#include <cstdio>
#include <iostream>
#include <strings.h>

using namespace std;

struct test_struct_def {
  unsigned int ip_address; // An IP address, 32-bits
  char modifier;           // A character, 'b' means block, and 'a' means accept
  unsigned short port;     // A network TCP port
};

/* This is a linked list structure. */
struct test_list {
  struct test_struct_def element;
  struct test_list *next;
};

/* This is a linked list structure. */
struct test_tree {
  struct test_struct_def element;
  struct test_tree *right, *left;
};

/* This is a hash table structure. */
struct test_ht {
  struct test_list *buckets[16];
};

#define MAKE_IP(a,b,c,d) (((a & 0xff) << 24) + ((b & 0xff) << 16) + ((c & 0xff) << 8) + (d & 0xff))

struct test_list*
add_to_list(unsigned int ip, char m, unsigned short p,
            struct test_list *test_list_head) {
  struct test_list *new_obj = new struct test_list;

  new_obj->element.ip_address = ip;
  new_obj->element.port = p;
  new_obj->element.modifier = m;

  if(test_list_head == nullptr) {
    return new_obj;
  }

  struct test_list *ptr = test_list_head;
  for(; ptr->next != nullptr; ptr = ptr->next) {
    // Advance through the list.
  }

  ptr->next = new_obj;

  return test_list_head;
}

int
hash_function(unsigned int val) {
  return (val & 0xf);
}

void
add_to_ht(unsigned int ip, char m, unsigned short p,
          struct test_ht *h) {
  struct test_list *new_obj = new struct test_list;

  new_obj->element.ip_address = ip;
  new_obj->element.port = p;
  new_obj->element.modifier = m;

  int hval = hash_function(ip);

  h->buckets[hval] = add_to_list(ip, m, p, h->buckets[hval]);
}

struct test_tree*
add_to_tree(unsigned int ip, char m, unsigned short p,
            struct test_tree *test_list_tree) {
  struct test_tree *new_obj = new struct test_tree;

  new_obj->element.ip_address = ip;
  new_obj->element.port = p;
  new_obj->element.modifier = m;

  if(test_list_tree == nullptr) {
    return new_obj;
  }

  if(test_list_tree->element.ip_address >= ip) {
    if(test_list_tree->right == nullptr) {
      test_list_tree->right = new_obj;
    } else {
      add_to_tree(ip, m, p, test_list_tree->right);
    }
  } else {
    if(test_list_tree->left == nullptr) {
      test_list_tree->left = new_obj;
    } else {
      add_to_tree(ip, m, p, test_list_tree->left);
    }
  }

  return test_list_tree;
}

int main(int argc, char **argv) {
  struct test_list *l = nullptr;
  struct test_ht ht;
  struct test_tree *tree = nullptr;
  bzero(ht.buckets, sizeof(ht.buckets));

  /* Generate some example data, in linked list. */
  l = add_to_list(MAKE_IP(172,20,22,1), 'a', 3333, l);
  l = add_to_list(MAKE_IP(192,168,4,1), 'b', 444, l);
  l = add_to_list(MAKE_IP(10,2,7,32), 'b', 1777, l);
  l = add_to_list(MAKE_IP(184,138,202,46), 'b', 22, l);
  l = add_to_list(MAKE_IP(127,0,0,1), 'a', 0, l);

  /* Generate some example data, in hash table. */
  add_to_ht(MAKE_IP(172,20,22,1), 'a', 3333, &ht);
  add_to_ht(MAKE_IP(192,168,4,1), 'b', 444, &ht);
  add_to_ht(MAKE_IP(10,2,7,32), 'b', 1777, &ht);
  add_to_ht(MAKE_IP(184,138,202,46), 'b', 22, &ht);
  add_to_ht(MAKE_IP(127,0,0,1), 'a', 0, &ht);

  /* Generate some example data, in tree. */
  tree = add_to_tree(MAKE_IP(172,20,22,1), 'a', 3333, tree);
  tree = add_to_tree(MAKE_IP(192,168,4,1), 'b', 444, tree);
  tree = add_to_tree(MAKE_IP(10,2,7,32), 'b', 1777, tree);
  tree = add_to_tree(MAKE_IP(184,138,202,46), 'b', 22, tree);
  tree = add_to_tree(MAKE_IP(127,0,0,1), 'a', 0, tree);

  cout << "Done" << endl;

  return 0;
};