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

struct car* add_car(struct car* first,const char* target) {
    if(first == NULL){
        first = calloc(1, sizeof(struct car));
        strcpy(first->value, target);
        return first;
    }

    struct car* temp = first;
    while(temp->next){
        temp = temp->next;
    }
    struct car* newCar = (struct car*)calloc(1, sizeof(struct car));
    strcpy(newCar->value, target);
    temp->next = newCar;
    return first;

}

void print_train(struct car* first) {
     struct car* temp = first;
     while(temp){
        printf("%s\n", temp->value);
        temp = temp->next;

     }

    
}

void cancel_train(struct car* first) {
    if(first == NULL){
        return;
    }
    cancel_train(first->next);
    free(first);
}


struct car* clear_train(struct car* first, const char* target) {
  struct car* curr = first;
    struct car* prev = NULL;

    while (curr) {
        if (strcmp(curr->value, target) == 0) {
            struct car* to_delete = curr;
            if (prev)
                prev->next = curr->next;
            else
                first = curr->next;
            curr = curr->next;
            free(to_delete);
        } else {
            prev = curr;
            curr = curr->next;
        }
    }

    return first;
}