#include "stack.h"
#include <stdexcept>

Stack::Stack(Stack const& other)
    : first{clone(other.first)}
{
}

Stack& Stack::operator=(Stack const& other)
{
    Stack tmp {other};
    std::swap(tmp.first, first);
    return *this;
}

Stack::Stack(Stack && other)
    : first{other.first}
{
    other.first = nullptr;
}

Stack& Stack::operator=(Stack && other)
{
    std::swap(other.first, first);
    return *this;
}


Stack::~Stack()
{
    while(not is_empty())
    {
        pop();
    }
}

void Stack::push(int v)
{
    first = new Node{v, first};
}

int Stack::top() const
{
    if (is_empty())
    {
        throw std::out_of_range("Stack is empty");
    }

    return first->value;
}

void Stack::pop()
{
    if (is_empty())
    {
        throw std::out_of_range("Stack is empty");
    }
    
    Node* to_remove {first};
    first = first->next;
    delete to_remove;
}

bool Stack::is_empty() const
{
    return first == nullptr;
}

Stack::Node* Stack::clone(Stack::Node* n)
{
    if (n == nullptr)
    {
        return nullptr;
    }
    return new Node{n->value, clone(n->next)};
}