refactor: multiple

refactor: TimeOnly JSON converter added - regularizes record types
refactor: Strongly typed SignalR hub - removes client method name strings
chore: Redundant file cleanup

TrafficLightsSignalR/Hubs/ILightHub.cs

@@ -0,0 +1,8 @@
+namespace TrafficLightsSignalR.Hubs
+{
+    public interface ILightHub
+    {
+        Task ReceiveStateUpdate(TrafficLightState state);
+        Task ReceiveServerState(TrafficLightState? state);
+    }
+}

TrafficLightsSignalR/Hubs/LightHub.cs

@@ -4,13 +4,22 @@ using TrafficLightsSignalR.Schema;
 
 namespace TrafficLightsSignalR.Hubs
 {
-    public class LightHub(ITrafficLightStateService stateService) : Hub
+    public class LightHub : Hub<ILightHub>
     {
-        private readonly ITrafficLightStateService _stateService = stateService;
+        private readonly ITrafficLightStateService _stateService;
+        private readonly ILogger<LightHub> _logger;
+
+        public LightHub(ITrafficLightStateService stateService, ILogger<LightHub> logger)
+        {
+            _stateService = stateService;
+            _logger = logger;
+        }
 
         public async Task GetServerState(string connectionId)
         {
-            await Clients.Client(connectionId).SendAsync("ReceiveServerState", _stateService.GetCurrentTrafficLightState());
+            var currentState = _stateService.GetCurrentTrafficLightState();
+            _logger.LogInformation($"Request for server state received, current state null?: ${currentState is null}");
+            await Clients.Client(connectionId).ReceiveServerState(currentState);
         }
     }
 }

TrafficLightsSignalR/ITrafficLightStateService.cs

@@ -3,6 +3,6 @@
     public interface ITrafficLightStateService
     {
         public void SetCurrentTrafficLightState(TrafficLightState currentTrafficLightState);
-        public TrafficLightState GetCurrentTrafficLightState();
+        public TrafficLightState? GetCurrentTrafficLightState();
     }
 }

TrafficLightsSignalR/Pages/Privacy.cshtml

@@ -1,8 +0,0 @@
-@page
-@model PrivacyModel
-@{
-    ViewData["Title"] = "Privacy Policy";
-}
-<h1>@ViewData["Title"]</h1>
-
-<p>Use this page to detail your site's privacy policy.</p>

TrafficLightsSignalR/Pages/Privacy.cshtml.cs

@@ -1,20 +0,0 @@
-using Microsoft.AspNetCore.Mvc;
-using Microsoft.AspNetCore.Mvc.RazorPages;
-
-namespace TrafficLightsSignalR.Pages
-{
-    public class PrivacyModel : PageModel
-    {
-        private readonly ILogger<PrivacyModel> _logger;
-
-        public PrivacyModel(ILogger<PrivacyModel> logger)
-        {
-            _logger = logger;
-        }
-
-        public void OnGet()
-        {
-        }
-    }
-
-}

TrafficLightsSignalR/Pages/Shared/_Layout.cshtml

@@ -38,7 +38,7 @@
 
     <footer class="border-top footer text-muted">
         <div class="container">
-            &copy; 2024 - TrafficLightsSignalR - <a asp-area="" asp-page="/Privacy">Privacy</a>
+            &copy; 2024 - TrafficLightsSignalR
         </div>
     </footer>
 

TrafficLightsSignalR/Schema/Period.cs

@@ -3,12 +3,9 @@ using System.Text.Json.Serialization;
 
 namespace TrafficLightsSignalR.Schema
 {
-    public class Period
+    public record Period(
-    {
+        string Name,
-        public string Name { get; set; } = "";
+        string VerboseName,
-        public string VerboseName { get; set; } = "";
+        TimeOnly TimeStart,
-        public string TimeStart { get; set; } = "";
+        List<State> States);
-        public TimeOnly TimeStartParsed;
-        public List<State> States { get; set; } = [];
-    }
 }

TrafficLightsSignalR/Schema/State.cs

@@ -1,12 +1,10 @@
  namespace TrafficLightsSignalR.Schema
 {
-    public record State
+    public record State(
-    {
+        int Duration,
-        public int Duration { get; set; } = -1;
+        string North,
-        public string North { get; set; } = "";
+        string South,
-        public string South { get; set; } = "";
+        string East,
-        public string East { get; set; } = "";
+        string West,
-        public string West { get; set; } = "";
+        string NorthRight);
-        public string NorthRight { get; set; } = "";
-    }
 }

TrafficLightsSignalR/Schema/TimeOnlyConverter.cs

@@ -0,0 +1,28 @@
+using System.Text.Json.Serialization;
+using System.Text.Json;
+
+namespace TrafficLightsSignalR.Schema
+{
+    public class TimeOnlyConverter : JsonConverter<TimeOnly>
+    {
+        private const string TimeFormat = "HH:mm"; 
+
+        public override TimeOnly Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        {
+            string timeStr = reader.GetString() ?? throw new JsonException("Invalid time format - null string received.");
+
+            if (TimeOnly.TryParseExact(timeStr, TimeFormat, null, System.Globalization.DateTimeStyles.None, out TimeOnly time))
+            {
+                return time;
+            }
+
+            throw new JsonException("Invalid time format. Expected format: HH:mm");
+        }
+
+        public override void Write(Utf8JsonWriter writer, TimeOnly value, JsonSerializerOptions options)
+        {
+            writer.WriteStringValue(value.ToString(TimeFormat));
+        }
+    }
+
+}

TrafficLightsSignalR/TrafficLightStateService.cs

@@ -1,32 +1,29 @@
-namespace TrafficLightsSignalR
+using Microsoft.AspNetCore.SignalR;
+using TrafficLightsSignalR.Hubs;
+using TrafficLightsSignalR.Schema;
+
+namespace TrafficLightsSignalR
 {
     public class TrafficLightStateService : ITrafficLightStateService
     {
-        // string objects are immutable
+        private readonly IHubContext<LightHub, ILightHub> _hubContext;
-        protected TrafficLightState _state;
+        protected TrafficLightState? _state;
 
-        public TrafficLightStateService()
+        public TrafficLightStateService(IHubContext<LightHub, ILightHub> hubContext)
         {
-            _state = new TrafficLightState(
+            _hubContext = hubContext;
-                new Schema.Period(),
-                new Schema.State(),
-                -1,
-                0.0,
-                -1,
-                "",
-                0.0,
-                -1,
-                -1);
         }
 
         public void SetCurrentTrafficLightState(TrafficLightState currentTrafficLightState)
         {
             _state = currentTrafficLightState;
+            _hubContext.Clients.All.ReceiveStateUpdate(_state);
         }
 
-        public TrafficLightState GetCurrentTrafficLightState()
+        public TrafficLightState? GetCurrentTrafficLightState()
         {
             return _state;
         }
     }
 }
+

TrafficLightsSignalR/TrafficLightsHostedService.cs

@@ -6,7 +6,7 @@ using TrafficLightsSignalR.Schema;
 
 namespace TrafficLightsSignalR
 {
-    public class TrafficLightsHostedService(IHubContext<LightHub> hubContext, ITrafficLightStateService stateService, IConfiguration configuration, ILogger<TrafficLightsHostedService> logger) : BackgroundService
+    public class TrafficLightsHostedService(ITrafficLightStateService stateService, IConfiguration configuration, ILogger<TrafficLightsHostedService> logger) : BackgroundService
     {
         // Simulation constants
         const long TICKS_PER_SECOND = 10000000;
@@ -15,7 +15,6 @@ namespace TrafficLightsSignalR
 
         // Interconnects
         private readonly ILogger<TrafficLightsHostedService> _logger = logger;
-        private readonly IHubContext<LightHub> _hubContext = hubContext;
         private readonly ITrafficLightStateService _stateService = stateService;
         private readonly IConfiguration _configuration = configuration;
 
@@ -29,7 +28,26 @@ namespace TrafficLightsSignalR
         private void UpdateState(TrafficLightState state)
         {
             _stateService.SetCurrentTrafficLightState(state);
-            _ = _hubContext.Clients.All.SendAsync("ReceiveStateUpdate", state);
+        }
+
+        private TrafficLightState CreateStateRecord(Period currentPeriod, State currentState, int currentStateIndex, long nextChangeoverTicks, DateTime startSimulationDateTime, DateTime currentSimulationDateTime)
+        {
+            return new TrafficLightState(
+                currentPeriod,
+                currentState,
+                currentStateIndex,
+                // Seconds until next changeover
+                (nextChangeoverTicks - DateTime.UtcNow.Ticks) / (double)TICKS_PER_SECOND,
+                // Next changeover timestamp in UNIX time, millisecond granularity
+                (nextChangeoverTicks - EPOCH_TICKS) / (TICKS_PER_SECOND / 1000), // Division by 1000 -> needs to be in ms
+                                                                                 // Current simulation time string, formatted for display
+                TimeOnly.FromDateTime(currentSimulationDateTime).ToString(),
+                // Current time factor
+                _timeFactor,
+                // Current simulated timestamp in UNIX time, millisecond granularity
+                (currentSimulationDateTime.Ticks - EPOCH_TICKS) / (TICKS_PER_SECOND / 1000), // Division by 1000 -> needs to be in ms
+                                                                                             // Start timestamp (simulation time) in UNIX time, millisecond granularity
+                (startSimulationDateTime.Ticks - EPOCH_TICKS) / (TICKS_PER_SECOND / 1000)); // Division by 1000 -> needs to be in ms
         }
 
         [MemberNotNull(nameof(_periodData))]
@@ -46,22 +64,19 @@ namespace TrafficLightsSignalR
             // Load and deserialised JSON data from file
             var periodDataFilename = _configuration.GetValue<string>("PeriodConfigurationFile") ?? throw new InvalidOperationException("Unable to find period data filename (PeriodConfigurationFile) in configuration -> please check application settings");
             var periodDataStream = File.OpenRead(periodDataFilename);
-            _periodData = JsonSerializer.Deserialize<List<Period>>(periodDataStream); // may throw JsonException
+
+            var serializerOptions = new JsonSerializerOptions { Converters = { new TimeOnlyConverter() } };
+            _periodData = JsonSerializer.Deserialize<List<Period>>(periodDataStream, serializerOptions); // may throw JsonException
             if (_periodData is null)
             {
                 throw new InvalidOperationException($"JSON deserialisation returned no data available in given configuration file: {periodDataFilename}");
             }
+            periodDataStream.Close();
 
             // Parse file for convenience
             foreach (Period period in _periodData)
             {
-                timeParseSuccess = TimeOnly.TryParse(period.TimeStart, out period.TimeStartParsed);
+                _logger.LogInformation($"Period loaded - name: '{period.Name}', timestart: '{period.TimeStart}', parsed timestart: {period.TimeStart}, parse success: {timeParseSuccess}");
-                if (!timeParseSuccess)
-                {
-                    throw new InvalidOperationException($"Unable to parse time start string in period data: ${period.TimeStart}");
-                }
-                
-                _logger.LogInformation($"Period found with name: '{period.Name}', timestart: '{period.TimeStart}', parsed timestart: {period.TimeStartParsed}, parse success: {timeParseSuccess}");
                 
                 foreach (State state in period.States)
                 {
@@ -82,7 +97,7 @@ namespace TrafficLightsSignalR
                 {
                     return index;
                 }
-                if (testTime >= _periodData[index].TimeStartParsed && testTime < _periodData[index + 1].TimeStartParsed)
+                if (testTime >= _periodData[index].TimeStart && testTime < _periodData[index + 1].TimeStart)
                 {
                     return index;
                 }
@@ -110,10 +125,10 @@ namespace TrafficLightsSignalR
             _logger.LogInformation($"Next changeover second(s): {TimeSpan.FromTicks(nextChangeoverTicks - startTicks)}");
             _logger.LogInformation($"Start simulation DT: {startSimulationDateTime}");
 
+            UpdateState(CreateStateRecord(_periodData[currentPeriodIndex], _periodData[currentPeriodIndex].States[currentStateIndex], currentStateIndex, nextChangeoverTicks, startSimulationDateTime, startSimulationDateTime));
+
             while (!cancellationToken.IsCancellationRequested)
             {
-                // _logger.LogInformation("Working behind the scenes...");
-                // _stateService.SetCurrentTrafficLightState(string.Format("Thoughts about life, the universe, and everything! [ {0} ]", DateTime.Now));
                 now = DateTime.UtcNow;
                 long nowTicks = now.Ticks;
 
@@ -139,17 +154,7 @@ namespace TrafficLightsSignalR
                     nextChangeoverTicks = nowTicks + (long)((_periodData[currentPeriodIndex].States[currentStateIndex].Duration * TICKS_PER_SECOND) / _timeFactor);
                     _logger.LogInformation($"  Next changeover in {_periodData[currentPeriodIndex].States[currentStateIndex].Duration} simulation second(s)");
 
-                    var currentState = new TrafficLightState(
+                    UpdateState(CreateStateRecord(_periodData[currentPeriodIndex], _periodData[currentPeriodIndex].States[currentStateIndex], currentStateIndex, nextChangeoverTicks, startSimulationDateTime, currentSimulationDateTime));
-                        _periodData[currentPeriodIndex],
-                        _periodData[currentPeriodIndex].States[currentStateIndex],
-                        currentStateIndex,
-                        (nextChangeoverTicks - DateTime.UtcNow.Ticks) / (double)TICKS_PER_SECOND,
-                        (nextChangeoverTicks - EPOCH_TICKS) / (TICKS_PER_SECOND / 1000), // Division by 1000 -> needs to be in ms
-                        TimeOnly.FromDateTime(currentSimulationDateTime).ToString(),
-                        _timeFactor,
-                        (currentSimulationDateTime.Ticks - EPOCH_TICKS) / (TICKS_PER_SECOND / 1000), // Division by 1000 -> needs to be in ms
-                        (startSimulationDateTime.Ticks - EPOCH_TICKS) / (TICKS_PER_SECOND / 1000)); // Division by 1000 -> needs to be in ms
-                    UpdateState(currentState);
                 }
 
                 await Task.Delay((int)((1000 / UPDATES_PER_SIMULATED_SECOND) / _timeFactor), cancellationToken);

TrafficLightsSignalR/TrafficLightsState.cs

@@ -3,21 +3,6 @@ using TrafficLightsSignalR.Schema;
 
 namespace TrafficLightsSignalR
 {
-    /*
-    public record TrafficLightsState
-    {
-        public Period CurrentPeriod { get; init; }
-        public State CurrentState { get; init; }
-        public int CurrentStateIndex { get; init; }
-        public double SecondsUntilChangeover { get; init; }
-        public long NextChangeoverTimestampMs { get; init; }
-        public string CurrentSimulationTime { get; init; } // UTC
-        public double TimeFactor { get; init; }
-        public long CurrentSimulationTimestampMs { get; init; } // UNIX epoch timestamp (UTC in milliseconds)
-        public long StartSimulationTimestampMs { get; init; } // UNIX epoch timestamp (UTC in milliseconds)
-
-    }
-    */
     public record TrafficLightState(
         Period CurrentPeriod,
         State CurrentState,

TrafficLightsSignalR/wwwroot/js/lights.js

@@ -8,16 +8,21 @@ var nextUpdateTime = null;
 var connection = new signalR.HubConnectionBuilder().withUrl("/lightHub").build();
 
 connection.on("ReceiveStateUpdate", function (stateData) {
-    console.log("Update pushed.");
+    console.log("Received pushed update.");
     updateView(stateData);
 });
 
 connection.on("ReceiveServerState", function (stateData) {
-    console.log("Recevied requested server state...")
+    console.log("Recevied requested server state...");
+    if (stateData == null) {
+        console.log("State not yet initialized, not updating.");
+        return;
+    }
     updateView(stateData);
 });
     
 connection.start().then(function () {
+    console.log("Connection started, requesting server state...");
     connection.invoke("GetServerState", connection.connectionId).catch(function (err) {
         return console.error(err.toString());
     });
@@ -25,23 +30,6 @@ connection.start().then(function () {
     return console.error(err.toString());
 });
 
-document.getElementById("sendButton").addEventListener("click", function (event) {
-    var user = document.getElementById("userInput").value;
-    var message = document.getElementById("messageInput").value;
-    connection.invoke("SendMessage", user, message).catch(function (err) {
-        return console.error(err.toString());
-    });
-    event.preventDefault();
-});
-
-document.getElementById("updateButton").addEventListener("click", function (event) {
-    var connectionId = connection.connectionId;
-    connection.invoke("GetServerState", connectionId).catch(function (err) {
-        return console.error(err.toString());
-    });
-    event.preventDefault();
-});
-
 function sleep(ms) {
     return new Promise(resolve => setTimeout(resolve, ms))
 }