/*
 * This file is part of Applied Energistics 2.
 * Copyright (c) 2013 - 2014, AlgorithmX2, All rights reserved.
 *
 * Applied Energistics 2 is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Applied Energistics 2 is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with Applied Energistics 2.  If not, see <http://www.gnu.org/licenses/lgpl>.
 */

package appeng.debug;


import java.util.ArrayDeque;
import java.util.Queue;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;

import net.minecraft.item.Items;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.tileentity.TileEntityType;
import net.minecraft.util.Direction;
import net.minecraft.util.NonNullList;
import net.minecraft.util.registry.Registry;
import net.minecraftforge.common.capabilities.Capability;
import net.minecraftforge.common.util.LazyOptional;
import net.minecraftforge.items.CapabilityItemHandler;
import net.minecraftforge.items.IItemHandler;

import appeng.tile.AEBaseTile;
import net.minecraftforge.registries.ForgeRegistries;


public class TileItemGen extends AEBaseTile
{

	private static final Queue<ItemStack> POSSIBLE_ITEMS = new ArrayDeque<>();

	private final IItemHandler handler = new QueuedItemHandler();

	public TileItemGen(TileEntityType<?> tileEntityTypeIn) {
		super(tileEntityTypeIn);
		if( POSSIBLE_ITEMS.isEmpty() )
		{
			for( final Item mi : ForgeRegistries.ITEMS)
			{
				if( mi != null && mi != Items.AIR )
				{
					if( mi.isDamageable() )
					{
						// FIXME: Rethink if this branch is necessary
						for( int dmg = 0; dmg < mi.getMaxDamage(); dmg++ )
						{
							ItemStack item = new ItemStack(mi, 1);
							item.setDamage(dmg);
							POSSIBLE_ITEMS.add(item);
						}
					}
					else
					{
						if (mi.getGroup() == null) {
							continue;
						}

						final NonNullList<ItemStack> list = NonNullList.create();
						mi.fillItemGroup( mi.getGroup(), list );
						POSSIBLE_ITEMS.addAll( list );
					}
				}
			}
		}
	}

	@SuppressWarnings("unchecked")
	@Override
	@Nullable
	public <T> LazyOptional<T> getCapability(Capability<T> capability, @Nullable Direction facing )
	{
		if( CapabilityItemHandler.ITEM_HANDLER_CAPABILITY == capability )
		{
			return (LazyOptional<T>) LazyOptional.of(() ->this.handler);
		}
		return super.getCapability( capability, facing );
	}

	class QueuedItemHandler implements IItemHandler
	{

		@Override
		@Nonnull
		public ItemStack insertItem( int slot, @Nonnull ItemStack stack, boolean simulate )
		{
			return stack;
		}

		@Override
		@Nonnull
		public ItemStack getStackInSlot( int slot )
		{
			return POSSIBLE_ITEMS.peek() != null ? POSSIBLE_ITEMS.peek().copy() : ItemStack.EMPTY;
		}

		@Override
		public boolean isItemValid(int slot, @Nonnull ItemStack stack) {
			return false;
		}

		@Override
		public int getSlots()
		{
			return 1;
		}

		@Override
		public int getSlotLimit( int slot )
		{
			return 1;
		}

		@Override
		@Nonnull
		public ItemStack extractItem( int slot, int amount, boolean simulate )
		{
			final ItemStack is = POSSIBLE_ITEMS.peek();

			if( is == null )
			{
				return ItemStack.EMPTY;
			}

			return simulate ? is.copy() : this.getNextItem();
		}

		private ItemStack getNextItem()
		{
			final ItemStack is = POSSIBLE_ITEMS.poll();

			POSSIBLE_ITEMS.add( is );
			return is.copy();
		}
	};
}