#include <stdio.h>
#include <stdlib.h>
#include <string.h>

struct Car			// struktura elementu
{
	char number[32];
	char model[64];
};

typedef struct Car Car;

struct ListElement		//struktura elementu listy (dodanie wskaznika na nastepny element)
{
	Car car;
	struct ListElement* next;
};

typedef struct ListElement ListElement;

struct List		// struktura listy (wskaznik na element)
{
	ListElement* head;
};

typedef struct List List;

void pushFront(List* list, const char* number, const char* model)	// dodawanie na poczatek listy
{
	ListElement* element = (ListElement*)malloc(sizeof(ListElement));

	strcpy(element->car.number, number);
	strcpy(element->car.model, model);

	element->next = list->head;
	list->head = element;
}

void pushBack(List* list, const char* number, const char* model)		// dodawanie na koniec listy
{
	ListElement* current = list->head;
	ListElement* element = (ListElement*)malloc(sizeof(ListElement));
	element->next = NULL;

	strcpy(element->car.number, number);
	strcpy(element->car.model, model);

	if (list->head != 0)		// moze byc (current != 0)
	{
		while (current->next != 0)
		{
			current = current->next;
		}
		current->next = element;
	}
	else
		list->head = element;
}

void listOfElements(List* list)		// wylistowanie elementow
{
	ListElement* current = list->head;

	while (current != 0)
	{
		printf("%s %sn", current->car.number, current->car.model);
		current = current->next;
	}
}

void popFront(List* list)		// usuwanie z poczatku listy
{
	ListElement* current = list->head;

	if (current != 0)
	{
		list->head = current->next;
		free(current);
	}
}

void popBack(List* list)		// usuwanie z konca listy
{
	ListElement* current = list->head;
	if (current != 0)
	{
		if (current->next != 0)
		{
			while (current->next->next != 0)
			{
				current = current->next;
			}
			free(current->next);
			current->next = NULL;
		}
		else
		{
			free(list->head);
			list->head = NULL;
		}
	}
}

int getNumberOfElements(List* list)		// zwracanie liczby elementow
{
	int number = 0;
	ListElement* current = list->head;

	while (current != 0)
	{
		number++;
		current = current->next;
	}
	
	return number;
}

ListElement* getAtIndex(List* list, int index) // zwracanie indexu(adresu do elementu)
{
	int i = 0;
	ListElement* current = list->head;

	while (current != 0)
	{
		if (i++ == index)
		{
			return current;
		}
		current = current->next;
	}

	return 0;
}

void insert(List* list, int index, const char* number, const char* model) // wstawianie przed wybranym elementem
{
	ListElement* current = list->head;

	ListElement* neighbor = getAtIndex(list, index); // pobranie elementu przed ktorym ma byc wstawiony nowy
	if (current == neighbor)
	{
		pushFront(list, number, model);
	}
	else
	{
		while (current->next != neighbor)
		{
			current = current->next;
		}

		current->next = (ListElement*)malloc(sizeof ListElement);
		strcpy(current->next->car.number, number);
		strcpy(current->next->car.model, model);
		current->next->next = neighbor;

	}
}

void remove(List* list, int index)  // usuwanie wybranego elementu
{
	ListElement* current = list->head;
	ListElement* neighbor = getAtIndex(list, index);

	if (current == neighbor)
	{
		popFront(list);
	}
	else
	{
		while (current->next != neighbor)
		{
			current = current->next;
		}

		current->next = neighbor->next;
		free(neighbor);
	}
}

void clear(List* list)		// czyszczenie listy
{
	ListElement* current = list->head;

	while (current != 0)
	{
		printf("Usuwam %s %sn", current->car.number, current->car.model);
		ListElement* p = current->next;
		free(current);
		current = p;
	}
}

int main(int argc, char** argv)
{
	List list = { 0 };		// zerowanie head'a (wskaznika listy)
	int number;				// zmienna dla liczby elementow

	pushFront(&list, "ABC 111", "Ford 1000");
	pushFront(&list, "ABC 222", "Ford 1001");
	pushFront(&list, "ABC 333", "Ford 1002");
	pushFront(&list, "ABC 444", "Ford 1003");
	pushFront(&list, "ABC 555", "Ford 1004");
	pushFront(&list, "ABC 666", "Ford 1005");
	pushFront(&list, "ABC 777", "Ford 1006");
	pushFront(&list, "ABC ABC", "Ford 1007");

	listOfElements(&list);

	number = getNumberOfElements(&list);
	printf("nLiczba elementow listy: %dnn", number);

	pushBack(&list, "ABC DEF", "Ford 1008");

	listOfElements(&list);

	number = getNumberOfElements(&list);
	printf("nLiczba elementow listy: %dnn", number);

	insert(&list, 5, "DDD DDD", "Ford 1008");
	insert(&list, 0, "EEE EEE", "Ford 1009");

	//popBack(&list);

	listOfElements(&list);

	number = getNumberOfElements(&list);
	printf("nLiczba elementow listy: %dnn", number);

	//popFront(&list);

	remove(&list, 5);
	remove(&list, 0);

	listOfElements(&list);

	number = getNumberOfElements(&list);
	printf("nLiczba elementow listy: %dnn", number);

	clear(&list);

	return 0;
}