SupportChild/Commands/MoveCommand.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using DSharpPlus.Entities;
using DSharpPlus.Exceptions;
using DSharpPlus.SlashCommands;
using DSharpPlus.SlashCommands.Attributes;

namespace SupportChild.Commands;

public class MoveCommand : ApplicationCommandModule
{
	[SlashRequireGuild]
	[SlashCommand("move", "Moves a ticket to another category.")]
	public async Task OnExecute(InteractionContext command, [Option("Category", "The category to move the ticket to. Only has to be the beginning of the name.")] string category)
	{
		// Check if ticket exists in the database
		if (!Database.TryGetOpenTicket(command.Channel.Id, out Database.Ticket _))
		{
			await command.CreateResponseAsync(new DiscordEmbedBuilder
			{
				Color = DiscordColor.Red,
				Description = "This channel is not a ticket."
			}, true);
			return;
		}

		if (string.IsNullOrEmpty(category))
		{
			await command.CreateResponseAsync(new DiscordEmbedBuilder
			{
				Color = DiscordColor.Red,
				Description = "Error: No category provided."
			}, true);
			return;
		}

		IReadOnlyList<DiscordChannel> channels = await command.Guild.GetChannelsAsync();
		IEnumerable<DiscordChannel> categories = channels.Where(x => x.IsCategory);
		DiscordChannel categoryChannel = categories.FirstOrDefault(x => x.Name.StartsWith(category.Trim(), StringComparison.OrdinalIgnoreCase));

		if (categoryChannel == null)
		{
			await command.CreateResponseAsync(new DiscordEmbedBuilder
			{
				Color = DiscordColor.Red,
				Description = "Error: Could not find a category by that name."
			}, true);
			return;
		}

		if (command.Channel.Id == categoryChannel.Id)
		{
			await command.CreateResponseAsync(new DiscordEmbedBuilder
			{
				Color = DiscordColor.Red,
				Description = "Error: The ticket is already in that category."
			}, true);
			return;
		}

		try
		{
			await command.Channel.ModifyAsync(modifiedAttributes => modifiedAttributes.Parent = categoryChannel);
		}
		catch (UnauthorizedException)
		{
			await command.CreateResponseAsync(new DiscordEmbedBuilder
			{
				Color = DiscordColor.Red,
				Description = "Error: Not authorized to move this ticket to that category."
			}, true);
			return;
		}

		await command.CreateResponseAsync(new DiscordEmbedBuilder
		{
			Color = DiscordColor.Green,
			Description = "Ticket was moved to " + categoryChannel.Mention
		});
	}
}