// file: example_00.cc
//

// local include files
//
#include "Example.h"

//------------------
//
// implementations for class Node
//
//------------------

// method: default constructor
//
Node::Node() {

  // initialize variables
  //
  data_d = (char*)NULL;
  next_d = (Node*)NULL;

  // exit gracefully
  //
}

// method: destructor
//
Node::~Node() {

  // do some bookkeeping
  //
  Node* tmp = next_d;

  // exit gracefully
  //
}

// method: set_data
//
void Node::set_data(char* data_a) {

  // allocate space
  //
  data_d = new char[strlen(data_a) + 1];
  strcpy(data_d, data_a);

  // exit gracefully
  //
}

// method: set_next
//
void Node::set_next(Node* next_a) {

  // link the pointers
  //
  next_d = next_a;

  // exit gracefully
  //
}

// method: get_data
//
// Note that this method is dangerous because it is returning
// a pointer to data internal to a class.
//
char* Node::get_data() {
  return (char*)data_d;
}

// method: get_next
//
// Note that this method is dangerous because it is returning
// a pointer to data internal to a class.
//
Node* Node::get_next() {
  return next_d;
}

//------------------
//
// implementations for class List
//
//------------------

// method: default constructor
//
List::List() {

  // initialize variables
  //
  head_d = (Node*)NULL;

  // exit gracefully
  //
}

// method: destructor
//
List::~List() {

  // do some bookkeeping
  //
  Node* tmp = head_d;

  // exit gracefully
  //
}

// method: append
//
void List::append(char* data_a) {

  // Create a new node
  //
  Node* new_node_ptr = new Node();
  new_node_ptr->set_data(data_a);
  new_node_ptr->set_next((Node*)NULL);

  // Create a temp pointer
  //
  Node *tmp = head_d;

  // if the list is not null, go to the end of the list
  //
  if (tmp != NULL) {

    // recurse to the end of the list
    //
    while (tmp->get_next() != (Node*)NULL) {
      tmp = tmp->get_next();
    }

    // point the last node to the new node
    //
    tmp->set_next(new_node_ptr);
  }

  // else, if the list is null, create the first node
  //
  else {

    // make the head of the list the new node
    //
    head_d = new_node_ptr;
  }

  // exit gracefully
  //
}

// method: debug
//
void List::debug(FILE* fp_a) {

  // print an informational message
  //
  fprintf(fp_a, "... debugging list ...\n");

  // set up a temporary pointer that we can use
  // to recurse over the list
  //
  Node *tmp = head_d;

  // if the list is empty, return
  //
  if (tmp == (Node*)NULL) {
    fprintf(fp_a, "warning: the list is empty\n");
    return;
  }

  // else: loop over the list
  //
  while (tmp != (Node*)NULL) {

    // display the node
    //
    fprintf(fp_a, "location = %lu\n", (void*)tmp);
    fprintf(fp_a, " the string is stored at = %lu\n", (void*)tmp->get_data());
    fprintf(fp_a, " the value of the string = [%s]\n", tmp->get_data());

    // advance the list
    //
    tmp = tmp->get_next();
  }

  // exit gracefully
  //
  fprintf(fp_a, "... end of debugging list ...\n");
}

// method: get_head
//
Node* List::get_head() {
  return (Node*)head_d;
}