#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) {
    if(first == NULL){
        return NULL;
    }
    if (first->next == NULL && strcmp(first->value, target) == 0)
    {
        free(first);
        return NULL;
    }
    else if(first->next == NULL && strcmp(first->value, target) != 0){
        return first;
    }
    if(first->next->next == NULL && strcmp(first->value, target) == 0){
       struct car* temp = first;
       first = first->next;
       first->next = NULL;
       free(temp);
       return first;

    }
    struct car* temp = first;
    struct car* next = first->next;
    while (next->next)
    {if(strcmp(next->value, target) == 0){
        next->next = NULL;
        temp->next = next->next;
        free(next);

    }
    else{
    temp = next;
    next = next->next;}
    
    }
    
	return first;
}