using Discord.Interactions; using NodaTime; using System.Collections.ObjectModel; using System.Globalization; using System.Text; namespace WorldTime; public class ApplicationCommands : InteractionModuleBase { const string ErrNotAllowed = ":x: Only server moderators may use this command."; const string EmbedHelpField1 = $"`/help` - {HelpHelp}\n" + $"`/list` - {HelpList}\n" + $"`/set` - {HelpSet}\n" + $"`/remove` - {HelpRemove}"; const string EmbedHelpField2 = $"`/set-for` - {HelpSetFor}\n`/remove-for` - {HelpRemoveFor}"; #region Help strings const string HelpHelp = "Displays a list of available bot commands."; const string HelpList = "Shows the current time for all recently active known users."; const string HelpSet = "Adds or updates your time zone to the bot."; const string HelpSetFor = "Sets/updates time zone for a given user."; const string HelpRemove = "Removes your time zone information from this bot."; const string HelpRemoveFor = "Removes time zone for a given user."; #endregion private const string ErrInvalidZone = ":x: Not a valid zone name." + " To find your time zone, refer to: ."; private const string ErrNoUserCache = ":warning: Please try the command again."; private static readonly ReadOnlyDictionary _tzNameMap; public DiscordShardedClient ShardedClient { get; set; } = null!; public Database Database { get; set; } = null!; static ApplicationCommands() { Dictionary tzNameMap = new(StringComparer.OrdinalIgnoreCase); foreach (var name in DateTimeZoneProviders.Tzdb.Ids) tzNameMap.Add(name, name); _tzNameMap = new(tzNameMap); } [SlashCommand("help", HelpHelp)] public async Task CmdHelp() { var version = System.Reflection.Assembly.GetExecutingAssembly().GetName().Version!.ToString(3); var guildct = ShardedClient.Guilds.Count; var uniquetz = await Database.GetDistinctZoneCountAsync(); await RespondAsync(embed: new EmbedBuilder() { Title = "Help & About", Description = $"World Time v{version} - Serving {guildct} communities across {uniquetz} time zones.\n\n" + "This bot is provided for free, without any paywalled 'premium' features. " + "If you've found this bot useful, please consider contributing via the " + "bot author's page on Ko-fi: https://ko-fi.com/noithecat.", Footer = new EmbedFooterBuilder() { IconUrl = Context.Client.CurrentUser.GetAvatarUrl(), Text = "World Time" } }.AddField(inline: false, name: "Commands", value: EmbedHelpField1 ).AddField(inline: false, name: "Admin commands", value: EmbedHelpField2 ).AddField(inline: false, name: "Zones", value: "This bot accepts zone names from the IANA Time Zone Database (a.k.a. Olson Database). " + "A useful tool to determine yours can be found at: https://kevinnovak.github.io/Time-Zone-Picker/" ).Build()); } [RequireGuildContext] [SlashCommand("list", HelpList)] public async Task CmdList([Summary(description: "A specific user whose time to look up.")]SocketGuildUser? user = null) { if (!await AreUsersDownloadedAsync(Context.Guild)) { await RespondAsync(ErrNoUserCache, ephemeral: true); return; } if (user != null) { await CmdListUserAsync(user); return; } var userlist = await Database.GetGuildZonesAsync(Context.Guild.Id); if (userlist.Count == 0) { await RespondAsync(":x: Nothing to show. Register your time zones with the bot using the `/set` command."); return; } // Order times by popularity to limit how many are shown, group by printed name var sortedlist = new SortedDictionary>(); foreach ((string area, List users) in userlist.OrderByDescending(o => o.Value.Count).Take(20)) { // Filter further to top 20 distinct timezones, even if they are not displayed in the final result var areaprint = TzPrint(area); if (!sortedlist.ContainsKey(areaprint)) sortedlist.Add(areaprint, new List()); sortedlist[areaprint].AddRange(users); } const int MaxSingleLineLength = 750; const int MaxSingleOutputLength = 900; // Build zone listings with users var outputlines = new List(); foreach ((string area, List users) in sortedlist) { var buffer = new StringBuilder(); buffer.Append(area[4..] + ": "); bool empty = true; foreach (var userid in users) { var userinstance = Context.Guild.GetUser(userid); if (userinstance == null) continue; if (empty) empty = !empty; else buffer.Append(", "); var useradd = FormatName(userinstance); if (buffer.Length + useradd.Length > MaxSingleLineLength) { buffer.Append("others..."); break; } else buffer.Append(useradd); } if (!empty) outputlines.Add(buffer.ToString()); } // Prepare for output - send buffers out if they become too large outputlines.Sort(); bool hasOutputOneLine = false; // First output is shown as an interaction response, followed then as regular channel messages async Task doOutput(Embed msg) { if (!hasOutputOneLine) { await RespondAsync(embed: msg); hasOutputOneLine = true; } else { await ReplyAsync(embed: msg); } } var resultout = new StringBuilder(); foreach (var line in outputlines) { if (resultout.Length + line.Length > MaxSingleOutputLength) { await doOutput(new EmbedBuilder().WithDescription(resultout.ToString()).Build()); resultout.Clear(); } if (resultout.Length > 0) resultout.AppendLine(); // avoids trailing newline by adding to the previous line resultout.Append(line); } if (resultout.Length > 0) { await doOutput(new EmbedBuilder().WithDescription(resultout.ToString()).Build()); } } private async Task CmdListUserAsync(SocketGuildUser parameter) { // Not meant as a command handler - called by CmdList var result = await Database.GetUserZoneAsync(parameter); if (result == null) { bool isself = Context.User.Id == parameter.Id; if (isself) await RespondAsync(":x: You do not have a time zone. Set it with `tz.set`.", ephemeral: true); else await RespondAsync(":x: The given user does not have a time zone set.", ephemeral: true); return; } var resulttext = TzPrint(result)[4..] + ": " + FormatName(parameter); await RespondAsync(embed: new EmbedBuilder().WithDescription(resulttext).Build()); } [SlashCommand("set", HelpSet)] public async Task CmdSet([Summary(description: "The new time zone to set.")]string zone) { var parsedzone = ParseTimeZone(zone); if (parsedzone == null) { await RespondAsync(ErrInvalidZone, ephemeral: true); return; } await Database.UpdateUserAsync((SocketGuildUser)Context.User, parsedzone); await RespondAsync($":white_check_mark: Your time zone has been set to **{parsedzone}**."); } [RequireGuildContext] [SlashCommand("set-for", HelpSetFor)] public async Task CmdSetFor([Summary(description: "The user whose time zone to modify.")] SocketGuildUser user, [Summary(description: "The new time zone to set.")] string zone) { if (!IsUserAdmin((SocketGuildUser)Context.User)) { await RespondAsync(ErrNotAllowed, ephemeral: true).ConfigureAwait(false); return; } // Extract parameters var newtz = ParseTimeZone(zone); if (newtz == null) { await RespondAsync(ErrInvalidZone); return; } await Database.UpdateUserAsync(user, newtz).ConfigureAwait(false); await RespondAsync($":white_check_mark: Time zone for **{user}** set to **{newtz}**."); } [RequireGuildContext] [SlashCommand("remove", HelpRemove)] public async Task CmdRemove() { var success = await Database.DeleteUserAsync((SocketGuildUser)Context.User); if (success) await RespondAsync(":white_check_mark: Your zone has been removed."); else await RespondAsync(":x: You don't have a time zone set."); } [RequireGuildContext] [SlashCommand("remove-for", HelpRemoveFor)] public async Task CmdRemoveFor([Summary(description: "The user whose time zone to remove.")] SocketGuildUser user) { if (!IsUserAdmin((SocketGuildUser)Context.User)) { await RespondAsync(ErrNotAllowed, ephemeral: true).ConfigureAwait(false); return; } if (await Database.DeleteUserAsync(user)) await RespondAsync($":white_check_mark: Removed zone information for {user}."); else await RespondAsync($":white_check_mark: No time zone is set for {user}."); } #region Helper methods /// /// Returns a string displaying the current time in the given time zone. /// The result begins with four numbers for sorting purposes. Must be trimmed before output. /// private static string TzPrint(string zone) { var tzdb = DateTimeZoneProviders.Tzdb; DateTimeZone tz = tzdb.GetZoneOrNull(zone)!; if (tz == null) throw new Exception("Encountered unknown time zone: " + zone); var now = SystemClock.Instance.GetCurrentInstant().InZone(tz); var sortpfx = now.ToString("MMdd", DateTimeFormatInfo.InvariantInfo); var fullstr = now.ToString("dd'-'MMM' 'HH':'mm' 'x' (UTC'o')'", DateTimeFormatInfo.InvariantInfo); return $"{sortpfx}● `{fullstr}`"; } /// /// Checks given time zone input. Returns a valid string for use with NodaTime, or null. /// private static string? ParseTimeZone(string tzinput) { if (tzinput.Equals("Asia/Calcutta", StringComparison.OrdinalIgnoreCase)) tzinput = "Asia/Kolkata"; if (_tzNameMap.TryGetValue(tzinput, out var name)) return name; return null; } /// /// Formats a user's name to a consistent, readable format which makes use of their nickname. /// private static string FormatName(SocketGuildUser user) { static string escapeFormattingCharacters(string input) { var result = new StringBuilder(); foreach (var c in input) { if (c is '\\' or '_' or '~' or '*' or '@') { result.Append('\\'); } result.Append(c); } return result.ToString(); } var username = escapeFormattingCharacters(user.Username); if (user.Nickname != null) { return $"**{escapeFormattingCharacters(user.Nickname)}** ({username}#{user.Discriminator})"; } return $"**{username}**#{user.Discriminator}"; } /// /// Checks if the given user can be considered a guild admin ('Manage Server' is set). /// // TODO replace this with a precondition, or there's also a new permission scheme going around? private static bool IsUserAdmin(SocketGuildUser user) => user.GuildPermissions.Administrator || user.GuildPermissions.ManageGuild; /// /// Checks if the member cache for the specified guild needs to be filled, and sends a request if needed. /// /// /// Due to a quirk in Discord.Net, the user cache cannot be filled until the command handler is no longer executing /// regardless of if the request runs on its own thread, thus requiring the user to run the command again. /// /// /// True if the guild's members are already downloaded. If false, the command handler must notify the user. /// private static async Task AreUsersDownloadedAsync(SocketGuild guild) { static bool HasMostMembersDownloaded(SocketGuild guild) { if (guild.HasAllMembers) return true; if (guild.MemberCount > 30) { // For guilds of size over 30, require 85% or more of the members to be known // (26/30, 42/50, 255/300, etc) return guild.DownloadedMemberCount >= (int)(guild.MemberCount * 0.85); } else { // For smaller guilds, fail if two or more members are missing return guild.MemberCount - guild.DownloadedMemberCount <= 2; } } if (HasMostMembersDownloaded(guild)) return true; else { // Event handler hangs if awaited normally or used with Task.Run await Task.Factory.StartNew(guild.DownloadUsersAsync).ConfigureAwait(false); return false; } } #endregion }