equivalent-exchange-3/src/main/java/com/pahimar/ee3/command/CommandPlayerForgetItem.java

package com.pahimar.ee3.command;

import java.util.List;

import com.pahimar.ee3.api.knowledge.PlayerKnowledgeRegistryProxy;
import com.pahimar.ee3.reference.Messages;
import com.pahimar.ee3.reference.Names;
import cpw.mods.fml.common.FMLCommonHandler;
import net.minecraft.command.CommandBase;
import net.minecraft.command.ICommandSender;
import net.minecraft.command.WrongUsageException;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.nbt.JsonToNBT;
import net.minecraft.nbt.NBTBase;
import net.minecraft.nbt.NBTTagCompound;

public class CommandPlayerForgetItem extends CommandBase {
    @Override
    public String getCommandName() {
        return Names.Commands.PLAYER_FORGET_ITEM;
    }

    @Override
    public int getRequiredPermissionLevel() {
        return 2;
    }

    @Override
    public String getCommandUsage(ICommandSender commandSender) {
        return Messages.Commands.PLAYER_FORGET_ITEM_USAGE;
    }

    @Override
    public void processCommand(ICommandSender commandSender, String[] args) {
        if (args.length < 3) {
            throw new WrongUsageException(Messages.Commands.PLAYER_FORGET_ITEM_USAGE);
        } else {
            EntityPlayer entityPlayer = getPlayer(commandSender, args[1]);

            if (entityPlayer != null) {
                Item item = getItemByText(commandSender, args[2]);
                int metaData = 0;

                if (args.length >= 4) {
                    metaData = parseInt(commandSender, args[3]);
                }

                ItemStack itemStack = new ItemStack(item, 1, metaData);

                if (args.length >= 5) {
                    String stringNBTData
                        = func_147178_a(commandSender, args, 4).getUnformattedText();

                    try {
                        NBTBase nbtBase = JsonToNBT.func_150315_a(stringNBTData);

                        if (!(nbtBase instanceof NBTTagCompound)) {
                            func_152373_a(
                                commandSender,
                                this,
                                Messages.Commands.INVALID_NBT_TAG_ERROR,
                                new Object[] { "Not a valid tag" }
                            );
                            return;
                        }

                        itemStack.setTagCompound((NBTTagCompound) nbtBase);
                    } catch (Exception exception) {
                        func_152373_a(
                            commandSender,
                            this,
                            Messages.Commands.INVALID_NBT_TAG_ERROR,
                            new Object[] { exception.getMessage() }
                        );
                        return;
                    }
                }

                PlayerKnowledgeRegistryProxy.makePlayerForget(entityPlayer, itemStack);
                func_152373_a(
                    commandSender,
                    this,
                    Messages.Commands.PLAYER_FORGET_ITEM_SUCCESS,
                    new Object[] { commandSender.getCommandSenderName(),
                                   entityPlayer.getCommandSenderName(),
                                   itemStack.func_151000_E() }
                );
            } else {
                throw new WrongUsageException(Messages.Commands.PLAYER_NOT_FOUND_ERROR);
            }
        }
    }

    @Override
    public List addTabCompletionOptions(ICommandSender commandSender, String[] args) {
        if (args.length == 2) {
            return getListOfStringsMatchingLastWord(
                args,
                FMLCommonHandler.instance().getMinecraftServerInstance().getAllUsernames()
            );
        } else if (args.length == 3) {
            return getListOfStringsFromIterableMatchingLastWord(
                args, Item.itemRegistry.getKeys()
            );
        }

        return null;
    }
}