discord-bot/CompatBot/Commands/ForcedNicknames.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using CompatBot.Commands.Attributes;
using CompatBot.Database;
using CompatBot.EventHandlers;
using CompatBot.Utils;
using CompatBot.Utils.Extensions;
using DSharpPlus;
using DSharpPlus.CommandsNext;
using DSharpPlus.CommandsNext.Attributes;
using DSharpPlus.Entities;
using Microsoft.EntityFrameworkCore;

namespace CompatBot.Commands
{
    [Group("rename")]
    [Description("Manage users who has forced nickname.")]
    internal sealed class ForcedNicknames : BaseCommandModuleCustom
    {
        [GroupCommand]
        [Description("Enforces specific nickname for particular user.")]
        public async Task Rename(CommandContext ctx,
            [Description("Discord user to add to forced nickname list.")] DiscordUser discordUser, 
            [Description("Nickname which should be displayed."), RemainingText] string expectedNickname)
        {
            if (!await new RequiresBotModRole().ExecuteCheckAsync(ctx, false).ConfigureAwait(false))
                return;
            
            try
            {
                if (expectedNickname.Length is < 2 or > 32)
                {
                    await ctx.ReactWithAsync(Config.Reactions.Failure, "Nickname must be between 2 and 32 characters long", true).ConfigureAwait(false);
                    return;
                }

                if ((!expectedNickname.All(c => char.IsLetterOrDigit(c)
                                                || char.IsWhiteSpace(c)
                                                || char.IsPunctuation(c))
                     || expectedNickname.Any(c => c is ':' or '#' or '@' or '`')
                    ) && !discordUser.IsBotSafeCheck())
                {
                    await ctx.ReactWithAsync(Config.Reactions.Failure, "Nickname must follow Rule 7", true).ConfigureAwait(false);
                    return;
                }

                List<DiscordGuild> guilds;
                if (ctx.Guild == null)
                {
                    guilds = ctx.Client.Guilds?.Values.ToList() ?? new List<DiscordGuild>(0);
                    if (guilds.Count > 1)
                        await ctx.Channel.SendMessageAsync($"{discordUser.Mention} will be renamed in all {guilds.Count} servers").ConfigureAwait(false);
                }
                else
                    guilds = new(){ctx.Guild};

                int changed = 0, noPermissions = 0, failed = 0;
                await using var db = new BotDb();
                foreach (var guild in guilds)
                {
                    if (!discordUser.IsBotSafeCheck())
                    {
                        var enforceRules = db.ForcedNicknames.FirstOrDefault(mem => mem.UserId == discordUser.Id && mem.GuildId == guild.Id);
                        if (enforceRules is null)
                        {
                            enforceRules = new() {UserId = discordUser.Id, GuildId = guild.Id, Nickname = expectedNickname};
                            await db.ForcedNicknames.AddAsync(enforceRules).ConfigureAwait(false);
                        }
                        else
                        {
                            if (enforceRules.Nickname == expectedNickname)
                            {
                                continue;
                            }
                            enforceRules.Nickname = expectedNickname;
                        }
                    }
                    if (!(ctx.Guild?.Permissions?.HasFlag(Permissions.ChangeNickname) ?? true))
                    {
                        noPermissions++;
                        continue;
                    }

                    if (ctx.Client.GetMember(guild, discordUser) is DiscordMember discordMember)
                        try
                        {
                            await discordMember.ModifyAsync(x => x.Nickname = expectedNickname).ConfigureAwait(false);
                            changed++;
                        }
                        catch (Exception ex)
                        {
                            Config.Log.Warn(ex, "Failed to change nickname");
                            failed++;
                        }
                }
                await db.SaveChangesAsync().ConfigureAwait(false);
                if (guilds.Count > 1)
                {
                    if (changed > 0)
                        await ctx.ReactWithAsync(Config.Reactions.Success, $"Forced nickname for {discordUser.Mention} in {changed} server{(changed == 1 ? "" : "s")}", true).ConfigureAwait(false);
                    else
                        await ctx.ReactWithAsync(Config.Reactions.Failure, $"Failed to force nickname for {discordUser.Mention} in any server").ConfigureAwait(false);
                }
                else
                {
                    if (changed > 0)
                        await ctx.ReactWithAsync(Config.Reactions.Success, $"Forced nickname for {discordUser.Mention}", true).ConfigureAwait(false);
                    else if (failed > 0)
                        await ctx.ReactWithAsync(Config.Reactions.Failure, $"Failed to force nickname for {discordUser.Mention}").ConfigureAwait(false);
                    else if (noPermissions > 0)
                        await ctx.ReactWithAsync(Config.Reactions.Failure, $"No permissions to force nickname for {discordUser.Mention}").ConfigureAwait(false);
                }
            }
            catch (Exception e)
            {
                Config.Log.Error(e);
                await ctx.ReactWithAsync(Config.Reactions.Failure, "Failed to change nickname, check bot's permissions").ConfigureAwait(false);
            }
        }

        [Command("clear"), Aliases("remove"), RequiresBotModRole]
        [Description("Removes nickname restriction from particular user.")]
        public async Task Remove(CommandContext ctx, [Description("Discord user to remove from forced nickname list.")] DiscordUser discordUser)
        {
            try
            {
                if (discordUser.IsBotSafeCheck())
                {
                    var mem = ctx.Client.GetMember(ctx.Guild.Id, discordUser);
                    if (mem is not null)
                    {
                        await mem.ModifyAsync(m => m.Nickname = new(discordUser.Username)).ConfigureAwait(false);
                        await ctx.ReactWithAsync(Config.Reactions.Success).ConfigureAwait(false);
                    }
                    return;
                }
                
                await using var db = new BotDb();
                var enforcedRules = ctx.Guild == null
                    ? await db.ForcedNicknames.Where(mem => mem.UserId == discordUser.Id).ToListAsync().ConfigureAwait(false)
                    : await db.ForcedNicknames.Where(mem => mem.UserId == discordUser.Id && mem.GuildId == ctx.Guild.Id).ToListAsync().ConfigureAwait(false);
                if (enforcedRules.Count == 0)
                    return;
                
                db.ForcedNicknames.RemoveRange(enforcedRules);
                await db.SaveChangesAsync().ConfigureAwait(false);
                foreach (var rule in enforcedRules)
                    if (ctx.Client.GetMember(rule.GuildId, discordUser) is DiscordMember discordMember)
                        try
                        {
                            //todo: change to mem.Nickname = default when the library fixes their shit
                            await discordMember.ModifyAsync(mem => mem.Nickname = new(discordMember.Username)).ConfigureAwait(false);
                        }
                        catch (Exception ex)
                        {
                            Config.Log.Debug(ex);
                        }
                await ctx.ReactWithAsync(Config.Reactions.Success).ConfigureAwait(false);
            }
            catch (Exception e)
            {
                Config.Log.Error(e);
                await ctx.ReactWithAsync(Config.Reactions.Failure, "Failed to reset user nickname").ConfigureAwait(false);
            }
        }

        [Command("cleanup"), Aliases("clean", "fix"), RequiresBotModRole]
        [Description("Removes zalgo from specified user nickname")]
        public async Task Cleanup(CommandContext ctx, [Description("Discord user to clean up")] DiscordMember discordUser)
        {
            var name = discordUser.DisplayName;
            var newName = UsernameZalgoMonitor.StripZalgo(name, discordUser.Username, discordUser.Id);
            if (name == newName)
                await ctx.Channel.SendMessageAsync("Failed to remove any extra symbols").ConfigureAwait(false);
            else
            {
                try
                {
                    await discordUser.ModifyAsync(m => m.Nickname = new(newName)).ConfigureAwait(false);
                    await ctx.ReactWithAsync(Config.Reactions.Success, $"Renamed user to {newName}", true).ConfigureAwait(false);
                }
                catch (Exception)
                {
                    Config.Log.Warn($"Failed to rename user {discordUser.Username}#{discordUser.Discriminator}");
                    await ctx.ReactWithAsync(Config.Reactions.Failure, $"Failed to rename user to {newName}").ConfigureAwait(false);
                }
            }
        }

        [Command("dump")]
        [Description("Prints hexadecimal binary representation of an UTF-8 encoded user name for diagnostic purposes")]
        public async Task Dump(CommandContext ctx, [Description("Discord user to dump")] DiscordUser discordUser)
        {
            var name = discordUser.Username;
            var nameBytes = StringUtils.Utf8.GetBytes(name);
            var hex = BitConverter.ToString(nameBytes).Replace('-', ' ');
            var result = $"User ID: {discordUser.Id}\nUsername: {hex}";
            var member = ctx.Client.GetMember(ctx.Guild, discordUser);
            if (member?.Nickname is string {Length: >0} nickname)
            {
                nameBytes = StringUtils.Utf8.GetBytes(nickname);
                hex = BitConverter.ToString(nameBytes).Replace('-', ' ');
                result += "\nNickname: " + hex;
            }
            await ctx.Channel.SendMessageAsync(result).ConfigureAwait(false);
        }

        [Command("generate"), Aliases("gen", "suggest")]
        [Description("Generates random name for specified user")]
        public async Task Generate(CommandContext ctx, [Description("Discord user to dump")] DiscordUser discordUser)
        {
            var newName = UsernameZalgoMonitor.GenerateRandomName(discordUser.Id);
            await ctx.Channel.SendMessageAsync(newName).ConfigureAwait(false);
        }
        
        [Command("list"), RequiresBotModRole]
        [Description("Lists all users who has restricted nickname.")]
        public async Task List(CommandContext ctx)
        {
            await using var db = new BotDb();
            var selectExpr = db.ForcedNicknames.AsNoTracking();
            if (ctx.Guild != null)
                selectExpr = selectExpr.Where(mem => mem.GuildId == ctx.Guild.Id);

            var forcedNicknames = (
                from m in selectExpr.AsEnumerable()
                orderby m.UserId, m.Nickname
                let result = new {m.UserId, m.Nickname}
                select result
            ).ToList();
            if (forcedNicknames.Count == 0)
            {
                await ctx.Channel.SendMessageAsync("No users with forced nicknames").ConfigureAwait(false);
                return;
            }

            var table = new AsciiTable(
                new AsciiColumn("ID", !ctx.Channel.IsPrivate || !ctx.User.IsWhitelisted(ctx.Client)),
                new AsciiColumn("Username"),
                new AsciiColumn("Forced nickname")
            );
            var previousUser = 0ul;
            foreach (var forcedNickname in forcedNicknames.Distinct())
            {
                var sameUser = forcedNickname.UserId == previousUser;
                var username = sameUser ? "" : await ctx.GetUserNameAsync(forcedNickname.UserId).ConfigureAwait(false);
                table.Add( sameUser ? "" : forcedNickname.UserId.ToString(), username, forcedNickname.Nickname);
                previousUser = forcedNickname.UserId;
            }
            await ctx.SendAutosplitMessageAsync(table.ToString()).ConfigureAwait(false);
        } 
    }
}