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

struct car* add_car(struct car* first,const char* target) {
    	struct car* new = calloc(1, sizeof(struct car));
	if(!new) return first;  // copirovanie cielvej stanice
	strcpy(new->value,target);
	if (first==NULL){
		return new; // ak nebolo first, new bude prvy
	}
	
	struct car* sm = first; 
	while(sm->next!=NULL){
		sm = sm->next;
	}
	sm->next = new; // pridavanie vozna na koniec
	return first;
	
}

void print_train(struct car* first) {
	struct car* hlp = first; //pomocna struktura
	while(hlp!=NULL){ // ak je vozen
		printf("Cielova stanica je %s\n",hlp->value); // vypis cielovych stanic voznov
		hlp = hlp->next;
	
	}
}


void cancel_train(struct car* first) {
	if(!first) return;
	cancel_train(first->next); // recursivna funkcia, ktora vymaze uplne vlak
	free(first);
}


struct car* clear_train(struct car* first, const char* target) {
	if(!first) return NULL;
	if (strcmp(first->value, target)==0){
		struct car* tmp = first->next;
		free(first);
		return tmp; // vrati to co bolo vymazane ak bol iba jeden vozen
	}
	struct car* hlp = first;
	while (hlp->next!=NULL&&strcmp(hlp->next->value,target)!=0){
		hlp = hlp->next; //hlada vozen
	}
	if (hlp->next!=NULL&&strcmp(hlp->next->value,target)==0){
		struct car* del = hlp->next;
		hlp->next=hlp->next->next; // spoji predchadzajuci a nasledujuci vozen 
		free(del); //vymaze vozen
	}
	return first; // link na zaciatok vlaku
}