//
// Created by Julio Tentor <jtentor@fi.unju.edu.ar>
//

#ifndef DEMOQUEUE1_QUEUE_H
#define DEMOQUEUE1_QUEUE_H

#include <stdexcept>

template <class ELEMENT>
class queue {
public:
    queue(int capacity = 10);
    virtual ~queue();
    void push(const ELEMENT & element);
    ELEMENT front();
    void pop();
    const int size();

private:
    int capacity;
    ELEMENT * data;
    int head;
    int tail;
    int count;
    int next(int position);
};

template <class ELEMENT>
queue<ELEMENT>::queue(int capacity) {
    this->capacity = capacity;
    this->data = new ELEMENT[this->capacity];
    this->head = 0;
    this->tail = 0;
    this->count = 0;
}

template <class ELEMENT>
queue<ELEMENT>::~queue() {
    delete [] this->data;
}

template <class ELEMENT>
const int queue<ELEMENT>::size() {
    return this->count;
}

template<class ELEMENT>
int queue<ELEMENT>::next(int position) {
    return (++position >= this->capacity)? 0: position;
}

template<class ELEMENT>
void queue<ELEMENT>::push(const ELEMENT &element) {
    if (this->count >= this->capacity) {
        throw std::runtime_error("ERROR La cola esta llena...");
    }
    this->data[this->tail] = element;
    this->tail = this->next(this->tail);
    ++this->count;
}

template<class ELEMENT>
ELEMENT queue<ELEMENT>::front() {
    if (this->count <= 0) {
        throw std::runtime_error("ERROR La cola esta vacía...");
    }
    return this->data[this->head];
}

template<class ELEMENT>
void queue<ELEMENT>::pop() {
    if (this->count <= 0) {
        throw std::runtime_error("ERROR La cola esta vacía...");
    }
    this->head = this->next(this->head);
    --this->count;
}

#endif //DEMOQUEUE1_QUEUE_H