Octobot/src/Commands/RemindCommandGroup.cs

using System.ComponentModel;
using Boyfriend.Data;
using Boyfriend.Services;
using JetBrains.Annotations;
using Remora.Commands.Attributes;
using Remora.Commands.Groups;
using Remora.Discord.API.Abstractions.Objects;
using Remora.Discord.API.Abstractions.Rest;
using Remora.Discord.Commands.Attributes;
using Remora.Discord.Commands.Conditions;
using Remora.Discord.Commands.Contexts;
using Remora.Discord.Commands.Feedback.Services;
using Remora.Discord.Extensions.Embeds;
using Remora.Discord.Extensions.Formatting;
using Remora.Rest.Core;
using Remora.Results;

namespace Boyfriend.Commands;

/// <summary>
///     Handles the command to manage reminders: /remind
/// </summary>
[UsedImplicitly]
public class RemindCommandGroup : CommandGroup {
    private readonly ICommandContext     _context;
    private readonly GuildDataService    _dataService;
    private readonly FeedbackService     _feedbackService;
    private readonly IDiscordRestUserAPI _userApi;

    public RemindCommandGroup(
        ICommandContext     context, GuildDataService dataService, FeedbackService feedbackService,
        IDiscordRestUserAPI userApi) {
        _context = context;
        _dataService = dataService;
        _feedbackService = feedbackService;
        _userApi = userApi;
    }

    /// <summary>
    ///     A slash command that schedules a reminder with the specified text.
    /// </summary>
    /// <param name="in">The period of time which must pass before the reminder will be sent.</param>
    /// <param name="message">The text of the reminder.</param>
    /// <returns>A feedback sending result which may or may not have succeeded.</returns>
    [Command("remind")]
    [Description("Create a reminder")]
    [DiscordDefaultDMPermission(false)]
    [RequireContext(ChannelContext.Guild)]
    [UsedImplicitly]
    public async Task<Result> ExecuteReminderAsync(
        [Description("After what period of time mention the reminder")]
        TimeSpan @in,
        [Description("Reminder message")] string message) {
        if (!_context.TryGetContextIDs(out var guildId, out var channelId, out var userId))
            return Result.FromError(
                new ArgumentNullError(nameof(_context), "Unable to retrieve necessary IDs from command context"));

        var userResult = await _userApi.GetUserAsync(userId, CancellationToken);
        if (!userResult.IsDefined(out var user))
            return Result.FromError(userResult);

        var data = await _dataService.GetData(guildId, CancellationToken);
        Messages.Culture = GuildSettings.Language.Get(data.Settings);

        return await AddReminderAsync(@in, message, data, channelId, user, CancellationToken);
    }

    private async Task<Result> AddReminderAsync(
        TimeSpan  @in,       string message, GuildData         data,
        Snowflake channelId, IUser  user,    CancellationToken ct = default) {
        var remindAt = DateTimeOffset.UtcNow.Add(@in);

        data.GetMemberData(user.ID).Reminders.Add(
            new Reminder {
                At = remindAt,
                Channel = channelId.Value,
                Text = message
            });

        var embed = new EmbedBuilder().WithSmallTitle(string.Format(Messages.ReminderCreated, user.GetTag()), user)
            .WithDescription(string.Format(Messages.DescriptionReminderCreated, Markdown.Timestamp(remindAt)))
            .WithColour(ColorsList.Green)
            .Build();

        return await _feedbackService.SendContextualEmbedResultAsync(embed, ct);
    }
}