SupportChild/Commands/AddMessageCommand.cs

using DSharpPlus.Entities;
using System.Threading.Tasks;
using DSharpPlus.SlashCommands;
using DSharpPlus.SlashCommands.Attributes;

namespace SupportChild.Commands;

public class AddMessageCommand : ApplicationCommandModule
{
    [SlashRequireGuild]
    [SlashCommand("addmessage", "Adds a new message for the 'say' command.")]
    public async Task OnExecute(InteractionContext command,
        [Option("Identifier", "The identifier word used in the /say command.")] string identifier,
        [Option("Message", "The message the /say command will return.")] string message)
    {
        if (string.IsNullOrEmpty(message))
        {
            await command.CreateResponseAsync(new DiscordEmbedBuilder
            {
                Color = DiscordColor.Red,
                Description = "No message specified."
            }, true);
            return;
        }

        if (Database.TryGetMessage(identifier.ToLower(), out Database.Message _))
        {
            await command.CreateResponseAsync(new DiscordEmbedBuilder
            {
                Color = DiscordColor.Red,
                Description = "There is already a message with that identifier."
            }, true);
            return;
        }

        if (Database.AddMessage(identifier, command.Member.Id, message))
        {
            await command.CreateResponseAsync(new DiscordEmbedBuilder
            {
                Color = DiscordColor.Green,
                Description = "Message added."
            }, true);
        }
        else
        {
            await command.CreateResponseAsync(new DiscordEmbedBuilder
            {
                Color = DiscordColor.Red,
                Description = "Error: Failed adding the message to the database."
            }, true);
        }
    }
}