/* Header file for history array  *
 * by Bryce Schroeder.            */
#ifndef _HISTORY_ARRAY_H_
#define _HISTORY_ARRAY_H_
#include <stdlib.h>
#define HISTORY_WIDTH 120
#include <assert.h>
#include <string.h>
#include <stdio.h>
/* Example of the circular array after filling with eight elements a-h
 *   0: a       Suppose we add a new element j.
 *   1: b       We want to replace the oldest element 
 *   2: c       This is a. But since it is the second from last we want to
 *   3: d       list it as the second, not the last. So we move 'tail' from
 *   4: e       0 to 1. Now the logical order is still b-j but the physical
 *   5: f       order is j,b-h.
 *   6: g
 *   7: h
 */

/* This structure describes a history array instance.                       *
 *                                                                          *
 * current: the number of insertions.                                       *
 * size: the maxiumum size of the cirular array                             */
typedef struct {
    //size_t tail;
    size_t size;
    size_t current;
    char **content;
} history_array_t;

/* Create a new history array (allocates new memory)                        *
 * size: how many items will the circular array hold?                       */
history_array_t *history_new   (size_t size);

/* Dispose of a history array. (frees memory allocated by the constructor)  *
 * history: the array to be deallocated.                                    */
void             history_free  (history_array_t *history);

/* Add a new item to the history array. A local copy will be made.          *
 * history: the array to add the item to.                                   *
 * item:    the string which is to be copied into the array.                */
void             history_append(history_array_t *history, 
                                const char      *item);

/* Get an item from the history. The pointer is read-only.                  *
 * history: the array to get the item from.                                 *
 * index: the logical index of the item (in the order inserted, from 0.)    */
const char      *history_get   (history_array_t *history,
                                size_t           index);

/* Get the size of a history array.                                         *
 * history: the array to get the size of.                                   */
size_t           history_size  (history_array_t *history);

/* Get the current number of items of a history array.                      *
 * history: the array to get the size of.                                   */
size_t           history_len   (history_array_t *history);

/* Check to see if the string is present in a history array.                *
 * history: the history array to be checked                                 *
 * item: the string to be searched for.                                     */
int              history_check (history_array_t *history, 
                                const char      *item);

/* Show the items in a history array by logical index.                      *
 * history: the array to show.                                              */
void             history_show  (history_array_t *history);

#endif /* _HISTORY_ARRAY_H_ */