//
// Created by Mi on 24.11.2019.
//

#ifndef LINKEDLIST_LINKEDLIST_H
#define LINKEDLIST_LINKEDLIST_H

#include <stdlib.h>

typedef struct Node node;
typedef struct LinkedList List;

typedef node* iterator;

struct Node
{
	node* next;
	node* prev;

	int _data;
};

struct LinkedList
{
	node* head;
	node* tail;

	iterator iter;
	int length;
};

List* CreateList(int t_data)
{
	List *list = malloc(sizeof(List));
	list->head = malloc(sizeof(node));
	list->tail = list->iter = list->head;

	list->iter->_data = t_data;
	list->iter->next = list->iter->prev = NULL;

	list->length = 1;
	return list;
}

node* CreateNode(int t_data)
{
	iterator new_node = malloc(sizeof(node));
	new_node->prev = new_node->next = NULL;
	new_node->_data = t_data;

	return new_node;
}

iterator begin(List *list)
{
	return list->head;
}

iterator end(List *list)
{
	return list->tail;
}

iterator get_iterator(List *list, int t_index)
{
	list->iter = list->head;
	for(int i = 0; i < t_index; ++i, list->iter = list->iter->next)
		;
	return list->iter;
}

void push_back(List *list, int t_data)
{
	if (!list)
	{
		puts("List nullptr");
		return;
	}
	if (!list->head->next)
	{
		list->tail = CreateNode(t_data);
		list->length++;

		list->head->next = list->tail;
		list->tail->prev = list->head;
		return;
	}
	list->iter = end(list);
	list->tail = CreateNode(t_data);
	list->iter->next = end(list);
	list->tail->prev = list->iter;

	list->length++;
}

void push_front(List *list, int t_data)
{
	if (!list)
	{
		puts("List nullptr");
		return;
	}
	node* new_node = CreateNode(t_data);
	new_node->prev = NULL;
	new_node->next = begin(list);
	list->head->prev = new_node;
	list->head = new_node;

	list->length++;
}

void insert(List *list, int t_data, int t_index)
{
	if (!list)
	{
		puts("List nullptr");
		return;
	}
	if (t_index > list->length || t_index < 0)
	{
		puts("Out of range!");
		return;
	}

	if (!t_index)
	{
		push_front(list, t_data);
		return;
	}
	if (t_index == list->length)
	{
		push_back(list, t_data);
		return;
	}

	list->iter = begin(list);
	for (int i = 0; i < t_index - 1; ++i, list->iter = list->iter->next)
		;
	node* new_node = CreateNode(t_data);
	new_node->next = list->iter->next;
	new_node->prev = list->iter;
	list->iter->next = new_node;

	list->length++;
}

#endif //LINKEDLIST_LINKEDLIST_H