minecraft-src/net/minecraft/commands/arguments/EntityArgument.java

package net.minecraft.commands.arguments;

import com.google.common.collect.Iterables;
import com.google.gson.JsonObject;
import com.mojang.brigadier.StringReader;
import com.mojang.brigadier.arguments.ArgumentType;
import com.mojang.brigadier.context.CommandContext;
import com.mojang.brigadier.exceptions.CommandSyntaxException;
import com.mojang.brigadier.exceptions.SimpleCommandExceptionType;
import com.mojang.brigadier.suggestion.Suggestions;
import com.mojang.brigadier.suggestion.SuggestionsBuilder;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import net.minecraft.commands.CommandBuildContext;
import net.minecraft.commands.CommandSourceStack;
import net.minecraft.commands.SharedSuggestionProvider;
import net.minecraft.commands.arguments.selector.EntitySelector;
import net.minecraft.commands.arguments.selector.EntitySelectorParser;
import net.minecraft.commands.synchronization.ArgumentTypeInfo;
import net.minecraft.network.FriendlyByteBuf;
import net.minecraft.network.chat.Component;
import net.minecraft.server.level.ServerPlayer;
import net.minecraft.world.entity.Entity;

public class EntityArgument implements ArgumentType<EntitySelector> {
	private static final Collection<String> EXAMPLES = Arrays.asList("Player", "0123", "@e", "@e[type=foo]", "dd12be42-52a9-4a91-a8a1-11c01849e498");
	public static final SimpleCommandExceptionType ERROR_NOT_SINGLE_ENTITY = new SimpleCommandExceptionType(Component.translatable("argument.entity.toomany"));
	public static final SimpleCommandExceptionType ERROR_NOT_SINGLE_PLAYER = new SimpleCommandExceptionType(Component.translatable("argument.player.toomany"));
	public static final SimpleCommandExceptionType ERROR_ONLY_PLAYERS_ALLOWED = new SimpleCommandExceptionType(Component.translatable("argument.player.entities"));
	public static final SimpleCommandExceptionType NO_ENTITIES_FOUND = new SimpleCommandExceptionType(Component.translatable("argument.entity.notfound.entity"));
	public static final SimpleCommandExceptionType NO_PLAYERS_FOUND = new SimpleCommandExceptionType(Component.translatable("argument.entity.notfound.player"));
	public static final SimpleCommandExceptionType ERROR_SELECTORS_NOT_ALLOWED = new SimpleCommandExceptionType(
		Component.translatable("argument.entity.selector.not_allowed")
	);
	final boolean single;
	final boolean playersOnly;

	protected EntityArgument(boolean single, boolean playersOnly) {
		this.single = single;
		this.playersOnly = playersOnly;
	}

	public static EntityArgument entity() {
		return new EntityArgument(true, false);
	}

	public static Entity getEntity(CommandContext<CommandSourceStack> context, String name) throws CommandSyntaxException {
		return context.<EntitySelector>getArgument(name, EntitySelector.class).findSingleEntity(context.getSource());
	}

	public static EntityArgument entities() {
		return new EntityArgument(false, false);
	}

	public static Collection<? extends Entity> getEntities(CommandContext<CommandSourceStack> context, String name) throws CommandSyntaxException {
		Collection<? extends Entity> collection = getOptionalEntities(context, name);
		if (collection.isEmpty()) {
			throw NO_ENTITIES_FOUND.create();
		} else {
			return collection;
		}
	}

	public static Collection<? extends Entity> getOptionalEntities(CommandContext<CommandSourceStack> context, String name) throws CommandSyntaxException {
		return context.<EntitySelector>getArgument(name, EntitySelector.class).findEntities(context.getSource());
	}

	public static Collection<ServerPlayer> getOptionalPlayers(CommandContext<CommandSourceStack> context, String name) throws CommandSyntaxException {
		return context.<EntitySelector>getArgument(name, EntitySelector.class).findPlayers(context.getSource());
	}

	public static EntityArgument player() {
		return new EntityArgument(true, true);
	}

	public static ServerPlayer getPlayer(CommandContext<CommandSourceStack> context, String name) throws CommandSyntaxException {
		return context.<EntitySelector>getArgument(name, EntitySelector.class).findSinglePlayer(context.getSource());
	}

	public static EntityArgument players() {
		return new EntityArgument(false, true);
	}

	public static Collection<ServerPlayer> getPlayers(CommandContext<CommandSourceStack> context, String name) throws CommandSyntaxException {
		List<ServerPlayer> list = context.<EntitySelector>getArgument(name, EntitySelector.class).findPlayers(context.getSource());
		if (list.isEmpty()) {
			throw NO_PLAYERS_FOUND.create();
		} else {
			return list;
		}
	}

	public EntitySelector parse(StringReader reader) throws CommandSyntaxException {
		return this.parse(reader, true);
	}

	public <S> EntitySelector parse(StringReader reader, S suggestionProvider) throws CommandSyntaxException {
		return this.parse(reader, EntitySelectorParser.allowSelectors(suggestionProvider));
	}

	private EntitySelector parse(StringReader reader, boolean allowSelectors) throws CommandSyntaxException {
		int i = 0;
		EntitySelectorParser entitySelectorParser = new EntitySelectorParser(reader, allowSelectors);
		EntitySelector entitySelector = entitySelectorParser.parse();
		if (entitySelector.getMaxResults() > 1 && this.single) {
			if (this.playersOnly) {
				reader.setCursor(0);
				throw ERROR_NOT_SINGLE_PLAYER.createWithContext(reader);
			} else {
				reader.setCursor(0);
				throw ERROR_NOT_SINGLE_ENTITY.createWithContext(reader);
			}
		} else if (entitySelector.includesEntities() && this.playersOnly && !entitySelector.isSelfSelector()) {
			reader.setCursor(0);
			throw ERROR_ONLY_PLAYERS_ALLOWED.createWithContext(reader);
		} else {
			return entitySelector;
		}
	}

	@Override
	public <S> CompletableFuture<Suggestions> listSuggestions(CommandContext<S> commandContext, SuggestionsBuilder suggestionsBuilder) {
		if (commandContext.getSource() instanceof SharedSuggestionProvider sharedSuggestionProvider) {
			StringReader stringReader = new StringReader(suggestionsBuilder.getInput());
			stringReader.setCursor(suggestionsBuilder.getStart());
			EntitySelectorParser entitySelectorParser = new EntitySelectorParser(stringReader, EntitySelectorParser.allowSelectors(sharedSuggestionProvider));

			try {
				entitySelectorParser.parse();
			} catch (CommandSyntaxException var7) {
			}

			return entitySelectorParser.fillSuggestions(
				suggestionsBuilder,
				suggestionsBuilderx -> {
					Collection<String> collection = sharedSuggestionProvider.getOnlinePlayerNames();
					Iterable<String> iterable = (Iterable<String>)(this.playersOnly
						? collection
						: Iterables.concat(collection, sharedSuggestionProvider.getSelectedEntities()));
					SharedSuggestionProvider.suggest(iterable, suggestionsBuilderx);
				}
			);
		} else {
			return Suggestions.empty();
		}
	}

	@Override
	public Collection<String> getExamples() {
		return EXAMPLES;
	}

	public static class Info implements ArgumentTypeInfo<EntityArgument, EntityArgument.Info.Template> {
		private static final byte FLAG_SINGLE = 1;
		private static final byte FLAG_PLAYERS_ONLY = 2;

		public void serializeToNetwork(EntityArgument.Info.Template template, FriendlyByteBuf buffer) {
			int i = 0;
			if (template.single) {
				i |= 1;
			}

			if (template.playersOnly) {
				i |= 2;
			}

			buffer.writeByte(i);
		}

		public EntityArgument.Info.Template deserializeFromNetwork(FriendlyByteBuf buffer) {
			byte b = buffer.readByte();
			return new EntityArgument.Info.Template((b & 1) != 0, (b & 2) != 0);
		}

		public void serializeToJson(EntityArgument.Info.Template template, JsonObject json) {
			json.addProperty("amount", template.single ? "single" : "multiple");
			json.addProperty("type", template.playersOnly ? "players" : "entities");
		}

		public EntityArgument.Info.Template unpack(EntityArgument argument) {
			return new EntityArgument.Info.Template(argument.single, argument.playersOnly);
		}

		public final class Template implements ArgumentTypeInfo.Template<EntityArgument> {
			final boolean single;
			final boolean playersOnly;

			Template(final boolean single, final boolean playersOnly) {
				this.single = single;
				this.playersOnly = playersOnly;
			}

			public EntityArgument instantiate(CommandBuildContext context) {
				return new EntityArgument(this.single, this.playersOnly);
			}

			@Override
			public ArgumentTypeInfo<EntityArgument, ?> type() {
				return Info.this;
			}
		}
	}
}