package net.minecraft.server.commands;

import com.google.common.net.InetAddresses;
import com.mojang.brigadier.CommandDispatcher;
import com.mojang.brigadier.arguments.StringArgumentType;
import com.mojang.brigadier.exceptions.CommandSyntaxException;
import com.mojang.brigadier.exceptions.SimpleCommandExceptionType;
import java.util.List;
import net.minecraft.commands.CommandSourceStack;
import net.minecraft.commands.Commands;
import net.minecraft.commands.arguments.MessageArgument;
import net.minecraft.commands.arguments.selector.EntitySelector;
import net.minecraft.network.chat.Component;
import net.minecraft.server.level.ServerPlayer;
import net.minecraft.server.players.IpBanList;
import net.minecraft.server.players.IpBanListEntry;
import org.jspecify.annotations.Nullable;

public class BanIpCommands {
	private static final SimpleCommandExceptionType ERROR_INVALID_IP = new SimpleCommandExceptionType(Component.translatable("commands.banip.invalid"));
	private static final SimpleCommandExceptionType ERROR_ALREADY_BANNED = new SimpleCommandExceptionType(Component.translatable("commands.banip.failed"));

	public static void register(final CommandDispatcher<CommandSourceStack> dispatcher) {
		dispatcher.register(
			Commands.literal("ban-ip")
				.requires(Commands.hasPermission(Commands.LEVEL_ADMINS))
				.then(
					Commands.argument("target", StringArgumentType.word())
						.executes(c -> banIpOrName(c.getSource(), StringArgumentType.getString(c, "target"), null))
						.then(
							Commands.argument("reason", MessageArgument.message())
								.executes(c -> banIpOrName(c.getSource(), StringArgumentType.getString(c, "target"), MessageArgument.getMessage(c, "reason")))
						)
				)
		);
	}

	private static int banIpOrName(final CommandSourceStack source, final String target, @Nullable final Component reason) throws CommandSyntaxException {
		if (InetAddresses.isInetAddress(target)) {
			return banIp(source, target, reason);
		} else {
			ServerPlayer player = source.getServer().getPlayerList().getPlayerByName(target);
			if (player != null) {
				return banIp(source, player.getIpAddress(), reason);
			} else {
				throw ERROR_INVALID_IP.create();
			}
		}
	}

	private static int banIp(final CommandSourceStack source, final String ip, @Nullable final Component reason) throws CommandSyntaxException {
		IpBanList list = source.getServer().getPlayerList().getIpBans();
		if (list.isBanned(ip)) {
			throw ERROR_ALREADY_BANNED.create();
		} else {
			List<ServerPlayer> players = source.getServer().getPlayerList().getPlayersWithAddress(ip);
			IpBanListEntry entry = new IpBanListEntry(ip, null, source.getTextName(), null, reason == null ? null : reason.getString());
			list.add(entry);
			source.sendSuccess(() -> Component.translatable("commands.banip.success", ip, entry.getReasonMessage()), true);
			if (!players.isEmpty()) {
				source.sendSuccess(() -> Component.translatable("commands.banip.info", players.size(), EntitySelector.joinNames(players)), true);
			}

			for (ServerPlayer player : players) {
				player.connection.disconnect(Component.translatable("multiplayer.disconnect.ip_banned"));
			}

			return players.size();
		}
	}
}