#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_car = (struct car*)malloc(sizeof(struct car));
    if (new_car == NULL) {
        printf("Chyba: Nepodarilo sa alokovať pamäť pre nový vozeň.\n");
        return first;
    }
    strncpy(new_car->value, target, SIZE);
    new_car->next = NULL;

    if (first == NULL) {
        return new_car;
    }

    struct car* temp = first;
    while (temp->next != NULL) {
        temp = temp->next;
    }
    temp->next = new_car;

    return first;
}

void print_train(struct car* first) {
    if (first == NULL) {
        printf("Vlak je prazdny.\n");
        return;
    }
    
    struct car* temp = first;
    while (temp != NULL) {
        printf("Cielova stanica: %s\n", temp->value);
        temp = temp->next;
    }
}

void cancel_train(struct car* first) {
    struct car* temp;
    while (first != NULL) {
        temp = first;
        first = first->next;
        free(temp);
    }
    printf("Vsetky vozne boli zrusene.\n");
}

struct car* clear_train(struct car* first, const char* target) {
    struct car* current = first;
    struct car* previous = NULL;
    
    while (current != NULL) {
        // Porovnanie hodnoty cielovej stanice
        if (strcmp(current->value, target) == 0) {
            // Ak sa cielova stanica zhoduje, odstráni vozeň
            if (previous == NULL) {
                // Ak je to prvý vozeň
                first = current->next;
            } else {
                previous->next = current->next;
            }
            struct car* temp = current;
            current = current->next;
            free(temp);
        } else {
            // Ak sa nezhoduje, prejde na nasledujúci vozeň
            previous = current;
            current = current->next;
        }
    }
    
    return first;
}