#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "a_train.h"
struct car* add_car(struct car* first, const char* target){
    if(!strcmp(target, ""))
        return NULL;

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

    struct car* temp = first;

    while(temp->next != NULL)
        temp = temp->next;

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

void print_train(struct car* first){
    struct car* temp = first;

    while(temp != NULL){
        printf("%s\n", temp->value);
        temp = temp->next;
    }
}

void cancel_train(struct car* first){
    if(!first)
        return;

    struct car* temp = first;
    struct car* next = temp->next;

    while(next != NULL){
        next = temp->next;
        free(temp);
        temp = next;
    }

    first = NULL;
}

struct car* clear_train(struct car* first, const char* target){
    if(!first || !strcmp(target, ""))
        return NULL;

    struct car* temp = first;
    struct car* next = temp->next;

    while(temp != NULL){
        next = temp->next;
        if(!strcmp(temp->value, target))
            free(temp);
        temp = next;
        if(!first)
            first = temp;
    }

    return first;
}