package appeng.fluids.helper;


import java.util.HashMap;
import java.util.Map;
import java.util.Objects;

import net.minecraft.entity.player.EntityPlayerMP;
import net.minecraft.inventory.IContainerListener;

import appeng.api.storage.data.IAEFluidStack;
import appeng.core.sync.network.NetworkHandler;
import appeng.core.sync.packets.PacketFluidSlot;
import appeng.fluids.util.AEFluidInventory;
import appeng.fluids.util.IAEFluidTank;


public class FluidSyncHelper
{
	private final IAEFluidTank inv;
	private final IAEFluidTank cache;
	private final int idOffset;

	public FluidSyncHelper( final IAEFluidTank inv, final int idOffset )
	{
		this.inv = inv;
		this.cache = new AEFluidInventory( null, inv.getSlots() );
		this.idOffset = idOffset;
	}

	public void sendFull( final Iterable<IContainerListener> listeners )
	{
		this.sendDiffMap( this.createDiffMap( true ), listeners );
	}

	public void sendDiff( final Iterable<IContainerListener> listeners )
	{
		this.sendDiffMap( this.createDiffMap( false ), listeners );
	}

	public void readPacket( final Map<Integer, IAEFluidStack> data )
	{
		for( int i = 0; i < this.inv.getSlots(); ++i )
		{
			if( data.containsKey( i + this.idOffset ) )
			{
				this.inv.setFluidInSlot( i, data.get( i + this.idOffset ) );
			}
		}
	}

	private void sendDiffMap( final Map<Integer, IAEFluidStack> data, final Iterable<IContainerListener> listeners )
	{
		if( data.isEmpty() )
		{
			return;
		}

		for( final IContainerListener l : listeners )
		{
			if( l instanceof EntityPlayerMP )
			{
				NetworkHandler.instance().sendTo( new PacketFluidSlot( data ), (EntityPlayerMP) l );
			}
		}
	}

	private final Map<Integer, IAEFluidStack> createDiffMap( final boolean full )
	{
		final Map<Integer, IAEFluidStack> ret = new HashMap<>();
		for( int i = 0; i < this.inv.getSlots(); ++i )
		{
			if( full || !this.equalsSlot( i ) )
			{
				ret.put( i + this.idOffset, this.inv.getFluidInSlot( i ) );
			}
			if( !full )
			{
				this.cache.setFluidInSlot( i, this.inv.getFluidInSlot( i ) );
			}
		}
		return ret;
	}

	private final boolean equalsSlot( int slot )
	{
		final IAEFluidStack stackA = this.inv.getFluidInSlot( slot );
		final IAEFluidStack stackB = this.cache.getFluidInSlot( slot );

		if( !Objects.equals( stackA, stackB ) )
		{
			return false;
		}

		return stackA == null || stackA.getStackSize() == stackB.getStackSize();
	}
}