#ifndef STACK_H
#define STACK_H

#include "../Exception.h"

template<class T>
class Stack
{
public:
    Stack()
    {
        pos = 0;
        capacity = 4;
        data = new T[capacity];
    }
    
    Stack(const Stack& orig)
    {
        pos = orig.pos;
        capacity = orig.capacity;
        data = new T[capacity];
        memcpy(data, orig.data, capacity * sizeof(T));
    }
    
    Stack& operator=(const Stack& orig)
    {
        delete[] data;
        
        pos = orig.pos;
        capacity = orig.capacity;
        data = new T[capacity];
        memcpy(data, orig.data, capacity * sizeof(T));
        
        return *this;
    }
    
    virtual ~Stack()
    {
        delete[] data;
    }
    
    int getSize()
    {
        return pos;
    }
    
    bool isEmpty()
    {
        return pos == 0;
    }
    
    void push(T t)
    {
        if(pos >= capacity)
        {
            int newCapacity = capacity * 2;
            T* t = new T[newCapacity];
            memcpy(t, data, capacity * sizeof(T));
            delete[] data;
            data = t;
            capacity = newCapacity;
        }
        data[pos] = t;
        pos++;
    }
    
    T pop()
    {
        if(pos == 0)
        {
            throw Exception("pop on empty stack");
        }
        return data[--pos]; 
    }
    
    T peek()
    {
        if(pos == 0)
        {
            throw Exception("peek on empty stack");
        }
        return data[pos - 1];
    }
private:
    int capacity;
    int pos;
    T* data;
};

#endif