ParserNBTList.java

package net.minecraft.command.type.custom.nbt;

import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;

import net.minecraft.command.CommandException;
import net.minecraft.command.ICommandSender;
import net.minecraft.command.ParsingUtilities;
import net.minecraft.command.SyntaxErrorException;
import net.minecraft.command.arg.CommandArg;
import net.minecraft.command.arg.PrimitiveParameter;
import net.minecraft.command.parser.Parser;
import net.minecraft.command.type.custom.nbt.NBTUtilities.NBTData;
import net.minecraft.nbt.NBTBase;
import net.minecraft.nbt.NBTTagList;

public class ParserNBTList
{
	private final NBTDescriptor.List descriptor;
	
	public ParserNBTList(final NBTDescriptor.List descriptor)
	{
		this.descriptor = descriptor;
	}
	
	public static class ListData extends NBTData
	{
		public final List<NBTBase> primitiveData = new ArrayList<>();
		public final ArrayList<CommandArg<NBTBase>> data = new ArrayList<>();
		
		@Override
		public void put(final NBTBase data)
		{
			if (this.data.isEmpty())
				this.primitiveData.add(data);
			else
				this.data.add(new PrimitiveParameter<>(data));
		}
		
		@Override
		public void add(final CommandArg<NBTBase> data)
		{
			this.data.add(data);
		}
		
	}
	
	public void parse(final Parser parser, final NBTData parserData) throws SyntaxErrorException
	{
		ParsingUtilities.terminateCompletion(parser);
		
		final ListData data = new ListData();
		
		this.parseItems(parser, data);
		
		if (data.data.isEmpty())
		{
			final NBTTagList list = new NBTTagList();
			
			for (final NBTBase item : data.primitiveData)
				list.appendTag(item);
			
			parserData.put(list);
		}
		else
		{
			final ArrayList<CommandArg<NBTBase>> dynamicData = data.data;
			dynamicData.trimToSize();
			
			if (data.primitiveData.isEmpty())
				parserData.add(new CommandArg<NBTBase>()
				{
					@Override
					public NBTTagList eval(final ICommandSender sender) throws CommandException
					{
						final NBTTagList list = new NBTTagList();
						
						for (final CommandArg<NBTBase> item : dynamicData)
							list.appendTag(item.eval(sender));
						
						return list;
					}
				});
			else
			{
				final NBTTagList list = new NBTTagList();
				for (final NBTBase item : data.primitiveData)
					list.appendTag(item);
				
				final int startIndex = data.primitiveData.size();
				
				parserData.add(new CommandArg<NBTBase>()
				{
					private boolean firstRun = true;
					
					@Override
					public NBTTagList eval(final ICommandSender sender) throws CommandException
					{
						if (this.firstRun)
						{
							this.firstRun = false;
							
							for (final CommandArg<NBTBase> item : dynamicData)
								list.appendTag(item.eval(sender));
						}
						else
						{
							int i = startIndex;
							
							for (final CommandArg<NBTBase> item : dynamicData)
								list.set(i++, item.eval(sender));
						}
						
						return list;
					}
				});
			}
			
		}
	}
	
	public void parseItems(final Parser parser, final ListData data) throws SyntaxErrorException
	{
		final Matcher m = parser.getMatcher(ParsingUtilities.listEndMatcher);
		
		for (int i = 0;; ++i)
		{
			if (parser.findInc(m)) // Because [Item1,Item2,] is valid... (or at least the output of NBTTagList.toString)
			{
				if (!"]".equals(m.group(1)))
					throw parser.SEE("Unexpected '" + m.group(1) + "' ");
				return;
			}
			
			this.descriptor.getTagDescriptor(i).getTagParser().parse(parser, data);
			
			if (!parser.findInc(m))
				throw parser.SEE("No delimiter found while parsing tag list ");
			
			if ("]".equals(m.group(1)))
				return;
			
			if ("}".equals(m.group(1)))
				throw parser.SEE("Unexpected '}' ");
		}
	}
}