public async Task Invoke(IDictionary <string, object> env)
{
var accept = env.TryGetValue("websocket.Accept", out var wsa) ? (WebSocketAccept)wsa : null;
if (accept != null && (_options.ConnectionEvaluator?.Invoke(env) ?? true))
{
env.TryGetValue("owin.RequestPath", out var oPath);
var path = (string)oPath;
var wsProtocolOpt = env.TryGetValue("owin.RequestHeaders", out var headers) ?
((IDictionary <string, string[]>)headers).TryGetValue("Sec-WebSocket-Protocol", out var secWsProtocol) ?
secWsProtocol?[0]?.Split(',')?.FirstOrDefault()?.Trim() : null : null;
Dictionary <string, object> acceptOptions = new Dictionary <string, object>();
if (wsProtocolOpt != null)
{
acceptOptions["websocket.SubProtocol"] = wsProtocolOpt;
}
var ctx = new OwinRequestContext(env);
accept(acceptOptions, (ws) => AcceptSocketAsync(ctx, ws));
env["owin.ResponseStatusCode"] = (int)HttpStatusCode.SwitchingProtocols;
}
else
{
await _next(env);
}
}
private async Task AcceptSocketAsync(OwinRequestContext ctx, IDictionary <string, object> ws)
{
if (!_options.ForceOwinWebsockets && ws.TryGetValue("System.Net.WebSockets.WebSocketContext", out var _wsctx))
{
WebSocketContext wsctx = (WebSocketContext)_wsctx;
await WebsocketConnector.HandleWebsocketAsync(ctx, wsctx.WebSocket, _options);
}
else
{
var wrapper = new OwinWebsocketWrapper(ws);
await WebsocketConnector.HandleWebsocketAsync(ctx, wrapper, _options);
}
}