Octobot/Boyfriend/CommandHandler.cs

using System.Text.RegularExpressions;
using Boyfriend.Commands;
using Discord;
using Discord.Commands;
using Discord.WebSocket;

namespace Boyfriend;

public static class CommandHandler {
    public static readonly Command[] Commands = {
        new BanCommand(), new ClearCommand(), new HelpCommand(),
        new KickCommand(), new MuteCommand(), new PingCommand(),
        new SettingsCommand(), new UnbanCommand(), new UnmuteCommand()
    };

    public static async Task HandleCommand(SocketUserMessage message) {
        var context = new SocketCommandContext(Boyfriend.Client, message);

        foreach (var command in Commands) {
            var regex = new Regex(Regex.Escape(Boyfriend.GetGuildConfig(context.Guild).Prefix!));
            if (!command.GetAliases().Contains(regex.Replace(message.Content, "", 1).Split()[0]))
                continue;

            var args = message.Content.Split().Skip(1).ToArray();
            try {
                if (command.GetArgumentsAmountRequired() > args.Length)
                    throw new ApplicationException(string.Format(Messages.NotEnoughArguments,
                        command.GetArgumentsAmountRequired(), args.Length));
                await command.Run(context, args);
            } catch (Exception e) {
                var signature = e switch {
                    ApplicationException => ":x:",
                    UnauthorizedAccessException => ":no_entry_sign:",
                    _ => ":stop_sign:"
                };
                var stacktrace = e.StackTrace;
                var toSend = $"{signature} `{e.Message}`";
                if (stacktrace != null && e is not ApplicationException && e is not UnauthorizedAccessException)
                    toSend += $"{Environment.NewLine}{Utils.Wrap(stacktrace)}";
                await context.Channel.SendMessageAsync(toSend);
                throw;
            }

            break;
        }
    }

    public static async Task CheckPermissions(IGuildUser user, GuildPermission toCheck,
        GuildPermission forBot = GuildPermission.StartEmbeddedActivities) {
        var me = await user.Guild.GetCurrentUserAsync();
        if (forBot == GuildPermission.StartEmbeddedActivities) forBot = toCheck;

        if (user.Id != user.Guild.OwnerId
            && (!me.GuildPermissions.Has(GuildPermission.Administrator)
                || !user.GuildPermissions.Has(GuildPermission.Administrator))) {
            if (!me.GuildPermissions.Has(forBot))
                throw new UnauthorizedAccessException(Messages.CommandNoPermissionBot);
            if (!user.GuildPermissions.Has(toCheck))
                throw new UnauthorizedAccessException(Messages.CommandNoPermissionUser);
        }
    }

    public static async Task CheckInteractions(IGuildUser actor, IGuildUser target) {
        var me = await target.Guild.GetCurrentUserAsync();

        if (actor.Guild != target.Guild)
            throw new Exception(Messages.InteractionsDifferentGuilds);
        if (actor.Id == actor.Guild.OwnerId) return;

        if (target.Id == target.Guild.OwnerId)
            throw new UnauthorizedAccessException(Messages.InteractionsOwner);
        if (actor == target)
            throw new UnauthorizedAccessException(Messages.InteractionsYourself);
        if (target == me)
            throw new UnauthorizedAccessException(Messages.InteractionsMe);
        if (me.Hierarchy <= target.Hierarchy)
            throw new UnauthorizedAccessException(Messages.InteractionsFailedBot);
        if (actor.Hierarchy <= target.Hierarchy)
            throw new UnauthorizedAccessException(Messages.InteractionsFailedUser);
    }
}