#include "Q_Node.h"

Q_Node::Q_Node() : element(nullptr), next(nullptr) {};

Q_Node::~Q_Node()
{
    next = nullptr;
}

void Q_Node::set_element(Node* element)
{
    this->element = element;
}

Node* Q_Node::get_element()
{
    return element;
}

void Q_Node::set_next(Q_Node* pointer)
{
    next = pointer;
}

Q_Node* Q_Node::get_next()
{
    return next;
}

#include "Q_Node.h"
#include <stdexcept>
using namespace std;

class Queue
{
private:
    int size;
    Q_Node* first , * last;
public:
    Queue();

    ~Queue();

    // Adds an element in the end of the queue
    void enqueue(Node*);
    // Extracts the first element of the queue and returns its data
    Node* dequeue();
    //Returns data information of the first element
    Node* peek();
    //Returns the size of the queue
    int get_size();
};

Queue::Queue() : size(0), first(NULL), last(NULL) {};

Queue::~Queue()
{
    while (first)
    {
        last = first;
        first = first->get_next();
        delete last;
    }
}

void Queue::enqueue(Node* element)
{
    size++;
    Q_Node* temp = new Q_Node;
    temp->set_element(element);
    if (first == NULL)
    {
        first = last = temp;
    }
    else
    {
        last->set_next(temp);
        last = temp;
    }
}

Node* Queue::dequeue()
{
    if (first == NULL)
        throw out_of_range("The queue is empty");
    size--;
    Q_Node* temp = first;
    first = first->get_next();
    Node* element = temp->get_element();
    delete temp;
    return element;
}

Node* Queue::peek()
{
    if (first == NULL)
        throw out_of_range("The queue is empty");
    return first->get_element();
}

int Queue::get_size()
{
    return size;
}