ActuallyAdditions/src/main/java/de/ellpeck/actuallyadditions/common/inventory/slot/SlotItemHandlerUnconditioned.java

package de.ellpeck.actuallyadditions.common.inventory.slot;

import javax.annotation.Nonnull;

import de.ellpeck.actuallyadditions.common.util.ItemStackHandlerAA;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.item.ItemStack;
import net.minecraftforge.items.SlotItemHandler;

public class SlotItemHandlerUnconditioned extends SlotItemHandler {

    private final ItemStackHandlerAA inv;

    public SlotItemHandlerUnconditioned(ItemStackHandlerAA inv, int index, int xPosition, int yPosition) {
        super(inv, index, xPosition, yPosition);
        this.inv = inv;
    }

    @Override
    public boolean isItemValid(ItemStack stack) {
        if (stack.isEmpty() || !this.inv.canAccept(this.getSlotIndex(), stack, false)) return false;

        ItemStack currentStack = this.inv.getStackInSlot(this.getSlotIndex());
        this.inv.setStackInSlot(this.getSlotIndex(), ItemStack.EMPTY);
        ItemStack remainder = this.inv.insertItem(this.getSlotIndex(), stack, true, false);
        this.inv.setStackInSlot(this.getSlotIndex(), currentStack);
        return remainder.isEmpty() || remainder.getCount() < stack.getCount();
    }

    /**
     * Helper fnct to get the stack in the slot.
     */
    @Override
    @Nonnull
    public ItemStack getStack() {
        return this.inv.getStackInSlot(this.getSlotIndex());
    }

    @Override
    public void putStack(ItemStack stack) {
        this.inv.setStackInSlot(this.getSlotIndex(), stack);
        this.onSlotChanged();
    }

    @Override
    public int getItemStackLimit(ItemStack stack) {
        ItemStack maxAdd = stack.copy();
        maxAdd.setCount(stack.getMaxStackSize());
        ItemStack currentStack = this.inv.getStackInSlot(this.getSlotIndex());
        this.inv.setStackInSlot(this.getSlotIndex(), ItemStack.EMPTY);
        ItemStack remainder = this.inv.insertItem(this.getSlotIndex(), maxAdd, true, false);
        this.inv.setStackInSlot(this.getSlotIndex(), currentStack);
        return stack.getMaxStackSize() - remainder.getCount();
    }

    @Override
    public boolean canTakeStack(EntityPlayer playerIn) {
        return !this.inv.extractItem(this.getSlotIndex(), 1, true, false).isEmpty();
    }

    @Override
    public ItemStack decrStackSize(int amount) {
        return this.inv.extractItem(this.getSlotIndex(), amount, false, false);
    }
}