#include "linkedlist.h"
#include <iostream>
using namespace std;

template <typename T>
linkedlist<T>::linkedlist()
	: root(NULL)
{

}

template <typename T>
linkedlist<T>::~linkedlist()
{
	node<T>* temp = root;
	while(temp){
		node<T>* todelete = temp;
		temp = temp->next;
		delete todelete;
	}
	root = NULL;
}
/*
template <typename T>
void linkedlist<T>::print()
{
	cout << "no console output for this datatype" << endl;
}

template <>
void linkedlist<int>::print()
{
	node<int>* temp = root;
	while(temp){
		cout << temp->getdata() << " -> ";
		temp = temp->next;
	}
	cout << endl;
}
*/
template <typename T>
void linkedlist<T>::print(node<T>* inputnode)
{
	node<T>* temp = inputnode;
	while(temp){
		cout << temp->getdata() << " -> ";
		temp = temp->next;
	}
	cout << endl;
}

template <typename T>
void linkedlist<T>::insert(const T& data)
{
	cout << data << endl;
	if(!root)
	{
		root = new node<T>(data);
		print(root);
		return;
	}
	node<T>* temp = root;
	print(root);
	while(temp && temp->next != NULL)
	{
		temp = temp->next;
	}
	temp->next = new node<T>(data);
	print(root);
}

template <typename T>
node<T>* incrementby(node<T>* inputnode,int n)
{
	node<T>* temp = inputnode;
	while(temp && --n > -1)
	{
		temp = temp->next;
	}
	return temp;
}

/*
	1 2 3 4 5 6 7
	1 3
	2 4
*/

template <typename T>
void linkedlist<T>::reverse_even_nodes()
{
	print(root);
	node<T>* temp = root;
	node<T>* secondhead = NULL;
	while(temp)
	{
		node<T>* tempnext = temp->next;
		if(tempnext)
		{
			temp->next = tempnext->next;
		}
		temp = tempnext;
		if(!secondhead)
		{
			secondhead = tempnext;
		}
	}
	print(root);
	print(secondhead);
	node<T>* reversed_even_node_head = reverse(secondhead);
	temp = root;
	print(reversed_even_node_head);
	while(temp && reversed_even_node_head)
	{
		node<T>* reversed_temp_node = reversed_even_node_head;
		reversed_even_node_head = reversed_even_node_head->next;
		node<T>* tempnext = temp->next;
		reversed_temp_node->next = tempnext;
		temp->next = reversed_temp_node;
		temp = tempnext;
	}
	print(root);
}

template <typename T>
node<T>* linkedlist<T>::reverse(node<T>* inputnode)
{
	node<T>* firstnode = inputnode;
	node<T>* secondnode = NULL;
	node<T>* currenthead = inputnode;
	while(firstnode)
	{
		secondnode = firstnode->next;
		if(secondnode)
		{
			firstnode->next = secondnode->next;
			secondnode->next = currenthead;
			currenthead = secondnode;
		}
		else
		{
			break;
		}
		secondnode = NULL;
	}
	return currenthead;
}