#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

typedef struct person {
  char name[50];
  int age;
} person;

typedef struct Node {
  void *content;
  struct Node *next;

} Node;

Node *newNode(void *content) {
  Node *ret = (Node *)malloc(sizeof(Node));
  if (ret == NULL)
    return NULL;
  ret->content = content;
  ret->next = NULL;
  return ret;
}
void appendNode(Node *head, Node *newTail) {

  Node *tail = head;
  while (tail->next != NULL) {
    tail = tail->next;
  }
  tail->next = newTail;
}
void delTail(Node *head) {
  printf("deleting tail\n");
  Node *tail = head;
  while (tail->next->next != NULL) {
    tail = tail->next;
  }
  free(tail->next);
  tail->next = NULL;
}

void printList(Node *head) {
  int count = 0;
  Node *h = head;
  while (h != NULL) {
    printf("%s : %d yeares old  ->  ", ((person *)h->content)->name,
           ((person *)h->content)->age);
    count += 1;
    h = h->next;
  }
  printf("\n%d nodes long\n", count);
}

int main() {
  person p1 = {"alice", 23};
  person p2 = {"bob", 30};
  person p3 = {"mark", 48};
  person p4 = {"bob2", 60};

  Node *np1 = newNode(&p1);
  Node *np2 = newNode(&p2);
  Node *np3 = newNode(&p3);
  Node *np4 = newNode(&p4);

  Node *head = np1;
  appendNode(head, np2);
  appendNode(head, np3);
  appendNode(head, np4);

  printList(head);
  delTail(head);
  printList(head);

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

  return 0;
}