head->value << " has been dequeued from the queue." << endl;
		fout << head->value << " has been dequeued from the queue." << endl;
		fout2 << head->value << ", ";
		head = NULL;
	}
	else // Remove the first Stored_Item inserted and point to the next.
	{
		Stored_Item *current;
		current = head;
		cout << head->value << " has been dequeued from the queue." << endl;
		fout << head->value << " has been dequeued from the queue." << endl;
		fout2 << head->value << ", ";
		head = current->next;
		current = NULL;
	}
	size--;
	printQueueElements();
}

bool Extended_Queue::isEmpty() // Checks if queue is empty or not
{
	if(getSize() == 0)
	{
		return true;
	}
	else
	{
		return false;
	}
}

int Extended_Queue::getSize() // Returns the number of nodes in the queue.
{
	return size;
}

int Extended_Queue::getMid() // Calculates and returns 1/2 the number of nodes in the queue. 
{
	return (size/2);
}

void Extended_Queue::Make_empty_queue() // Constructor, makes a new empty queue.
{
	size = 0;
	head = NULL;
	tail = NULL;
	cout << "An empty queue has been created." << endl << endl;
	fout << "An empty queue has been created." << endl << endl;
}

void Extended_Queue::High_Priority_Queue(int element) // Adds an element to the front of queue.
{
	Stored_Item* temp;
	temp = new Stored_Item;
	temp->value = element;
	temp->next = head;
	head = temp;
	size++;
	cout << element << " has been added to the front of the queue (high priority)." << endl;
	fout << element << " has been added to the front of the queue (high priority)." << endl;
	printQueueElements();
}

void Extended_Queue::Medium_Priority_Queue(int element) // Adds an element to the middle of queue.
{
	Stored_Item* temp;
	temp = new Stored_Item;
	temp = head;
	for (int i = 1; i < getMid(); i++)
	{
		temp = temp->next;
	}
	Stored_Item* inserted;
	inserted = new Stored_Item;
	inserted->value = element;
	inserted->next = temp->next;
	temp->next = inserted;
	inserted = NULL;
	temp = NULL;
	size++;
	cout << element << " has been added to the middle of the queue (medium priority)." << endl;
	fout << element << " has been added to the middle of the queue (medium priority)." << endl;
	printQueueElements();
}

void main()
{
	Extended_Queue qt;
	cout << "Note: This program will output the items that are dequeued from the list into \n'Homework4Output.txt'  It will also output a script of the program to \n'Homework4Script.txt'" << endl << endl;
	cout << "Please enter input filepath: ";
			cin >> filepath;
			fin.open(filepath.c_str());
			fout.open("Homework4Script.txt");
			fout2.open("Homework4Output.txt");
			fout2 << "The items that are dequeued are: " << endl;
	qt.Make_empty_queue();
	while (!fin.eof())
	{
		char command; // Holds which function will be called.
		int number; // Holds the value to queue.
		fin >> command;

		switch (command)
		{
			case 'e':
				fin >> number;
				qt.Enqueue(number);
				break;
			case 'h':
				fin >> number;
				qt.High_Priority_Queue(number);
				break;
			case 'm':
				fin >> number;
				qt.Medium_Priority_Queue(number);
				break;
			case 'd':
				qt.Dequeue();
				break;
		}
	}
	fin.close();
	cout << "The input is complete.  The queue will now be emptied." << endl << endl;
	fout << "The input is complete.  The queue will now be emptied." << endl << endl;
	while (!qt.isEmpty())
	{
		qt.Dequeue();
	}
}