#nullable disable
#pragma warning disable CS1591, SA1306, SA1401
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Net.WebSockets;
using System.Threading;
using System.Threading.Tasks;
using MediaBrowser.Controller.Net.WebSocketMessages;
using MediaBrowser.Model.Session;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
namespace MediaBrowser.Controller.Net
{
///
/// Starts sending data over a web socket periodically when a message is received, and then stops when a corresponding stop message is received.
///
/// The type of the T return data type.
/// The type of the T state type.
public abstract class BasePeriodicWebSocketListener : IWebSocketListener, IDisposable
where TStateType : WebSocketListenerState, new()
where TReturnDataType : class
{
///
/// The _active connections.
///
private readonly List> _activeConnections =
new List>();
///
/// The logger.
///
protected ILogger> Logger;
protected BasePeriodicWebSocketListener(ILogger> logger)
{
ArgumentNullException.ThrowIfNull(logger);
Logger = logger;
}
///
/// Gets the type used for the messages sent to the client.
///
/// The type.
protected abstract SessionMessageType Type { get; }
///
/// Gets the message type received from the client to start sending messages.
///
/// The type.
protected abstract SessionMessageType StartType { get; }
///
/// Gets the message type received from the client to stop sending messages.
///
/// The type.
protected abstract SessionMessageType StopType { get; }
///
/// Gets the data to send.
///
/// Task{`1}.
protected abstract Task GetDataToSend();
///
/// Processes the message.
///
/// The message.
/// Task.
public Task ProcessMessageAsync(WebSocketMessageInfo message)
{
ArgumentNullException.ThrowIfNull(message);
if (message.MessageType == StartType)
{
Start(message);
}
if (message.MessageType == StopType)
{
Stop(message);
}
return Task.CompletedTask;
}
///
public Task ProcessWebSocketConnectedAsync(IWebSocketConnection connection, HttpContext httpContext) => Task.CompletedTask;
///
/// Starts sending messages over a web socket.
///
/// The message.
private void Start(WebSocketMessageInfo message)
{
var vals = message.Data.Split(',');
var dueTimeMs = long.Parse(vals[0], CultureInfo.InvariantCulture);
var periodMs = long.Parse(vals[1], CultureInfo.InvariantCulture);
var cancellationTokenSource = new CancellationTokenSource();
Logger.LogDebug("WS {1} begin transmitting to {0}", message.Connection.RemoteEndPoint, GetType().Name);
var state = new TStateType
{
IntervalMs = periodMs,
InitialDelayMs = dueTimeMs
};
lock (_activeConnections)
{
_activeConnections.Add(new Tuple(message.Connection, cancellationTokenSource, state));
}
}
protected async Task SendData(bool force)
{
Tuple[] tuples;
lock (_activeConnections)
{
tuples = _activeConnections
.Where(c =>
{
if (c.Item1.State == WebSocketState.Open && !c.Item2.IsCancellationRequested)
{
var state = c.Item3;
if (force || (DateTime.UtcNow - state.DateLastSendUtc).TotalMilliseconds >= state.IntervalMs)
{
return true;
}
}
return false;
})
.ToArray();
}
IEnumerable GetTasks()
{
foreach (var tuple in tuples)
{
yield return SendData(tuple);
}
}
await Task.WhenAll(GetTasks()).ConfigureAwait(false);
}
private async Task SendData(Tuple tuple)
{
var connection = tuple.Item1;
try
{
var state = tuple.Item3;
var cancellationToken = tuple.Item2.Token;
var data = await GetDataToSend().ConfigureAwait(false);
if (data is not null)
{
await connection.SendAsync(
new OutboundWebSocketMessage
{
MessageId = Guid.NewGuid(),
MessageType = Type,
Data = data
},
cancellationToken).ConfigureAwait(false);
state.DateLastSendUtc = DateTime.UtcNow;
}
}
catch (OperationCanceledException)
{
if (tuple.Item2.IsCancellationRequested)
{
DisposeConnection(tuple);
}
}
catch (Exception ex)
{
Logger.LogError(ex, "Error sending web socket message {Name}", Type);
DisposeConnection(tuple);
}
}
///
/// Stops sending messages over a web socket.
///
/// The message.
private void Stop(WebSocketMessageInfo message)
{
lock (_activeConnections)
{
var connection = _activeConnections.FirstOrDefault(c => c.Item1 == message.Connection);
if (connection is not null)
{
DisposeConnection(connection);
}
}
}
///
/// Disposes the connection.
///
/// The connection.
private void DisposeConnection(Tuple connection)
{
Logger.LogDebug("WS {1} stop transmitting to {0}", connection.Item1.RemoteEndPoint, GetType().Name);
// TODO disposing the connection seems to break websockets in subtle ways, so what is the purpose of this function really...
// connection.Item1.Dispose();
try
{
connection.Item2.Cancel();
connection.Item2.Dispose();
}
catch (ObjectDisposedException ex)
{
// TODO Investigate and properly fix.
Logger.LogError(ex, "Object Disposed");
}
catch (Exception ex)
{
// TODO Investigate and properly fix.
Logger.LogError(ex, "Error disposing websocket");
}
lock (_activeConnections)
{
_activeConnections.Remove(connection);
}
}
///
/// Releases unmanaged and - optionally - managed resources.
///
/// true to release both managed and unmanaged resources; false to release only unmanaged resources.
protected virtual void Dispose(bool dispose)
{
if (dispose)
{
lock (_activeConnections)
{
foreach (var connection in _activeConnections.ToArray())
{
DisposeConnection(connection);
}
}
}
}
///
/// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
///
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
}
}