1 files changed, 202 insertions, 0 deletions
diff --git a/Emby.Dlna/Eventing/DlnaEventManager.cs b/Emby.Dlna/Eventing/DlnaEventManager.cs
new file mode 100644
index 000000000..b66e966df
--- /dev/null
+++ b/Emby.Dlna/Eventing/DlnaEventManager.cs
@@ -0,0 +1,202 @@
+#pragma warning disable CS1591
+
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Net.Http;
+using System.Text;
+using System.Threading.Tasks;
+using MediaBrowser.Common.Extensions;
+using MediaBrowser.Common.Net;
+using Microsoft.Extensions.Logging;
+
+namespace Emby.Dlna.Eventing
+{
+    public class DlnaEventManager : IDlnaEventManager
+    {
+        private readonly ConcurrentDictionary<string, EventSubscription> _subscriptions =
+            new ConcurrentDictionary<string, EventSubscription>(StringComparer.OrdinalIgnoreCase);
+
+        private readonly ILogger _logger;
+        private readonly IHttpClient _httpClient;
+
+        private readonly CultureInfo _usCulture = new CultureInfo("en-US");
+
+        public DlnaEventManager(ILogger logger, IHttpClient httpClient)
+        {
+            _httpClient = httpClient;
+            _logger = logger;
+        }
+
+        public EventSubscriptionResponse RenewEventSubscription(string subscriptionId, string notificationType, string requestedTimeoutString, string callbackUrl)
+        {
+            var subscription = GetSubscription(subscriptionId, false);
+            if (subscription != null)
+            {
+                subscription.TimeoutSeconds = ParseTimeout(requestedTimeoutString) ?? 300;
+                int timeoutSeconds = subscription.TimeoutSeconds;
+                subscription.SubscriptionTime = DateTime.UtcNow;
+
+                _logger.LogDebug(
+                    "Renewing event subscription for {0} with timeout of {1} to {2}",
+                    subscription.NotificationType,
+                    timeoutSeconds,
+                    subscription.CallbackUrl);
+
+                return GetEventSubscriptionResponse(subscriptionId, requestedTimeoutString, timeoutSeconds);
+            }
+
+            return new EventSubscriptionResponse
+            {
+                Content = string.Empty,
+                ContentType = "text/plain"
+            };
+        }
+
+        public EventSubscriptionResponse CreateEventSubscription(string notificationType, string requestedTimeoutString, string callbackUrl)
+        {
+            var timeout = ParseTimeout(requestedTimeoutString) ?? 300;
+            var id = "uuid:" + Guid.NewGuid().ToString("N", CultureInfo.InvariantCulture);
+
+            _logger.LogDebug(
+                "Creating event subscription for {0} with timeout of {1} to {2}",
+                notificationType,
+                timeout,
+                callbackUrl);
+
+            _subscriptions.TryAdd(id, new EventSubscription
+            {
+                Id = id,
+                CallbackUrl = callbackUrl,
+                SubscriptionTime = DateTime.UtcNow,
+                TimeoutSeconds = timeout
+            });
+
+            return GetEventSubscriptionResponse(id, requestedTimeoutString, timeout);
+        }
+
+        private int? ParseTimeout(string header)
+        {
+            if (!string.IsNullOrEmpty(header))
+            {
+                // Starts with SECOND-
+                header = header.Split('-').Last();
+
+                if (int.TryParse(header, NumberStyles.Integer, _usCulture, out var val))
+                {
+                    return val;
+                }
+            }
+
+            return null;
+        }
+
+        public EventSubscriptionResponse CancelEventSubscription(string subscriptionId)
+        {
+            _logger.LogDebug("Cancelling event subscription {0}", subscriptionId);
+
+            _subscriptions.TryRemove(subscriptionId, out _);
+
+            return new EventSubscriptionResponse
+            {
+                Content = string.Empty,
+                ContentType = "text/plain"
+            };
+        }
+
+        private EventSubscriptionResponse GetEventSubscriptionResponse(string subscriptionId, string requestedTimeoutString, int timeoutSeconds)
+        {
+            var response = new EventSubscriptionResponse
+            {
+                Content = string.Empty,
+                ContentType = "text/plain"
+            };
+
+            response.Headers["SID"] = subscriptionId;
+            response.Headers["TIMEOUT"] = string.IsNullOrEmpty(requestedTimeoutString) ? ("SECOND-" + timeoutSeconds.ToString(_usCulture)) : requestedTimeoutString;
+
+            return response;
+        }
+
+        public EventSubscription GetSubscription(string id)
+        {
+            return GetSubscription(id, false);
+        }
+
+        private EventSubscription GetSubscription(string id, bool throwOnMissing)
+        {
+            if (!_subscriptions.TryGetValue(id, out EventSubscription e) && throwOnMissing)
+            {
+                throw new ResourceNotFoundException("Event with Id " + id + " not found.");
+            }
+
+            return e;
+        }
+
+        public Task TriggerEvent(string notificationType, IDictionary<string, string> stateVariables)
+        {
+            var subs = _subscriptions.Values
+                .Where(i => !i.IsExpired && string.Equals(notificationType, i.NotificationType, StringComparison.OrdinalIgnoreCase))
+                .ToList();
+
+            var tasks = subs.Select(i => TriggerEvent(i, stateVariables));
+
+            return Task.WhenAll(tasks);
+        }
+
+        private async Task TriggerEvent(EventSubscription subscription, IDictionary<string, string> stateVariables)
+        {
+            var builder = new StringBuilder();
+
+            builder.Append("<?xml version=\"1.0\"?>");
+            builder.Append("<e:propertyset xmlns:e=\"urn:schemas-upnp-org:event-1-0\">");
+            foreach (var key in stateVariables.Keys)
+            {
+                builder.Append("<e:property>")
+                    .Append('<')
+                    .Append(key)
+                    .Append('>')
+                    .Append(stateVariables[key])
+                    .Append("</")
+                    .Append(key)
+                    .Append('>')
+                    .Append("</e:property>");
+            }
+
+            builder.Append("</e:propertyset>");
+
+            var options = new HttpRequestOptions
+            {
+                RequestContent = builder.ToString(),
+                RequestContentType = "text/xml",
+                Url = subscription.CallbackUrl,
+                BufferContent = false
+            };
+
+            options.RequestHeaders.Add("NT", subscription.NotificationType);
+            options.RequestHeaders.Add("NTS", "upnp:propchange");
+            options.RequestHeaders.Add("SID", subscription.Id);
+            options.RequestHeaders.Add("SEQ", subscription.TriggerCount.ToString(_usCulture));
+
+            try
+            {
+                using (await _httpClient.SendAsync(options, new HttpMethod("NOTIFY")).ConfigureAwait(false))
+                {
+                }
+            }
+            catch (OperationCanceledException)
+            {
+            }
+            catch
+            {
+                // Already logged at lower levels
+            }
+            finally
+            {
+                subscription.IncrementTriggerCount();
+            }
+        }
+    }
+}