module linkedlist;
import std::io;

struct Vector2 {
  int x;
  int y;
}

struct Node {
  // Node.x
  //struct {
  //  int x;
  //}
  Vector2 *vec;
  Node *next;
}

fn Node* init(Vector2 *vec) {

  Node *node = alloc::alloc(mem, Node);
  node.vec = vec;
  node.next = null;
  return node;
}


// &self == Node *self
fn void Node.append(&self, Vector2 *v2) {

  Node *newNode = init(v2);

  Node *prev;
  Node *current = self;
  while (current != null) {
    prev = current;
    current = current.next;
  }

  prev.next = newNode;
  newNode.next = null;

}

fn void Node.insertAfter(&self, Vector2 *key, Vector2 *v2) {
  Node *newNode = init(v2);
  newNode.vec = v2;

  Node *current = self;

  while (current != null) {
    if (current.vec == key) {
      break;
    }

    current = current.next;
  }

  newNode.next = current.next;
  current.next = newNode;
}


fn void Node.deleteNode(&self, Vector2 *key) {
  Node *current = self;
  Node *prev;

  while (current != null) {
    if (current.vec == key) {
      break;
    }
    prev = current;
    current = current.next;

  }

  prev.next = current.next;
  alloc::free(mem, current);
}


fn void Node.printList(&self) {
  Node *current = self;

  io::printf("head-> ");
  while (current != null) {
    io::printf("(%d, %d) -> ", current.vec.x, current.vec.y);
    current = current.next;
  }

  io::printfn("tail");
}

fn uint Node.count(&self) {

  uint count = 0;
  Node *current = self;

  while (current != null) {
    count++;
    current = current.next;
  }
  return count;
}

fn int main(String[] args) {
  Vector2 v1 = { .x = 1, .y = 2 };
  Vector2 v2 = { .x = 3, .y = 4 };
  Vector2 v3 = { .x = 5, .y = 6 };
  Vector2 v4 = { .x = 7, .y = 8 };
  Node* list = init(&v1);
  list.append(&v2);
  list.append(&v3);
  list.printList();
  io::printfn("count: %d", list.count());
  list.insertAfter(&v2, &v4);
  list.printList();
  io::printfn("count: %d", list.count());

  list.deleteNode(&v4);
  list.printList();
  io::printfn("count: %d", list.count());

	return 0;
}