#include "stdstuff.h"
#include "Inventory.h"

// creates a new item in the inventory called "item" with 0 items on hand.
Inventory::Inventory(String2002 item) {
   Inventory::item = item;
   stock = 0;
   minOnHand = 0;
   numSold = 0; 
}

// creates a new item in the inventory called "item" with number items on hand.
// Throws invalid_argument if number is less than zero.
Inventory::Inventory(String2002 item, int number) {
   if ( number < 0 ) { 
       Inventory::item = item; // set up like in default constructor
       stock = 0;
       minOnHand = 0;
       numSold = 0; 
       throw invalid_argument(
              "Inventory::Inventory -- number cannot be negative");
   }
   Inventory::item = item;
   stock = number;
   minOnHand = number;
   numSold = 0;
}

// reduces the inventory by the amount sold.  
// If the amount is negative or will cause the number of items on hand to become
// negative, an invalid_argument is thrown.
void Inventory::sell(int amount) {
   if ( ( amount < 0 ) || ( stock-amount < 0 ) ) throw invalid_argument(
      "Inventory::sell -- amount cannot be negative or cause number on hand to be negative");
   stock -= amount;
   numSold += amount;
   if ( stock < minOnHand ) minOnHand = stock;
}

// stocks up on the item, if required.
// If the number of items on hand is less than the amount given, 20 more items are
// added to the inventory.
// If the amount is negative an invalid_argument is thrown.
void Inventory::stockUp(int amount) {
   if ( amount < 0 ) throw invalid_argument(
      "Inventory::stockUp -- amount cannot be negative");
   if ( stock < amount ) stock += 20;
}

// returns the number of items in the warehouse.
int Inventory::getStock() const {
   return stock;
}

// returns the name of the item.
String2002 Inventory::getItem() const {
   return item;
}

// returns the total number of this item sold to date.
int Inventory::totalSold() const {
   return numSold;
}

// prints the minimum number of this item in the warehouse to date.
void Inventory::printMinInventory() const {
	cout << minOnHand;
}