/*
 * YOU NEED TO DOCUMENT THIS INTERFACE FILE, INCLUDING THE CONSTANTS,
 * TYPES AND FUNCTION PROTOTYPES.  FOR THE PROTOTYPES, YOU SHOULD
 * DOCUMENT HOW THEY SHOULD BE USED BY A MAIN PROGRAM.
 *
 * DON'T FORGET TO "WRAP" THIS HEADER FILE (SEE LAB 4).
 */

#define INVENT_NO_ROOM        -1
#define INVENT_NO_SUCH_ITEM   -2
#define INVENT_PRICE_MISMATCH -3
#define INVENT_NOT_ENOUGH     -4
#define INVENT_FILE_ERROR     -5

#define MAX_INVENTORY  200

#define NAME_MAX  20

typedef struct {
  char name[NAME_MAX+1];  /* One extra for the '\0' character. */
  int count;              /* Number of units in stock. */
  int price;              /* Cost of a single unit in cents. */
} itemT;

typedef struct {
  itemT items[MAX_INVENTORY];  /* Stores all the items. */
  int howmany;                 /* How many items currently in inventory. */
} inventoryT;

/*
 * SOME FUNCTIONS BELOW MUST RECEIVE INVENTORY BY REFERENCE SINCE
 * THEY CHANGE INVENTORY.  FOR CONSISTENCY, ALL FUNCTIONS TAKE
 * INVENTORY BY REFERENCE (WHETHER THEY CHANGE INVENTORY OR NOT)...
 * BESIDES, IT'S MORE EFFICIENT THAT WAY.
 */

/*
 * Function: InventoryInitialize
 * Usage: InventoryInitialize(&list);
 * --------------------------
 * HERE WE DESCRIBE HOW TO USE THIS FUNCTION.  ALSO, WE SHOULD
 * DESCRIBE WHAT IT DOES FROM A "HIGH LEVEL", I.E., DON'T DESCRIBE
 * THE INNER DETAILS OF WHAT IT DOES HERE, THOSE COMMENTS GO IN THE
 * IMPLEMENTATION FILE.
 *
 * This procedure initializes an inventory variable so that it
 * represents an empty inventory.
 */
void InventoryInitialize(inventoryT *listP);

int InventoryAddItems(inventoryT *listP, itemT item);

int InventoryRemoveItems(inventoryT *listP, itemT item);

int InventoryGetPrice(inventoryT *listP, itemT item);

int InventorySetPrice(inventoryT *listP, itemT item);

int InventoryReadFromFile(inventoryT *listP, char filename[]);