Change strings to date time offset

Services/ITransportService.cs

@@ -4,11 +4,11 @@ namespace ShiftScheduler.Services
 {
     public interface ITransportService
     {
-        Task<TransportConnection?> GetConnectionAsync(DateTime shiftStartTime);
+        Task<TransportConnection?> GetConnectionAsync(DateTimeOffset shiftStartTime);
     }
     
     public interface ITransportApiService
     {
-        Task<TransportConnection?> GetConnectionAsync(DateTime shiftStartTime);
+        Task<TransportConnection?> GetConnectionAsync(DateTimeOffset shiftStartTime);
     }
 }

Services/IcsExportService.cs

@@ -26,7 +26,7 @@ namespace ShiftScheduler.Services
                     var summary = $"{shift.Name} (Morning)";
                     var description = "";
 
-                    if (shiftWithTransport.MorningTransport != null && !string.IsNullOrEmpty(shiftWithTransport.MorningTransport.DepartureTime))
+                    if (shiftWithTransport.MorningTransport != null)
                     {
                         var transportSummary = FormatTransportInfo(shiftWithTransport.MorningTransport);
                         description = $"Transport: {transportSummary}";
@@ -47,7 +47,7 @@ namespace ShiftScheduler.Services
                     var summary = $"{shift.Name} (Afternoon)";
                     var description = "";
 
-                    if (shiftWithTransport.AfternoonTransport != null && !string.IsNullOrEmpty(shiftWithTransport.AfternoonTransport.DepartureTime))
+                    if (shiftWithTransport.AfternoonTransport != null)
                     {
                         var transportSummary = FormatTransportInfo(shiftWithTransport.AfternoonTransport);
                         description = $"Transport: {transportSummary}";
@@ -68,9 +68,8 @@ namespace ShiftScheduler.Services
 
         private string FormatTransportInfo(TransportConnection transport)
         {
-            var departure = DateTime.TryParse(transport.DepartureTime, out var dep) ? dep.ToString("HH:mm") : transport.DepartureTime;
+            var departure =transport.DepartureTime.ToString("HH:mm");
-            var arrival = DateTime.TryParse(transport.ArrivalTime, out var arr) ? arr.ToString("HH:mm") : transport.ArrivalTime;
+            var arrival = transport.ArrivalTime.ToString("HH:mm");
-            
             return $"{departure} → {arrival}";
         }
     }

Services/PdfExportService.cs

@@ -176,13 +176,13 @@ namespace ShiftScheduler.Services
 
             var transportLines = new List<string>();
 
-            if (shiftWithTransport.MorningTransport != null && !string.IsNullOrEmpty(shiftWithTransport.MorningTransport.DepartureTime))
+            if (shiftWithTransport.MorningTransport != null)
             {
                 var morningInfo = FormatTransportConnection(shiftWithTransport.MorningTransport);
                 transportLines.Add(morningInfo);
             }
 
-            if (shiftWithTransport.AfternoonTransport != null && !string.IsNullOrEmpty(shiftWithTransport.AfternoonTransport.DepartureTime))
+            if (shiftWithTransport.AfternoonTransport != null)
             {
                 var afternoonInfo = FormatTransportConnection(shiftWithTransport.AfternoonTransport);
                 transportLines.Add(afternoonInfo);
@@ -193,9 +193,8 @@ namespace ShiftScheduler.Services
 
         private static string FormatTransportConnection(TransportConnection transport)
         {
-            var departure = DateTime.TryParse(transport.DepartureTime, out var dep) ? dep.ToString("HH:mm") : transport.DepartureTime;
+            var departure = transport.DepartureTime.ToString("HH:mm");
-            var arrival = DateTime.TryParse(transport.ArrivalTime, out var arr) ? arr.ToString("HH:mm") : transport.ArrivalTime;
+            var arrival = transport.ArrivalTime.ToString("HH:mm");
-
             return $"🚂 {departure}→{arrival}";
         }
 

Services/TransportApiService.cs

@@ -1,3 +1,4 @@
+using System.Globalization;
 using System.Text.Json;
 using Microsoft.Extensions.Logging;
 using ShiftScheduler.Shared;
@@ -6,7 +7,7 @@ namespace ShiftScheduler.Services
 {
     public class TransportApiService(HttpClient httpClient, IConfigurationService configurationService, ILogger<TransportApiService> logger) : ITransportApiService
     {
-        public async Task<TransportConnection?> GetConnectionAsync(DateTime shiftStartTime)
+        public async Task<TransportConnection?> GetConnectionAsync(DateTimeOffset shiftStartTime)
         {
             var config = configurationService.GetTransportConfiguration();
             
@@ -45,11 +46,12 @@ namespace ShiftScheduler.Services
             if (apiConnection == null)
                 return new TransportConnection();
 
+            var formats = new[] { @"dd'd'hh\:mm\:ss", @"d'd'hh\:mm\:ss" };
             return new TransportConnection
             {
-                DepartureTime = apiConnection.From?.Departure ?? string.Empty,
+                DepartureTime = DateTimeOffset.Parse(apiConnection.From!.Departure),
-                ArrivalTime = apiConnection.To?.Arrival ?? string.Empty,
+                ArrivalTime = DateTimeOffset.Parse(apiConnection.To!.Arrival),
-                Duration = apiConnection.Duration,
+                Duration = TimeSpan.ParseExact(apiConnection.Duration, formats, CultureInfo.InvariantCulture),
                 Platform = apiConnection.From?.Platform ?? string.Empty,
             };
         }

Services/TransportConnectionCalculator.cs

@@ -1,11 +1,10 @@
-using System.Globalization;
 using Microsoft.Extensions.Logging;
 using ShiftScheduler.Shared;
 
 namespace ShiftScheduler.Services;
 
 public record ConnectionPickArgument(
-    DateTime ShiftStartTime,
+    DateTimeOffset ShiftStartTime,
     int SafetyBufferMinutes,
     int MaxEarlyArrivalMinutes,
     int MaxLateArrivalMinutes)
@@ -35,35 +34,31 @@ public static class TransportConnectionCalculator
 
         foreach (var connection in connections)
         {
-            if (DateTime.TryParse(connection.ArrivalTime, out var arrivalTime))
+            if (connection.ArrivalTime <= latestArrivalTime)
-            {
-                if (arrivalTime <= latestArrivalTime)
             {
                 validConnections.Add(connection);
             }
-                else if (arrivalTime <= latestAcceptableTime)
+            else if (connection.ArrivalTime <= latestAcceptableTime)
             {
                 lateValidConnections.Add(connection);
             }
         }
-        }
 
         // If we have valid connections (arriving before latest arrival time)
         if (validConnections.Count > 0)
         {
             var sortedValid = validConnections
-                .OrderBy(c => DateTime.Parse(c.ArrivalTime ?? "00:00"))
+                .OrderBy(c => c.ArrivalTime)
                 .ToList();
 
             var bestValidConnection = sortedValid.Last();
-            var bestValidArrivalTime = DateTime.Parse(bestValidConnection.ArrivalTime!);
 
             // Check if the best valid connection arrives too early (more than maxEarlyArrivalMinutes before shift)
-            if (bestValidArrivalTime < earliestAcceptableTime && lateValidConnections.Count > 0)
+            if (bestValidConnection.ArrivalTime < earliestAcceptableTime && lateValidConnections.Count > 0)
             {
                 // Return the earliest connection that arrives after latest arrival time but within acceptable range
                 var sortedLateValid = lateValidConnections
-                    .OrderBy(c => DateTime.Parse(c.ArrivalTime ?? "23:59"))
+                    .OrderBy(c => c.ArrivalTime)
                     .ToList();
                 
                 return sortedLateValid.First();
@@ -76,7 +71,7 @@ public static class TransportConnectionCalculator
         if (lateValidConnections.Count > 0)
         {
             var sortedLateValid = lateValidConnections
-                .OrderBy(c => DateTime.Parse(c.ArrivalTime ?? "23:59"))
+                .OrderBy(c => c.ArrivalTime)
                 .ToList();
             
             return sortedLateValid.First();

Services/TransportService.cs

@@ -5,7 +5,7 @@ namespace ShiftScheduler.Services
 {
     public class TransportService(ITransportApiService transportService, IConfigurationService configurationService, IMemoryCache cache) : ITransportService
     {
-        public async Task<TransportConnection?> GetConnectionAsync(DateTime shiftStartTime)
+        public async Task<TransportConnection?> GetConnectionAsync(DateTimeOffset shiftStartTime)
         {
             var config = configurationService.GetTransportConfiguration();
             var searchDate = shiftStartTime.ToString("yyyy-MM-dd");

Shared/ShiftWithTransport.cs

@@ -19,10 +19,8 @@ namespace ShiftScheduler.Shared
         
         private string FormatTransportSummary(TransportConnection connection)
         {
-            if (string.IsNullOrEmpty(connection.DepartureTime)) return string.Empty;
+            var departure = connection.DepartureTime.ToString("HH:mm");
-            
+            var arrival = connection.ArrivalTime.ToString("HH:mm");
-            var departure = DateTime.TryParse(connection.DepartureTime, out var dep) ? dep.ToString("HH:mm") : connection.DepartureTime;
-            var arrival = DateTime.TryParse(connection.ArrivalTime, out var arr) ? arr.ToString("HH:mm") : connection.ArrivalTime;
             return $"{departure}→{arrival}";
         }
     }

Shared/TransportModels.cs

@@ -20,12 +20,12 @@ namespace ShiftScheduler.Shared
 
         public TransportConnection(string arrivalTime)
         {
-            ArrivalTime = arrivalTime;
+            ArrivalTime = DateTimeOffset.Parse(arrivalTime);
         }
 
-        public string DepartureTime { get; set; } = string.Empty;
+        public DateTimeOffset DepartureTime { get; set; }
-        public string ArrivalTime { get; set; } = string.Empty;
+        public DateTimeOffset ArrivalTime { get; set; }
-        public string Duration { get; set; } = string.Empty;
+        public TimeSpan Duration { get; set; }
         public string? Platform { get; set; } = string.Empty;
 
         public override string ToString()

ShiftScheduler.Services.Tests/TransportApiServiceTests.cs

@@ -58,9 +58,9 @@ public class TransportApiServiceTests
 
         // Assert
         result.ShouldNotBeNull();
-        result.DepartureTime.ShouldBe("2023-12-15T06:45:00");
+        result.DepartureTime.ShouldBe(T("2023-12-15T06:45:00"));
-        result.ArrivalTime.ShouldBe("2023-12-15T07:30:00");
+        result.ArrivalTime.ShouldBe(T("2023-12-15T07:30:00"));
-        result.Duration.ShouldBe("00:45:00");
+        result.Duration.ShouldBe(TimeSpan.Parse("00:45:00"));
         result.Platform.ShouldBe("5");
     }
 
@@ -115,7 +115,7 @@ public class TransportApiServiceTests
         // Latest acceptable arrival: 8:00 - 30 min = 7:30
         // Valid connections: 07:15 and 07:25 (both arrive before 7:30)
         // Algorithm should return the latest valid: 07:25
-        result.ArrivalTime.ShouldBe("2023-12-15T07:25:00");
+        result.ArrivalTime.ShouldBe(T("2023-12-15T07:25:00"));
     }
 
     private void SetupHttpMockResponse(HttpStatusCode statusCode, string content)
@@ -151,7 +151,7 @@ public class TransportApiServiceTests
                         Arrival = "2023-12-15T07:30:00",
                         Platform = "3"
                     },
-                    Duration = "00:45:00",
+                    Duration = "00d00:45:00",
                     Sections = new List<TransportApiSection>
                     {
                         new TransportApiSection
@@ -202,7 +202,7 @@ public class TransportApiServiceTests
                         Arrival = "2023-12-15T07:15:00",
                         Platform = "3"
                     },
-                    Duration = "00:45:00"
+                    Duration = "00d00:45:00"
                 },
                 // Later valid connection - should be selected as best
                 new TransportApiConnection
@@ -219,7 +219,7 @@ public class TransportApiServiceTests
                         Arrival = "2023-12-15T07:25:00",
                         Platform = "2"
                     },
-                    Duration = "00:45:00"
+                    Duration = "00d00:45:00"
                 },
                 // Too late connection - invalid (arrives after 07:30 which is shift start - 30 min buffer)
                 new TransportApiConnection
@@ -236,9 +236,14 @@ public class TransportApiServiceTests
                         Arrival = "2023-12-15T07:35:00",
                         Platform = "1"
                     },
-                    Duration = "00:45:00"
+                    Duration = "00d00:45:00"
                 }
             }
         };
     }
+    
+    private DateTimeOffset T(string dateTimeString)
+    {
+        return DateTimeOffset.Parse(dateTimeString);
+    }
 }

ShiftScheduler.Services.Tests/TransportConnectionCalculatorTests.cs

@@ -20,7 +20,7 @@ public class TransportConnectionCalculatorTests
             new(arrivalTime: "2023-12-15T07:25:00"), // Should be selected (latest valid)
             new(arrivalTime: "2023-12-15T08:05:00") // Too late
         };
-        var shiftStartTime = new DateTime(2023, 12, 15, 8, 0, 0);
+        var shiftStartTime = T("2023-12-15T08:00:00");
 
         // Act
         var result = TransportConnectionCalculator.FindBestConnection(
@@ -30,7 +30,7 @@ public class TransportConnectionCalculatorTests
 
         // Assert
         result.ShouldNotBeNull();
-        result.ArrivalTime.ShouldBe("2023-12-15T07:25:00");
+        result.ArrivalTime.ShouldBe(T("2023-12-15T07:25:00"));
     }
 
     [Fact]
@@ -42,7 +42,7 @@ public class TransportConnectionCalculatorTests
             new(arrivalTime: "2023-12-15T06:45:00"), // Too early (more than 60 min before 8:00)
             new(arrivalTime: "2023-12-15T08:05:00") // Within acceptable late range (15 min after 8:00)
         };
-        var shiftStartTime = new DateTime(2023, 12, 15, 8, 0, 0);
+        var shiftStartTime = T("2023-12-15T08:00:00");
 
         // Act
         var result = TransportConnectionCalculator.FindBestConnection(
@@ -52,7 +52,7 @@ public class TransportConnectionCalculatorTests
 
         // Assert
         result.ShouldNotBeNull();
-        result.ArrivalTime.ShouldBe("2023-12-15T08:05:00");
+        result.ArrivalTime.ShouldBe(T("2023-12-15T08:05:00"));
     }
 
     [Fact]
@@ -65,7 +65,7 @@ public class TransportConnectionCalculatorTests
             new(arrivalTime: "2023-12-15T08:05:00"), // Should be selected (earliest late)
             new(arrivalTime: "2023-12-15T08:12:00")
         };
-        var shiftStartTime = new DateTime(2023, 12, 15, 8, 0, 0);
+        var shiftStartTime = T("2023-12-15T08:00:00");
 
         // Act
         var result = TransportConnectionCalculator.FindBestConnection(
@@ -75,7 +75,7 @@ public class TransportConnectionCalculatorTests
 
         // Assert
         result.ShouldNotBeNull();
-        result.ArrivalTime.ShouldBe("2023-12-15T08:05:00");
+        result.ArrivalTime.ShouldBe(T("2023-12-15T08:05:00"));
     }
 
     [Fact]
@@ -88,7 +88,7 @@ public class TransportConnectionCalculatorTests
             new(arrivalTime: "2023-12-15T08:25:00"),
             new(arrivalTime: "2023-12-15T08:30:00")
         };
-        var shiftStartTime = new DateTime(2023, 12, 15, 8, 0, 0);
+        var shiftStartTime = T("2023-12-15T08:00:00");
 
         // Act
         var result = TransportConnectionCalculator.FindBestConnection(
@@ -109,7 +109,7 @@ public class TransportConnectionCalculatorTests
             new(arrivalTime: "2023-12-15T07:20:00"), // 40 min before shift - acceptable
             new(arrivalTime: "2023-12-15T08:05:00") // 5 min after shift
         };
-        var shiftStartTime = new DateTime(2023, 12, 15, 8, 0, 0);
+        var shiftStartTime = T("2023-12-15T08:00:00");
 
         // Act
         var result = TransportConnectionCalculator.FindBestConnection(
@@ -119,14 +119,14 @@ public class TransportConnectionCalculatorTests
 
         // Assert
         result.ShouldNotBeNull();
-        result.ArrivalTime.ShouldBe("2023-12-15T07:20:00");
+        result.ArrivalTime.ShouldBe(T("2023-12-15T07:20:00"));
     }
 
     [Fact]
     public void FindBestConnectionEnhanced_WithEmptyConnections_ShouldReturnNull()
     {
         // Arrange
-        var shiftStartTime = new DateTime(2023, 12, 15, 8, 0, 0);
+        var shiftStartTime = T("2023-12-15T08:00:00");
 
         // Act
         var result = TransportConnectionCalculator.FindBestConnection(
@@ -149,7 +149,7 @@ public class TransportConnectionCalculatorTests
             new(arrivalTime: "2023-12-15T08:05:00"), // Late but acceptable
             new(arrivalTime: "2023-12-15T08:20:00") // Too late
         };
-        var shiftStartTime = new DateTime(2023, 12, 15, 8, 0, 0);
+        var shiftStartTime = T("2023-12-15T08:00:00");
 
         // Act - MaxEarlyArrivalMinutes = 30, so earliest acceptable is 7:30
         var result = TransportConnectionCalculator.FindBestConnection(
@@ -159,6 +159,11 @@ public class TransportConnectionCalculatorTests
 
         // Assert - 7:25 arrives at 7:25, which is 35 min before shift (more than 30 min), so should prefer late connection
         result.ShouldNotBeNull();
-        result.ArrivalTime.ShouldBe("2023-12-15T08:05:00");
+        result.ArrivalTime.ShouldBe(T("2023-12-15T08:05:00"));
+    }
+    
+    private DateTimeOffset T(string dateTimeString)
+    {
+        return DateTimeOffset.Parse(dateTimeString);
     }
 }

ShiftScheduler.Services.Tests/TransportServiceTests.cs

@@ -46,9 +46,9 @@ public class TransportServiceTests
         var shiftStartTime = new DateTime(2023, 12, 15, 8, 0, 0);
         var connection = new TransportConnection
         {
-            DepartureTime = "2023-12-15T06:45:00",
+            DepartureTime = T("2023-12-15T06:45:00"),
-            ArrivalTime = "2023-12-15T07:30:00",
+            ArrivalTime = T("2023-12-15T07:30:00"),
-            Duration = "00:45:00",
+            Duration = TimeSpan.Parse("00:45:00"),
             Platform = "5"
         };
         
@@ -100,11 +100,11 @@ public class TransportServiceTests
     public async Task GetConnectionAsync_WithDifferentDates_ShouldCreateSeparateCacheEntries()
     {
         // Arrange
-        var shiftStartTime1 = new DateTime(2023, 12, 15, 8, 0, 0);
+        var shiftStartTime1 = T("2023-12-15T08:00:00");
-        var shiftStartTime2 = new DateTime(2023, 12, 16, 8, 0, 0);
+        var shiftStartTime2 = T("2023-12-16T08:00:00");
         
-        var connection1 = new TransportConnection { ArrivalTime = "2023-12-15T07:30:00" };
+        var connection1 = new TransportConnection { ArrivalTime = T("2023-12-15T07:30:00") };
-        var connection2 = new TransportConnection { ArrivalTime = "2023-12-16T07:30:00" };
+        var connection2 = new TransportConnection { ArrivalTime = T("2023-12-16T07:30:00") };
         
         _transportServiceMock
             .Setup(x => x.GetConnectionAsync(shiftStartTime1))
@@ -121,10 +121,15 @@ public class TransportServiceTests
         // Assert
         result1.ShouldNotBeNull();
         result2.ShouldNotBeNull();
-        result1.ArrivalTime.ShouldBe("2023-12-15T07:30:00");
+        result1.ArrivalTime.ShouldBe(T("2023-12-15T07:30:00"));
-        result2.ArrivalTime.ShouldBe("2023-12-16T07:30:00");
+        result2.ArrivalTime.ShouldBe(T("2023-12-16T07:30:00"));
         
         // Verify that transport service was called twice (different cache keys)
-        _transportServiceMock.Verify(x => x.GetConnectionAsync(It.IsAny<DateTime>()), Times.Exactly(2));
+        _transportServiceMock.Verify(x => x.GetConnectionAsync(It.IsAny<DateTimeOffset>()), Times.Exactly(2));
+    }
+
+    private DateTimeOffset T(string dateTimeString)
+    {
+        return DateTimeOffset.Parse(dateTimeString);
     }
 }