using System; using System.Threading.Tasks; using App.Metrics; using Discord; using Discord.WebSocket; using Microsoft.Extensions.DependencyInjection; namespace PluralKit.Bot.CommandSystem { public class Context { private IServiceProvider _provider; private readonly DiscordShardedClient _client; private readonly SocketUserMessage _message; private readonly Parameters _parameters; private readonly IDataStore _data; private readonly PKSystem _senderSystem; private readonly IMetrics _metrics; private Command _currentCommand; public Context(IServiceProvider provider, SocketUserMessage message, int commandParseOffset, PKSystem senderSystem) { _client = provider.GetRequiredService() as DiscordShardedClient; _message = message; _data = provider.GetRequiredService(); _senderSystem = senderSystem; _metrics = provider.GetRequiredService(); _provider = provider; _parameters = new Parameters(message.Content.Substring(commandParseOffset)); } public IUser Author => _message.Author; public IMessageChannel Channel => _message.Channel; public IUserMessage Message => _message; public IGuild Guild => (_message.Channel as ITextChannel)?.Guild; public DiscordSocketClient Shard => _client.GetShardFor(Guild); public DiscordShardedClient Client => _client; public PKSystem System => _senderSystem; public string PopArgument() => _parameters.Pop(); public string PeekArgument() => _parameters.Peek(); public string Remainder() => _parameters.Remainder(); public string RemainderOrNull() => Remainder().Trim().Length == 0 ? null : Remainder(); public bool HasNext() => RemainderOrNull() != null; public string FullCommand => _parameters.FullCommand; public Task Reply(string text = null, Embed embed = null) => Channel.SendMessageAsync(text, embed: embed); /// /// Checks if the next parameter is equal to one of the given keywords. Case-insensitive. /// public bool Match(params string[] potentialMatches) { foreach (var match in potentialMatches) { if (PeekArgument().Equals(match, StringComparison.InvariantCultureIgnoreCase)) { PopArgument(); return true; } } return false; } public async Task Execute(Command commandDef, Func handler) { _currentCommand = commandDef; try { await handler(_provider.GetRequiredService()); _metrics.Measure.Meter.Mark(BotMetrics.CommandsRun); } catch (PKSyntaxError e) { await Reply($"{Emojis.Error} {e.Message}\n**Command usage:**\n> pk;{commandDef.Usage}"); } catch (PKError e) { await Reply($"{Emojis.Error} {e.Message}"); } catch (TimeoutException) { // Got a complaint the old error was a bit too patronizing. Hopefully this is better? await Reply($"{Emojis.Error} Operation timed out, sorry. Try again, perhaps?"); } } public async Task MatchUser() { var text = PeekArgument(); if (MentionUtils.TryParseUser(text, out var id)) return await Shard.Rest.GetUserAsync(id); // TODO: this should properly fetch return null; } public Task PeekSystem() => MatchSystemInner(); public async Task MatchSystem() { var system = await MatchSystemInner(); if (system != null) PopArgument(); return system; } private async Task MatchSystemInner() { var input = PeekArgument(); // System references can take three forms: // - The direct user ID of an account connected to the system // - A @mention of an account connected to the system (<@uid>) // - A system hid // Direct IDs and mentions are both handled by the below method: if (input.TryParseMention(out var id)) return await _data.GetSystemByAccount(id); // Finally, try HID parsing var system = await _data.GetSystemByHid(input); return system; } public async Task PeekMember() { var input = PeekArgument(); // Member references can have one or two forms, depending on // whether you're in a system or not: // - A member hid // - A textual name of a member *in your own system* // First, if we have a system, try finding by member name in system if (_senderSystem != null && await _data.GetMemberByName(_senderSystem, input) is PKMember memberByName) return memberByName; // Then, try member HID parsing: if (await _data.GetMemberByHid(input) is PKMember memberByHid) return memberByHid; // We didn't find anything, so we return null. return null; } /// /// Attempts to pop a member descriptor from the stack, returning it if present. If a member could not be /// resolved by the next word in the argument stack, does *not* touch the stack, and returns null. /// public async Task MatchMember() { // First, peek a member var member = await PeekMember(); // If the peek was successful, we've used up the next argument, so we pop that just to get rid of it. if (member != null) PopArgument(); // Finally, we return the member value. return member; } public string CreateMemberNotFoundError(string input) { // TODO: does this belong here? if (input.Length == 5) { if (_senderSystem != null) return $"Member with ID or name \"{input.SanitizeMentions()}\" not found."; return $"Member with ID \"{input.SanitizeMentions()}\" not found."; // Accounts without systems can't query by name } if (_senderSystem != null) return $"Member with name \"{input.SanitizeMentions()}\" not found. Note that a member ID is 5 characters long."; return $"Member not found. Note that a member ID is 5 characters long."; } public Context CheckSystem() { if (_senderSystem == null) throw Errors.NoSystemError; return this; } public Context CheckNoSystem() { if (_senderSystem != null) throw Errors.ExistingSystemError; return this; } public Context CheckOwnMember(PKMember member) { if (member.System != _senderSystem.Id) throw Errors.NotOwnMemberError; return this; } public GuildPermissions GetGuildPermissions(IUser user) { if (Channel is SocketGuildChannel gc) return gc.GetUser(user.Id).GuildPermissions; return GuildPermissions.None; } public ChannelPermissions GetChannelPermissions(IUser user) { if (Channel is SocketGuildChannel gc) return gc.GetUser(user.Id).GetPermissions(gc); return ChannelPermissions.DM; } public Context CheckAuthorPermission(GuildPermission permission, string permissionName) { if (!GetGuildPermissions(Author).Has(permission)) throw new PKError($"You must have the \"{permissionName}\" permission in this server to use this command."); return this; } public Context CheckAuthorPermission(ChannelPermission permission, string permissionName) { if (!GetChannelPermissions(Author).Has(permission)) throw new PKError($"You must have the \"{permissionName}\" permission in this server to use this command."); return this; } public Context CheckGuildContext() { if (Channel is IGuildChannel) return this; throw new PKError("This command can not be run in a DM."); } public ITextChannel MatchChannel() { if (!MentionUtils.TryParseChannel(PeekArgument(), out var channel)) return null; if (!(_client.GetChannel(channel) is ITextChannel textChannel)) return null; PopArgument(); return textChannel; } } }