public int capShoppingAmount(
int offerId, int wantedAmount, IInventory inv, IFluidHandler fluidHandler) {
AmadronOffer offer = offers.get(offerId);
if (offer.getInput() instanceof ItemStack) {
if (inv != null) {
ItemStack searchingItem = (ItemStack) offer.getInput();
int count = 0;
for (int i = 0; i < inv.getSizeInventory(); i++) {
if (inv.getStackInSlot(i) != null
&& inv.getStackInSlot(i).isItemEqual(searchingItem)
&& ItemStack.areItemStackTagsEqual(inv.getStackInSlot(i), searchingItem)) {
count += inv.getStackInSlot(i).stackSize;
}
}
int maxAmount = count / ((ItemStack) offer.getInput()).stackSize;
if (wantedAmount > maxAmount) {
problemState = EnumProblemState.NOT_ENOUGH_ITEMS;
wantedAmount = maxAmount;
}
} else {
wantedAmount = 0;
problemState = EnumProblemState.NO_ITEM_PROVIDER;
}
} else {
if (fluidHandler != null) {
FluidStack searchingFluid = ((FluidStack) offer.getInput()).copy();
searchingFluid.amount = Integer.MAX_VALUE;
FluidStack extracted = fluidHandler.drain(ForgeDirection.UP, searchingFluid, false);
int maxAmount = 0;
if (extracted != null)
maxAmount = extracted.amount / ((FluidStack) offer.getInput()).amount;
if (wantedAmount > maxAmount) {
problemState = EnumProblemState.NOT_ENOUGH_FLUID;
wantedAmount = maxAmount;
}
} else {
wantedAmount = 0;
problemState = EnumProblemState.NO_FLUID_PROVIDER;
}
}
if (offer.getOutput() instanceof ItemStack) {
if (inv != null) {
ItemStack providingItem = ((ItemStack) offer.getOutput()).copy();
providingItem.stackSize *= wantedAmount;
ItemStack remainder = IOHelper.insert(inv, providingItem.copy(), 0, true);
if (remainder != null) {
int maxAmount =
(providingItem.stackSize - remainder.stackSize)
/ ((ItemStack) offer.getOutput()).stackSize;
if (wantedAmount > maxAmount) {
wantedAmount = maxAmount;
problemState = EnumProblemState.NOT_ENOUGH_ITEM_SPACE;
}
}
} else {
wantedAmount = 0;
problemState = EnumProblemState.NO_ITEM_PROVIDER;
}
} else {
if (fluidHandler != null) {
FluidStack providingFluid = ((FluidStack) offer.getOutput()).copy();
providingFluid.amount *= wantedAmount;
int amountFilled = fluidHandler.fill(ForgeDirection.UP, providingFluid, false);
int maxAmount = amountFilled / ((FluidStack) offer.getOutput()).amount;
if (wantedAmount > maxAmount) {
wantedAmount = maxAmount;
problemState = EnumProblemState.NOT_ENOUGH_FLUID_SPACE;
}
} else {
wantedAmount = 0;
problemState = EnumProblemState.NO_FLUID_PROVIDER;
}
}
return wantedAmount;
}
