using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using DSharpPlus.Entities;

namespace SupportChild;

public static class Utilities
{
	private static readonly Random rng = new Random();

	public static void Shuffle<T>(this IList<T> list)
	{
		int n = list.Count;
		while (n > 1)
		{
			n--;
			int k = rng.Next(n + 1);
			(list[k], list[n]) = (list[n], list[k]);
		}
	}

	public static LinkedList<string> ParseListIntoMessages(List<string> listItems)
	{
		LinkedList<string> messages = new LinkedList<string>();

		foreach (string listItem in listItems)
		{
			if (messages.Last?.Value?.Length + listItem?.Length < 2048)
			{
				messages.Last.Value += listItem;
			}
			else
			{
				messages.AddLast(listItem);
			}
		}

		return messages;
	}

	public static async Task<List<Database.Category>> GetVerifiedChannels()
	{
		List<Database.Category> verifiedCategories = new List<Database.Category>();
		foreach (Database.Category category in Database.GetAllCategories())
		{
			DiscordChannel channel = null;
			try
			{
				channel = await SupportChild.discordClient.GetChannelAsync(category.id);
			}
			catch (Exception) { /*ignored*/ }

			if (channel != null)
			{
				verifiedCategories.Add(category);
			}
			else
			{
				Logger.Warn("Category '" + category.name + "' (" + category.id + ") no longer exists! Ignoring...");
			}
		}
		return verifiedCategories;
	}
}