Applied-Energistics-2/src/main/java/appeng/integration/modules/waila/part/ChannelWailaDataProvider.java

/*
 * 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.integration.modules.waila.part;

import java.util.List;

import net.minecraft.block.entity.BlockEntity;
import net.minecraft.nbt.CompoundTag;
import net.minecraft.server.network.ServerPlayerEntity;
import net.minecraft.text.Text;
import net.minecraft.util.math.BlockPos;
import net.minecraft.world.World;

import it.unimi.dsi.fastutil.objects.Object2ByteMap;
import it.unimi.dsi.fastutil.objects.Object2ByteOpenHashMap;
import mcp.mobius.waila.api.IDataAccessor;
import mcp.mobius.waila.api.IPluginConfig;

import appeng.api.parts.IPart;
import appeng.core.localization.WailaText;
import appeng.parts.networking.SmartCablePart;
import appeng.parts.networking.SmartDenseCablePart;

/**
 * Channel-information provider for WAILA
 *
 * @author thatsIch
 * @version rv2
 * @since rv2
 */
public final class ChannelWailaDataProvider extends BasePartWailaDataProvider {
    /**
     * Channel key used for the transferred {@link net.minecraft.nbt.CompoundTag}
     */
    private static final String ID_USED_CHANNELS = "usedChannels";

    /**
     * Used cache for channels if the channel was not transmitted through the
     * server.
     * <p/>
     * This is useful, when a player just started to look at a tile and thus just
     * requested the new information from the server.
     * <p/>
     * The cache will be updated from the server.
     */
    private final Object2ByteMap<IPart> cache = new Object2ByteOpenHashMap<>();

    /**
     * Adds the used and max channel to the tool tip
     *
     * @param part     being looked at part
     * @param tooltip  current tool tip
     * @param accessor wrapper for various world information
     * @param config   config to react to various settings
     */
    @Override
    public void appendBody(final IPart part, final List<Text> tooltip, final IDataAccessor accessor,
            final IPluginConfig config) {
        if (part instanceof SmartCablePart || part instanceof SmartDenseCablePart) {
            final CompoundTag tag = accessor.getServerData();

            final byte usedChannels = this.getUsedChannels(part, tag, this.cache);

            if (usedChannels >= 0) {
                final byte maxChannels = (byte) ((part instanceof SmartDenseCablePart) ? 32 : 8);

                final Text formattedToolTip = WailaText.Channels.text(usedChannels, maxChannels);
                tooltip.add(formattedToolTip);
            }
        }
    }

    /**
     * Determines the source of the channel.
     * <p/>
     * If the client received information of the channels on the server, they are
     * used, else if the cache contains a previous stored value, this will be used.
     * Default value is 0.
     *
     * @param part  part to be looked at
     * @param tag   tag maybe containing the channel information
     * @param cache cache with previous knowledge
     *
     * @return used channels on the cable
     */
    private byte getUsedChannels(final IPart part, final CompoundTag tag, final Object2ByteMap<IPart> cache) {
        final byte usedChannels;

        if (tag.contains(ID_USED_CHANNELS)) {
            usedChannels = tag.getByte(ID_USED_CHANNELS);
            this.cache.put(part, usedChannels);
        } else if (this.cache.containsKey(part)) {
            usedChannels = this.cache.get(part);
        } else {
            usedChannels = -1;
        }

        return usedChannels;
    }

    /**
     * Called on server to transfer information from server to client.
     * <p/>
     * If the part is a cable, it writes the channel information in the {@code #tag}
     * using the {@code ID_USED_CHANNELS} key.
     *
     * @param player player looking at the part
     * @param part   part being looked at
     * @param te     host of the part
     * @param tag    transferred tag which is send to the client
     * @param world  world of the part
     * @param pos    pos of the part
     */
    @Override
    public void appendServerData(ServerPlayerEntity player, IPart part, BlockEntity te, CompoundTag tag, World world,
            BlockPos pos) {
        if (part instanceof SmartCablePart || part instanceof SmartDenseCablePart) {
            final CompoundTag tempTag = new CompoundTag();

            part.writeToNBT(tempTag);

            if (tempTag.contains(ID_USED_CHANNELS)) {
                final byte usedChannels = tempTag.getByte(ID_USED_CHANNELS);

                tag.putByte(ID_USED_CHANNELS, usedChannels);
            }
        }
    }
}