//
// Author: David Muto
// https://gist.github.com/pseudomuto/6334796#file-list-h
//
//  Modified by:
//         Michael E. Tryby
//         US EPA ORD
//
// Accessed on: April 9, 2019
//


#ifndef LIST_H
#define LIST_H


#include <stdbool.h>

#if defined(__cplusplus)
extern "C" {
#endif

// a common function used to free malloc'd objects
typedef void(*freeFunction)(void *);
typedef bool (*listIterator)(void *);


typedef struct _listNode {
  void *data;
  struct _listNode *next;
} listNode;


typedef struct {
  int logicalLength;
  size_t elementSize;
  listNode *head;
  listNode *tail;
  freeFunction freeFn;
} list_t;


/**
@brief Initializes a linked list to store elements of elementSize and to call
freeFunction for each element when destroying a list.
*/
list_t *create_list(size_t elementSize, freeFunction freeFn);

/**
@brief Frees dynamically allocated nodes and optionally calls freeFunction
with each node’s data pointer.
*/
void delete_list(list_t *list);

/**
@brief Adds a node to the head of the list.
*/
void prepend_list(list_t *list, void *element);

/**
@brief Adds a node to the tail of the list.
*/
void append_list(list_t *list, void *element);

/**
@brief Returns the number of items in the list.
*/
int size_list(list_t *list);

/**
@brief Calls the supplied iterator function with the data element of each
node (iterates over the list).
*/
void for_each_list(list_t *list, listIterator iterator);

/**
@brief Returns the head of the list (optionally removing it at the same time).
*/
void *head_list(list_t *list, bool removeFromList);

/**
@brief Returns the tail of the list.
*/
void *tail_list(list_t *list);


#if defined(__cplusplus)
}
#endif

#endif /* LIST_H */