#include <iostream>
#include "QueueT.h"

using namespace std;

struct QueueNodeT {
    string data;
    QueueNodeT *  next;
};

QueueT::QueueT(){
     front = nullptr;
     rear = nullptr;
     size = 0;
}

void DeleteQueue(QueueNodeT * front){
    QueueNodeT * tmp;
    
    while (front != nullptr) {
        tmp = front;
        front = front ->next;
        delete tmp;
    }
    return;
}

QueueT::~QueueT(){

    DeleteQueue(front);
    front = nullptr;
    rear = nullptr;
    size = 0;

    return;
}

void CopyList(QueueNodeT * src, QueueNodeT * & dest, QueueNodeT * & rear) {
     QueueNodeT * tmp;

     dest = nullptr;
     rear = nullptr;

     while (src != nullptr) {
         tmp = new QueueNodeT;
         tmp ->next = nullptr;
         tmp->data = src->data; 
         if (dest == nullptr) {
             dest = tmp;
             rear = tmp;
         } else {
             rear ->next = tmp;
             rear = tmp;
         }
         src = src->next;
     }

     return;
}

QueueT::QueueT(const QueueT & src){
    CopyList(src.front, front, rear);
    size = src.size;

    return;
}

QueueT & QueueT::operator = (const QueueT & src){
     if (this != &src){
          DeleteQueue(front);
          CopyList(src.front,front,rear);
          size =src.size;
     }

     return *this;
}

void QueueT::Enqueue(std::string s){
     QueueNodeT * tmp;

     tmp = new QueueNodeT;
     tmp->next = nullptr;
     tmp->data = s;

     if(rear != nullptr) {
         rear->next = tmp;
     } else {
         front = tmp;
     }

     rear = tmp;
     size++;

     return;
}

void QueueT::Dequeue(){
     QueueNodeT * tmp;

     if (front != nullptr) {
        tmp = front;
        front = front->next;
        delete tmp;
        if (front == nullptr) {
            rear = nullptr;
        }
        size--;
     }
     return; 
}

std::string QueueT::Front(){
     string rv = "BAD DATA";
     if (front != nullptr) {
         rv = front->data;
     }

     return rv;
}

bool QueueT::IsEmpty(){
     return front == nullptr;
}

bool QueueT::IsFull(){
     return false;
}

size_t QueueT::Size(){
     return size;
}