ReactionHandler.cs

using ArmaforcesMissionBot.DataClasses;
using Discord;
using Discord.WebSocket;
using Microsoft.Extensions.DependencyInjection;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Timers;
using ArmaforcesMissionBot.Helpers;


namespace ArmaforcesMissionBot.Handlers
{
    public static class StringExtensionMethods
    {
        public static string ReplaceFirst(this string text, string search, string replace)
        {
            int pos = text.IndexOf(search);
            if (pos < 0)
            {
                return text;
            }
            return text.Substring(0, pos) + replace + text.Substring(pos + search.Length);
        }
    }
    public class ReactionHandler : IInstallable
    {
        private DiscordSocketClient _client;
        private MiscHelper _miscHelper;
        private IServiceProvider _services;
        private Config _config;
        private Timer _timer;

        public async Task Install(IServiceProvider map)
        {
            _client = map.GetService<DiscordSocketClient>();
            _config = map.GetService<Config>();
            _miscHelper = map.GetService<MiscHelper>();
            _services = map;
            // Hook the MessageReceived event into our command handler
            _client.ReactionAdded += HandleReactionAdded;
            _client.ReactionRemoved += HandleReactionRemoved;

            _timer = new Timer();
            _timer.Interval = 2000;

            _timer.Elapsed += CheckReactionTimes;
            _timer.AutoReset = true;
            _timer.Enabled = true;
        }

        private async Task HandleReactionAdded(Cacheable<IUserMessage, ulong> message, ISocketMessageChannel channel, SocketReaction reaction)
        {
            var signups = _services.GetService<SignupsData>();

            if (reaction.User.IsSpecified && !reaction.User.Value.IsBot && _config.RoleAssignChannel == channel.Id)
            {
                await AddedReactionInRolesChannel(message, channel, reaction);
            }
            else if (reaction.User.IsSpecified && !reaction.User.Value.IsBot && signups.Missions.Any(x => x.SignupChannel == channel.Id))
            {
                await AddedReactionInSignupsChannel(message, channel, reaction, signups);
            }
            else if (signups.Missions.Any(x => x.SignupChannel == channel.Id) && reaction.UserId != _client.CurrentUser.Id)
            {
                var user = _client.GetUser(reaction.UserId);
                Console.WriteLine($"Naprawiam reakcje po spamie {user.Username}");
                var teamMsg = await channel.GetMessageAsync(message.Id) as IUserMessage;
                await teamMsg.RemoveReactionAsync(reaction.Emote, user);
            }
        }

        private async Task HandleReactionRemoved(Cacheable<IUserMessage, ulong> message, ISocketMessageChannel channel, SocketReaction reaction)
        {
            var signups = _services.GetService<SignupsData>();

            if (reaction.User.IsSpecified && !reaction.User.Value.IsBot && _config.RoleAssignChannel == channel.Id)
            {
                await RemovedReactionInRolesChannel(message, channel, reaction);
            }
            else if (signups.Missions.Any(x => x.SignupChannel == channel.Id))
            {
                await RemovedReactionInSignupsChannel(message, channel, reaction, signups);
            }
        }

        private async Task HandleReactionChange(Cacheable<IUserMessage, ulong> message, ISocketMessageChannel channel, SocketReaction reaction, SignupsData signups)
        {
            await signups.BanAccess.WaitAsync(-1);
            try
            {
                if (!signups.ReactionTimes.ContainsKey(reaction.User.Value.Id))
                {
                    signups.ReactionTimes[reaction.User.Value.Id] = new Queue<DateTime>();
                }

                signups.ReactionTimes[reaction.User.Value.Id].Enqueue(DateTime.Now);

                Console.WriteLine($"[{DateTime.Now.ToString()}] {reaction.User.Value.Username} spam counter: {signups.ReactionTimes[reaction.User.Value.Id].Count}");

                if (signups.ReactionTimes[reaction.User.Value.Id].Count >= 10 && !signups.SpamBans.ContainsKey(reaction.User.Value.Id))
                {
                    await Helpers.BanHelper.BanUserSpam(_services, reaction.User.Value);
                }
            }
            finally
            {
                signups.BanAccess.Release();
            }
        }

        private async void CheckReactionTimes(object source, ElapsedEventArgs e)
        {
            var signups = _services.GetService<SignupsData>();

            await signups.BanAccess.WaitAsync(-1);
            try
            {
                foreach (var user in signups.ReactionTimes)
                {
                    while (user.Value.Count > 0 && user.Value.Peek() < e.SignalTime.AddSeconds(-30))
                        user.Value.Dequeue();
                }
            }
            finally
            {
                signups.BanAccess.Release();
            }
        }

        private async Task AddedReactionInSignupsChannel(Cacheable<IUserMessage, ulong> message, ISocketMessageChannel channel, SocketReaction reaction, SignupsData signups)
        {
            var reactionStringAnimatedVersion = reaction.Emote.ToString().Insert(1, "a");

            var mission = signups.Missions.Single(x => x.SignupChannel == channel.Id);

            await HandleReactionChange(message, channel, reaction, signups);
            Console.WriteLine($"[{DateTime.Now.ToString()}] {reaction.User.Value.Username} added reaction {reaction.Emote.Name}");

            if (signups.SignupBans.ContainsKey(reaction.User.Value.Id) && signups.SignupBans[reaction.User.Value.Id] > mission.Date)
            {
                await reaction.User.Value.SendMessageAsync("Masz bana na zapisy, nie mo¿esz zapisaæ siê na misjê, która odbêdzie siê w czasie trwania bana.");
                var teamMsg = await channel.GetMessageAsync(message.Id) as IUserMessage;
                await teamMsg.RemoveReactionAsync(reaction.Emote, reaction.User.Value);
                return;
            }

            await mission.Access.WaitAsync(-1);
            try
            {
                if (mission.Teams.Any(x => x.TeamMsg == message.Id))
                {
                    var team = mission.Teams.Single(x => x.TeamMsg == message.Id);
                    if (team.Slots.Any(x => (x.Emoji == reaction.Emote.ToString() || x.Emoji == reactionStringAnimatedVersion) && (x.Count > x.Signed.Count() || team.Reserve != 0)))
                    {
                        var teamMsg = await channel.GetMessageAsync(message.Id) as IUserMessage;

                        var embed = teamMsg.Embeds.Single();

                        if (!mission.SignedUsers.Any(x => x == reaction.User.Value.Id))
                        {
                            var slot = team.Slots.Single(x => x.Emoji == reaction.Emote.ToString() || x.Emoji == reactionStringAnimatedVersion);
                            if (!slot.Signed.Contains(reaction.User.Value.Id))
                                slot.Signed.Add(reaction.User.Value.Id);
                            if (!mission.SignedUsers.Contains(reaction.User.Value.Id))
                                mission.SignedUsers.Add(reaction.User.Value.Id);

                            var newDescription = _miscHelper.BuildTeamSlots(team);

                            var newEmbed = new EmbedBuilder
                            {
                                Title = team.Name,
                                Color = embed.Color
                            };

                            if (newDescription.Count == 2)
                                newEmbed.WithDescription(newDescription[0] + newDescription[1]);
                            else if (newDescription.Count == 1)
                                newEmbed.WithDescription(newDescription[0]);

                            if (embed.Footer.HasValue)
                                newEmbed.WithFooter(embed.Footer.Value.Text);
                            else
                                newEmbed.WithFooter(team.Pattern);

                            await teamMsg.ModifyAsync(x => x.Embed = newEmbed.Build());
                        }
                        else
                        {
                            await teamMsg.RemoveReactionAsync(reaction.Emote, reaction.User.Value);
                        }
                    }
                    else if (team.Slots.Any(x => x.Emoji == reaction.Emote.ToString()))
                    {
                        var teamMsg = await channel.GetMessageAsync(message.Id) as IUserMessage;
                        await teamMsg.RemoveReactionAsync(reaction.Emote, reaction.User.Value);
                    }
                }
            }
            finally
            {
                mission.Access.Release();
            }
        }

        private async Task AddedReactionInRolesChannel(Cacheable<IUserMessage, ulong> message, ISocketMessageChannel channel, SocketReaction reaction)
        {
            var fullMessage = await channel.GetMessageAsync(message.Id) as IUserMessage;

            var messageDescription = fullMessage.Embeds.Single().Description;
            ulong rank;
            var reactionsMatches = MiscHelper.GetRankArrayMatchesFromText(messageDescription);
            var rankForEmoji = reactionsMatches.Find(x => x.Item1 == reaction.Emote.ToString());

            try
            {
                string regexPattern = @"\<\@\&([0-9]+)\>";
                var rankMatches = Regex.Matches(rankForEmoji.Item2, regexPattern, RegexOptions.IgnoreCase | RegexOptions.RightToLeft).First().ToString();
                rank = ulong.Parse(Regex.Matches(rankMatches, "[0-9]+", RegexOptions.IgnoreCase | RegexOptions.RightToLeft).First().Value);
            }
            catch (Exception e)
            {
                Console.WriteLine($"Parsing ranks failed.");
                return;
            }

            try
            {
                var role = (channel as SocketGuildChannel).Guild.GetRole(rank);

                await (reaction.User.Value as SocketGuildUser).AddRoleAsync(role);

            }
            catch (Exception ex)
            {
                Console.WriteLine($"Adding rank failed.");
            }

            return;
        }

        private async Task RemovedReactionInSignupsChannel(Cacheable<IUserMessage, ulong> message, ISocketMessageChannel channel, SocketReaction reaction, SignupsData signups)
        {
            var reactionStringAnimatedVersion = reaction.Emote.ToString().Insert(1, "a");

            var mission = signups.Missions.Single(x => x.SignupChannel == channel.Id);
            var user = await (channel as IGuildChannel).Guild.GetUserAsync(reaction.UserId);

            Console.WriteLine($"[{DateTime.Now.ToString()}] {user.Username} removed reaction {reaction.Emote.Name}");

            await mission.Access.WaitAsync(-1);
            try
            {
                if (mission.Teams.Any(x => x.TeamMsg == message.Id))
                {
                    var team = mission.Teams.Single(x => x.TeamMsg == message.Id);
                    if (team.Slots.Any(x => (x.Emoji == reaction.Emote.ToString() || x.Emoji == reactionStringAnimatedVersion) && x.Signed.Contains(user.Id)))
                    {
                        var teamMsg = await channel.GetMessageAsync(message.Id) as IUserMessage;
                        var embed = teamMsg.Embeds.Single();

                        var slot = team.Slots.Single(x => x.Emoji == reaction.Emote.ToString() || x.Emoji == reactionStringAnimatedVersion);
                        slot.Signed.Remove(user.Id);
                        mission.SignedUsers.Remove(user.Id);

                        var newDescription = _miscHelper.BuildTeamSlots(team);

                        var newEmbed = new EmbedBuilder
                        {
                            Title = team.Name,
                            Color = embed.Color
                        };

                        if (newDescription.Count == 2)
                            newEmbed.WithDescription(newDescription[0] + newDescription[1]);
                        else if (newDescription.Count == 1)
                            newEmbed.WithDescription(newDescription[0]);

                        if (embed.Footer.HasValue)
                            newEmbed.WithFooter(embed.Footer.Value.Text);
                        else
                            newEmbed.WithFooter(team.Pattern);

                        await teamMsg.ModifyAsync(x => x.Embed = newEmbed.Build());
                    }
                }
            }
            finally
            {
                mission.Access.Release();
            }
        }

        private async Task RemovedReactionInRolesChannel(Cacheable<IUserMessage, ulong> message, ISocketMessageChannel channel, SocketReaction reaction)
        {
            var fullMessage = await channel.GetMessageAsync(message.Id) as IUserMessage;

            var messageDescription = fullMessage.Embeds.Single().Description;
            ulong rank;
            var reactionsMatches = MiscHelper.GetRankArrayMatchesFromText(messageDescription);
            var rankForEmoji = reactionsMatches.Find(x => x.Item1 == reaction.Emote.ToString());

            try
            {
                string regexPattern = @"\<\@\&([0-9]+)\>";
                var rankMatches = Regex.Matches(rankForEmoji.Item2, regexPattern, RegexOptions.IgnoreCase | RegexOptions.RightToLeft).First().ToString();
                rank = ulong.Parse(Regex.Matches(rankMatches, "[0-9]+", RegexOptions.IgnoreCase | RegexOptions.RightToLeft).First().Value);
            }
            catch (Exception e)
            {
                Console.WriteLine($"Parsing ranks failed.");
                return;
            }

            try
            {
                var role = (channel as SocketGuildChannel).Guild.GetRole(rank);

                await (reaction.User.Value as SocketGuildUser).RemoveRoleAsync(role);

            }
            catch (Exception ex)
            {
                Console.WriteLine($"Adding rank failed.");
            }

            return;
        }

    }
}