feat(example): add handling of incoming call event

examples/WebApi/Controllers/HandleIncomingIceEventController.cs

@@ -0,0 +1,55 @@
+using Microsoft.AspNetCore.Mvc;
+using Sinch;
+using Sinch.Voice.Calls.Actions;
+using Sinch.Voice.Calls.Instructions;
+using Sinch.Voice.Hooks;
+
+namespace WebApiExamples.Controllers
+{
+    [ApiController]
+    [Route("voice")]
+    public class HandleIncomingIceEventController : ControllerBase
+    {
+        private readonly ISinchClient _sinchClient;
+
+        public HandleIncomingIceEventController(ISinchClient sinchClient)
+        {
+            _sinchClient = sinchClient;
+        }
+
+        [HttpPost]
+        [Route("event")]
+        public IActionResult HandleEvent([FromBody] IVoiceEvent incomingEvent)
+        {
+            switch (incomingEvent)
+            {
+                case AnsweredCallEvent answeredCallEvent:
+                    break;
+                case DisconnectedCallEvent disconnectedCallEvent:
+                    break;
+                case IncomingCallEvent incomingCallEvent:
+                    var response = new CallEventResponse()
+                    {
+                        Action = new Hangup(),
+                        Instructions = new List<IInstruction>()
+                        {
+                            new Say()
+                            {
+                                Text = "Thank you for calling Sinch! This call will now end.",
+                                Locale = "en-US"
+                            }
+                        }
+                    };
+                    return Ok(response);
+                case NotificationEvent notificationEvent:
+                    break;
+                case PromptInputEvent promptInputEvent:
+                    break;
+                default:
+                    return BadRequest();
+            }
+
+            return BadRequest();
+        }
+    }
+}

src/Sinch/Voice/Hooks/AnsweredCallEvent.cs

@@ -14,14 +14,13 @@ namespace Sinch.Voice.Hooks
     ///     enabled, the amd object will also be present on ACE callbacks.
     ///     Note: ACE Callbacks are not issued for InApp Calls (destination: username), only PSTN and SIP calls.
     /// </summary>
-    public class AnsweredCallEvent
+    public class AnsweredCallEvent : IVoiceEvent
     {
         /// <summary>
         ///     Must have the value ace.
         /// </summary>
         [JsonPropertyName("event")]
-        [JsonInclude]
-        public string? Event { get; private set; }
+        public EventType? Event { get; set; }
 
 
         /// <summary>
@@ -64,5 +63,7 @@ public class AnsweredCallEvent
         /// </summary>
         [JsonPropertyName("amd")]
         public Amd? Amd { get; set; }
+
+        public EventType? EventType { get; }
     }
 }

src/Sinch/Voice/Hooks/DisconnectedCallEvent.cs

@@ -12,13 +12,13 @@ namespace Sinch.Voice.Hooks
     ///     This event doesn't support instructions and only supports the
     ///     [hangup](https://developers.sinch.com/docs/voice/api-reference/svaml/actions/#hangup) action.
     /// </summary>
-    public class DisconnectedCallEvent
+    public class DisconnectedCallEvent : IVoiceEvent
     {
         /// <summary>
         ///     Must have the value &#x60;dice&#x60;.
         /// </summary>
         [JsonPropertyName("event")]
-        public string? Event { get; set; }
+        public EventType? Event { get; set; }
 
 
         /// <summary>

src/Sinch/Voice/Hooks/EventType.cs

@@ -0,0 +1,15 @@
+using System.Text.Json.Serialization;
+using Sinch.Core;
+
+namespace Sinch.Voice.Hooks
+{
+    [JsonConverter(typeof(EnumRecordJsonConverter<EventType>))]
+    public record EventType(string Value) : EnumRecord(Value)
+    {
+        public static readonly EventType AnsweredCallEvent = new EventType("ace");
+        public static readonly EventType DisconnectedCallEvent = new EventType("dice");
+        public static readonly EventType IncomingCallEvent = new EventType("ice");
+        public static readonly EventType NotificationEvent = new EventType("notify");
+        public static readonly EventType PromptInputEvent = new EventType("pie");
+    }
+}

src/Sinch/Voice/Hooks/IVoiceEvent.cs

@@ -0,0 +1,80 @@
+using System;
+using System.Linq;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Sinch.Core;
+
+namespace Sinch.Voice.Hooks
+{
+    /// <summary>
+    ///     Marker interface for event types of voice.
+    /// </summary>
+    [JsonConverter(typeof(InterfaceConverter<IVoiceEvent>))]
+    public interface IVoiceEvent
+    {
+        [JsonPropertyName("event")]
+        public EventType? Event { get; }
+    }
+
+    public class VoiceEventConverter : JsonConverter<IVoiceEvent>
+    {
+        public override IVoiceEvent? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        {
+            var elem = JsonElement.ParseValue(ref reader);
+            var descriptor = elem.EnumerateObject().FirstOrDefault(x => x.Name == "event");
+            var type = descriptor.Value.GetString();
+
+            if (type == EventType.NotificationEvent.Value)
+            {
+                return elem.Deserialize<NotificationEvent>(options);
+            }
+
+            if (type == EventType.IncomingCallEvent.Value)
+            {
+                return elem.Deserialize<IncomingCallEvent>(options);
+            }
+
+            if (type == EventType.DisconnectedCallEvent.Value)
+            {
+                return elem.Deserialize<DisconnectedCallEvent>(options);
+            }
+
+            if (type == EventType.AnsweredCallEvent.Value)
+            {
+                return elem.Deserialize<AnsweredCallEvent>(options);
+            }
+
+            if (type == EventType.PromptInputEvent.Value)
+            {
+                return elem.Deserialize<PromptInputEvent>(options);
+            }
+
+            throw new JsonException($"Failed to match verification method object, got {descriptor.Name}");
+        }
+
+        public override void Write(Utf8JsonWriter writer, IVoiceEvent value, JsonSerializerOptions options)
+        {
+            switch (value)
+            {
+                case AnsweredCallEvent answeredCallEvent:
+                    JsonSerializer.Serialize(writer, answeredCallEvent, options);
+                    break;
+                case DisconnectedCallEvent disconnectedCallEvent:
+                    JsonSerializer.Serialize(writer, disconnectedCallEvent, options);
+                    break;
+                case IncomingCallEvent incomingCallEvent:
+                    JsonSerializer.Serialize(writer, incomingCallEvent, options);
+                    break;
+                case NotificationEvent notificationEvent:
+                    JsonSerializer.Serialize(writer, notificationEvent, options);
+                    break;
+                case PromptInputEvent promptInputEvent:
+                    JsonSerializer.Serialize(writer, promptInputEvent, options);
+                    break;
+                default:
+                    throw new ArgumentOutOfRangeException(nameof(value),
+                        $"Cannot find a matching class for the interface {nameof(IVoiceEvent)}");
+            }
+        }
+    }
+}

src/Sinch/Voice/Hooks/IncomingCallEvent.cs

@@ -15,13 +15,13 @@ namespace Sinch.Voice.Hooks
     ///     If there is no response to the callback within the timeout period, an error message is played, and the call is
     ///     disconnected.
     /// </summary>
-    public class IncomingCallEvent
+    public class IncomingCallEvent : IVoiceEvent
     {
         /// <summary>
         ///     Must have the value ice.
         /// </summary>
         [JsonPropertyName("event")]
-        public string? Event { get; set; }
+        public EventType? Event { get; set; }
 
 
         /// <summary>

src/Sinch/Voice/Hooks/NotificationEvent.cs

@@ -7,13 +7,13 @@ namespace Sinch.Voice.Hooks
     ///     <br /><br />
     ///     If there is no response to the callback within the timeout period, the notification is discarded.
     /// </summary>
-    public class NotificationEvent
+    public class NotificationEvent : IVoiceEvent
     {
         /// <summary>
         ///     Must have the value notify.
         /// </summary>
         [JsonPropertyName("event")]
-        public string? Event { get; set; }
+        public EventType? Event { get; set; }
 
         /// <summary>
         ///     The unique ID assigned to this call.

src/Sinch/Voice/Hooks/PromtInputEvent.cs

@@ -13,13 +13,13 @@ namespace Sinch.Voice.Hooks
     ///     [SVAML](https://developers.sinch.com/docs/voice/api-reference/svaml/) logic.<br /><br />
     ///     Note: PIE callbacks are not issued for DATA Calls, only PSTN and SIP calls.
     /// </summary>
-    public class PromptInputEvent
+    public class PromptInputEvent : IVoiceEvent
     {
         /// <summary>
         ///     Must have the value pie.
         /// </summary>
         [JsonPropertyName("event")]
-        public string? Event { get; set; }
+        public EventType? Event { get; set; }
 
         /// <summary>
         ///     The unique ID assigned to this call.