using System.Collections.Concurrent;
using System.Collections.Immutable;

namespace Connected.Net.Hubs;

public sealed class Clients<TArgs>
{
	public Clients()
	{
		Items = new(StringComparer.OrdinalIgnoreCase);
	}
	private ConcurrentDictionary<string, Client<TArgs>> Items { get; set; }
	public void AddOrUpdate(Client<TArgs> client)
	{
		if (!Items.TryGetValue(client.Connection, out Client<TArgs>? existing))
		{
			Items.TryAdd(client.Connection, client);
			return;
		}

		existing.RetentionDeadline = DateTime.MinValue;
	}

	public void Clean()
	{
		var dead = Items.Where(f => f.Value.RetentionDeadline != DateTime.MinValue && f.Value.RetentionDeadline <= DateTime.UtcNow).ToImmutableList();

		if (dead.IsEmpty)
			return;

		foreach (var client in dead)
			Items.TryRemove(client.Key, out _);
	}

	public void Remove(string connectionId)
	{
		if (!Items.TryGetValue(connectionId, out Client<TArgs>? client))
			return;

		if (client.Behavior == MessageClientBehavior.FireForget)
			Items.TryRemove(connectionId, out _);
		else
			client.RetentionDeadline = DateTime.UtcNow.AddMinutes(5);
	}

	public ImmutableList<Client<TArgs>> Query()
	{
		return Items.Values.ToImmutableList();
	}
}