package net.minecraft.server.commands;

import com.mojang.brigadier.CommandDispatcher;
import com.mojang.brigadier.arguments.IntegerArgumentType;
import com.mojang.brigadier.arguments.StringArgumentType;
import com.mojang.brigadier.exceptions.CommandSyntaxException;
import com.mojang.brigadier.exceptions.SimpleCommandExceptionType;
import java.util.Collection;
import java.util.List;
import net.minecraft.commands.CommandSourceStack;
import net.minecraft.commands.Commands;
import net.minecraft.commands.arguments.EntityArgument;
import net.minecraft.network.chat.Component;
import net.minecraft.network.protocol.common.ClientboundTransferPacket;
import net.minecraft.server.level.ServerPlayer;

public class TransferCommand {
	private static final SimpleCommandExceptionType ERROR_NO_PLAYERS = new SimpleCommandExceptionType(Component.translatable("commands.transfer.error.no_players"));

	public static void register(final CommandDispatcher<CommandSourceStack> dispatcher) {
		dispatcher.register(
			Commands.literal("transfer")
				.requires(Commands.hasPermission(Commands.LEVEL_ADMINS))
				.then(
					Commands.argument("hostname", StringArgumentType.string())
						.executes(c -> transfer(c.getSource(), StringArgumentType.getString(c, "hostname"), 25565, List.of(c.getSource().getPlayerOrException())))
						.then(
							Commands.argument("port", IntegerArgumentType.integer(1, 65535))
								.executes(
									c -> transfer(
										c.getSource(), StringArgumentType.getString(c, "hostname"), IntegerArgumentType.getInteger(c, "port"), List.of(c.getSource().getPlayerOrException())
									)
								)
								.then(
									Commands.argument("players", EntityArgument.players())
										.executes(
											c -> transfer(
												c.getSource(), StringArgumentType.getString(c, "hostname"), IntegerArgumentType.getInteger(c, "port"), EntityArgument.getPlayers(c, "players")
											)
										)
								)
						)
				)
		);
	}

	private static int transfer(final CommandSourceStack source, final String hostname, final int port, final Collection<ServerPlayer> players) throws CommandSyntaxException {
		if (players.isEmpty()) {
			throw ERROR_NO_PLAYERS.create();
		} else {
			for (ServerPlayer player : players) {
				player.connection.send(new ClientboundTransferPacket(hostname, port));
			}

			if (players.size() == 1) {
				source.sendSuccess(
					() -> Component.translatable("commands.transfer.success.single", ((ServerPlayer)players.iterator().next()).getDisplayName(), hostname, port), true
				);
			} else {
				source.sendSuccess(() -> Component.translatable("commands.transfer.success.multiple", players.size(), hostname, port), true);
			}

			return players.size();
		}
	}
}