// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Collections;
using System.Collections.Concurrent;
using Microsoft.AspNetCore.Connections;
 
namespace SignalRSamples;
 
internal class ConnectionList : IReadOnlyCollection<ConnectionContext>
{
    private readonly ConcurrentDictionary<string, ConnectionContext> _connections = new ConcurrentDictionary<string, ConnectionContext>(StringComparer.Ordinal);
 
    public ConnectionContext this[string connectionId]
    {
        get
        {
            if (_connections.TryGetValue(connectionId, out var connection))
            {
                return connection;
            }
            return null;
        }
    }
 
    public int Count => _connections.Count;
 
    public void Add(ConnectionContext connection)
    {
        _connections.TryAdd(connection.ConnectionId, connection);
    }
 
    public void Remove(ConnectionContext connection)
    {
        _connections.TryRemove(connection.ConnectionId, out var dummy);
    }
 
    public IEnumerator<ConnectionContext> GetEnumerator()
    {
        foreach (var item in _connections)
        {
            yield return item.Value;
        }
    }
 
    IEnumerator IEnumerable.GetEnumerator()
    {
        return GetEnumerator();
    }
}