/*
 * 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.tile;


import java.util.List;

import javax.annotation.Nonnull;

import net.minecraft.item.ItemStack;
import net.minecraft.nbt.CompoundNBT;
import net.minecraft.tileentity.TileEntityType;
import net.minecraft.util.Direction;
import net.minecraft.util.math.BlockPos;
import net.minecraft.world.World;
import net.minecraftforge.common.capabilities.Capability;
import net.minecraftforge.common.util.LazyOptional;
import net.minecraftforge.items.CapabilityItemHandler;
import net.minecraftforge.items.IItemHandler;
import net.minecraftforge.items.wrapper.EmptyHandler;

import appeng.util.helpers.ItemHandlerUtil;
import appeng.util.inv.IAEAppEngInventory;
import appeng.util.inv.InvOperation;


public abstract class AEBaseInvTile extends AEBaseTile implements IAEAppEngInventory
{

	public AEBaseInvTile(TileEntityType<?> tileEntityTypeIn) {
		super(tileEntityTypeIn);
	}

	@Override
	public void read(final CompoundNBT data )
	{
		super.read( data );
		final IItemHandler inv = this.getInternalInventory();
		if( inv != EmptyHandler.INSTANCE )
		{
			final CompoundNBT opt = data.getCompound( "inv" );
			for( int x = 0; x < inv.getSlots(); x++ )
			{
				final CompoundNBT item = opt.getCompound( "item" + x );
				ItemHandlerUtil.setStackInSlot( inv, x, ItemStack.read(item) );
			}
		}
	}

	public abstract @Nonnull IItemHandler getInternalInventory();

	@Override
	public CompoundNBT write(final CompoundNBT data )
	{
		super.write( data );
		final IItemHandler inv = this.getInternalInventory();
		if( inv != EmptyHandler.INSTANCE )
		{
			final CompoundNBT opt = new CompoundNBT();
			for( int x = 0; x < inv.getSlots(); x++ )
			{
				final CompoundNBT item = new CompoundNBT();
				final ItemStack is = inv.getStackInSlot( x );
				if( !is.isEmpty() )
				{
					is.write(item);
				}
				opt.put( "item" + x, item );
			}
			data.put( "inv", opt );
		}
		return data;
	}

	@Override
	public void getDrops( final World w, final BlockPos pos, final List<ItemStack> drops )
	{
		final IItemHandler inv = this.getInternalInventory();

		for( int l = 0; l < inv.getSlots(); l++ )
		{
			final ItemStack is = inv.getStackInSlot( l );
			if( !is.isEmpty() )
			{
				drops.add( is );
			}
		}
	}

	@Override
	public abstract void onChangeInventory( IItemHandler inv, int slot, InvOperation mc, ItemStack removed, ItemStack added );

	protected @Nonnull IItemHandler getItemHandlerForSide( @Nonnull Direction side )
	{
		return this.getInternalInventory();
	}

	@SuppressWarnings("unchecked")
	@Nonnull
	@Override
	public <T> LazyOptional<T> getCapability(@Nonnull Capability<T> capability, Direction facing) {
		if( capability == CapabilityItemHandler.ITEM_HANDLER_CAPABILITY )
		{
			if( facing == null )
			{
				return (LazyOptional<T>) LazyOptional.of(this::getInternalInventory);
			}
			else
			{
				return (LazyOptional<T>) LazyOptional.of(() -> getItemHandlerForSide( facing ));
			}
		}
		return super.getCapability( capability, facing );
	}

}