#include "List.h"
#include <iterator>
#include <utility>
#include <stdexcept>

struct List::Node
{
    Node() = default;
    Node(int v, Node* p, Node* n)
        : value{v}, prev{p}, next{n} {}
    int value {};
    Node * prev {};
    Node * next {};
};

List::List()
    : head{ new Node{} }, tail{head}, sz{}
{}

List::List(List const & other)
    : List{}
{
    Node * tmp = other.head;
    while ( tmp != other.tail )
    {
        push_back(tmp->value);
        tmp = tmp->next;
    }
}
List::List(List && tmp) noexcept
    :List{}
{
    swap(tmp);
}
List::List(std::initializer_list<int> lst)
    : List{}
{
    for ( auto val : lst )
    {
        push_back(val);
    }
}

void List::push_front(int value)
{
    head = new Node{value, nullptr, head};
    if ( sz == 0 )
    {
        tail->prev = head;
    }
    ++sz;
}
void List::push_back(int value)
{
    if ( empty() )
    {
        push_front(value);
    }
    else
    {
        tail->prev->next = new Node{value, tail->prev, tail};
        tail->prev = tail->prev->next;
        ++sz;
    }
}

bool List::empty() const
{
    return head == tail;
}

int & List::at(int idx)
{
    if (idx >= sz)
        throw std::out_of_range{"Index not found"};
    Node * tmp {head};
    while ( idx > 0 )
    {
        tmp = tmp->next;
        --idx;
    }
    return tmp->value;
}

int List::size() const
{
    return sz;
}

void List::swap(List & other) noexcept
{
    using std::swap;
    swap(head, other.head);
    swap(tail, other.tail);
    swap(sz, other.sz);
}

List & List::operator=(List const & rhs) &
{
    List{rhs}.swap(*this);
    return *this;
}

List & List::operator=(List && rhs) &
{
    swap(rhs);
    return *this;
}

void List::sort()
{
    bool swapped {true};
    for ( int iteration {}; swapped && iteration < size(); ++iteration )
    {
        swapped = false;
        for ( auto p = head; p != tail; p = p->next )
        {
            if ( p->value > p->next->value )
            {
                swap_nodes(p, p->next);
                swapped = true;
            }
        }
    }
}

}