minecraft-src/net/minecraft/commands/functions/MacroFunction.java

package net.minecraft.commands.functions;

import com.mojang.brigadier.CommandDispatcher;
import com.mojang.brigadier.StringReader;
import com.mojang.brigadier.exceptions.CommandSyntaxException;
import it.unimi.dsi.fastutil.ints.IntList;
import it.unimi.dsi.fastutil.ints.IntLists;
import it.unimi.dsi.fastutil.objects.Object2ObjectLinkedOpenHashMap;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import java.util.function.UnaryOperator;
import net.minecraft.Util;
import net.minecraft.commands.ExecutionCommandSource;
import net.minecraft.commands.FunctionInstantiationException;
import net.minecraft.commands.execution.UnboundEntryAction;
import net.minecraft.nbt.ByteTag;
import net.minecraft.nbt.CompoundTag;
import net.minecraft.nbt.DoubleTag;
import net.minecraft.nbt.FloatTag;
import net.minecraft.nbt.LongTag;
import net.minecraft.nbt.ShortTag;
import net.minecraft.nbt.StringTag;
import net.minecraft.nbt.Tag;
import net.minecraft.network.chat.Component;
import net.minecraft.resources.ResourceLocation;
import org.jetbrains.annotations.Nullable;

public class MacroFunction<T extends ExecutionCommandSource<T>> implements CommandFunction<T> {
	private static final DecimalFormat DECIMAL_FORMAT = Util.make(new DecimalFormat("#"), decimalFormat -> {
		decimalFormat.setMaximumFractionDigits(15);
		decimalFormat.setDecimalFormatSymbols(DecimalFormatSymbols.getInstance(Locale.US));
	});
	private static final int MAX_CACHE_ENTRIES = 8;
	private final List<String> parameters;
	private final Object2ObjectLinkedOpenHashMap<List<String>, InstantiatedFunction<T>> cache = new Object2ObjectLinkedOpenHashMap<>(8, 0.25F);
	private final ResourceLocation id;
	private final List<MacroFunction.Entry<T>> entries;

	public MacroFunction(ResourceLocation id, List<MacroFunction.Entry<T>> entries, List<String> parameters) {
		this.id = id;
		this.entries = entries;
		this.parameters = parameters;
	}

	@Override
	public ResourceLocation id() {
		return this.id;
	}

	@Override
	public InstantiatedFunction<T> instantiate(@Nullable CompoundTag arguments, CommandDispatcher<T> dispatcher) throws FunctionInstantiationException {
		if (arguments == null) {
			throw new FunctionInstantiationException(Component.translatable("commands.function.error.missing_arguments", Component.translationArg(this.id())));
		} else {
			List<String> list = new ArrayList(this.parameters.size());

			for (String string : this.parameters) {
				Tag tag = arguments.get(string);
				if (tag == null) {
					throw new FunctionInstantiationException(Component.translatable("commands.function.error.missing_argument", Component.translationArg(this.id()), string));
				}

				list.add(stringify(tag));
			}

			InstantiatedFunction<T> instantiatedFunction = this.cache.getAndMoveToLast(list);
			if (instantiatedFunction != null) {
				return instantiatedFunction;
			} else {
				if (this.cache.size() >= 8) {
					this.cache.removeFirst();
				}

				InstantiatedFunction<T> instantiatedFunction2 = this.substituteAndParse(this.parameters, list, dispatcher);
				this.cache.put(list, instantiatedFunction2);
				return instantiatedFunction2;
			}
		}
	}

	private static String stringify(Tag tag) {
		return switch (tag) {
			case FloatTag(float var24) -> DECIMAL_FORMAT.format(var24);
			case DoubleTag(double var25) -> DECIMAL_FORMAT.format(var25);
			case ByteTag(byte var26) -> String.valueOf(var26);
			case ShortTag(short var27) -> String.valueOf(var27);
			case LongTag(long var28) -> String.valueOf(var28);
			case StringTag(String var17) -> var17;
			default -> tag.toString();
		};
	}

	private static void lookupValues(List<String> arguments, IntList parameters, List<String> output) {
		output.clear();
		parameters.forEach(i -> output.add((String)arguments.get(i)));
	}

	private InstantiatedFunction<T> substituteAndParse(List<String> argumentNames, List<String> argumentValues, CommandDispatcher<T> dispatcher) throws FunctionInstantiationException {
		List<UnboundEntryAction<T>> list = new ArrayList(this.entries.size());
		List<String> list2 = new ArrayList(argumentValues.size());

		for (MacroFunction.Entry<T> entry : this.entries) {
			lookupValues(argumentValues, entry.parameters(), list2);
			list.add(entry.instantiate(list2, dispatcher, this.id));
		}

		return new PlainTextFunction<>(this.id().withPath((UnaryOperator<String>)(string -> string + "/" + argumentNames.hashCode())), list);
	}

	interface Entry<T> {
		IntList parameters();

		UnboundEntryAction<T> instantiate(List<String> arguments, CommandDispatcher<T> dispatcher, ResourceLocation function) throws FunctionInstantiationException;
	}

	static class MacroEntry<T extends ExecutionCommandSource<T>> implements MacroFunction.Entry<T> {
		private final StringTemplate template;
		private final IntList parameters;
		private final T compilationContext;

		public MacroEntry(StringTemplate template, IntList parameters, T compilationContext) {
			this.template = template;
			this.parameters = parameters;
			this.compilationContext = compilationContext;
		}

		@Override
		public IntList parameters() {
			return this.parameters;
		}

		@Override
		public UnboundEntryAction<T> instantiate(List<String> arguments, CommandDispatcher<T> dispatcher, ResourceLocation function) throws FunctionInstantiationException {
			String string = this.template.substitute(arguments);

			try {
				return CommandFunction.parseCommand(dispatcher, this.compilationContext, new StringReader(string));
			} catch (CommandSyntaxException var6) {
				throw new FunctionInstantiationException(
					Component.translatable("commands.function.error.parse", Component.translationArg(function), string, var6.getMessage())
				);
			}
		}
	}

	static class PlainTextEntry<T> implements MacroFunction.Entry<T> {
		private final UnboundEntryAction<T> compiledAction;

		public PlainTextEntry(UnboundEntryAction<T> compiledAction) {
			this.compiledAction = compiledAction;
		}

		@Override
		public IntList parameters() {
			return IntLists.emptyList();
		}

		@Override
		public UnboundEntryAction<T> instantiate(List<String> arguments, CommandDispatcher<T> dispatcher, ResourceLocation function) {
			return this.compiledAction;
		}
	}
}