initial commit

TimetableDesigner.Backend.Events.OutboxPattern/Event.cs

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+using System.Text.Json;
+
+namespace TimetableDesigner.Backend.Events.OutboxPattern;
+
+public class Event
+{
+    public Guid Id { get; set; }
+    public required string Payload { get; set; }
+    public required string PayloadType { get; set; }
+    public DateTimeOffset OccuredOn { get; set; } = DateTimeOffset.UtcNow;
+    public DateTimeOffset? LastRetryOn { get; set; }
+    public uint RetryCount { get; set; }
+    
+    public Event(object payload)
+    {
+        Payload = JsonSerializer.Serialize(payload);
+        PayloadType = payload.GetType().FullName!;
+    }
+}

TimetableDesigner.Backend.Events.OutboxPattern/EventConfiguration.cs

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+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Metadata.Builders;
+
+namespace TimetableDesigner.Backend.Events.OutboxPattern;
+
+public class EventConfiguration : IEntityTypeConfiguration<Event>
+{
+    public void Configure(EntityTypeBuilder<Event> builder)
+    {
+        builder.HasKey(x => x.Id);
+        builder.HasIndex(x => x.Id)
+               .IsUnique();
+        builder.Property(x => x.Id)
+               .IsRequired();
+        
+        builder.Property(x => x.Payload)
+               .IsRequired();
+        
+        builder.Property(x => x.PayloadType)
+               .IsRequired();
+        
+        builder.Property(x => x.OccuredOn)
+               .IsRequired();
+        
+        builder.Property(x => x.LastRetryOn);
+        
+        builder.Property(x => x.RetryCount)
+               .IsRequired();
+    }
+}

TimetableDesigner.Backend.Events.OutboxPattern/EventOutboxSender.cs

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+using System.Text.Json;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Hosting;
+
+namespace TimetableDesigner.Backend.Events.OutboxPattern;
+
+public class EventOutboxSender<TDbContext> : BackgroundService where TDbContext : DbContext, IEventOutboxDbContext
+{
+    private readonly TDbContext  _databaseContext;
+    private readonly IEventQueuePublisher _eventQueuePublisher;
+    
+    public EventOutboxSender(TDbContext databaseContext, IEventQueuePublisher eventQueuePublisher)
+    {
+        _databaseContext = databaseContext;
+        _eventQueuePublisher = eventQueuePublisher;
+    }
+    
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            Event? eventData = await _databaseContext.Events.FirstOrDefaultAsync(x => x.LastRetryOn == null, stoppingToken)
+                            ?? await _databaseContext.Events.OrderBy(x => x.LastRetryOn).FirstOrDefaultAsync(stoppingToken);
+
+            if (eventData is null)
+            {
+                continue;
+            }
+            
+            Type payloadType = Type.GetType(eventData.PayloadType)!;
+            JsonSerializer.Deserialize(eventData.Payload, payloadType);
+
+            try
+            {
+                await _eventQueuePublisher.PublishAsync(eventData.Payload, payloadType);
+                    
+                _databaseContext.Events.Remove(eventData);
+            }
+            catch
+            {
+                eventData.LastRetryOn = DateTimeOffset.UtcNow;
+                eventData.RetryCount++;
+            }
+            finally
+            {
+                await _databaseContext.SaveChangesAsync(stoppingToken);
+            }
+        }
+    }
+}

TimetableDesigner.Backend.Events.OutboxPattern/IEventOutboxDbContext.cs

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+using Microsoft.EntityFrameworkCore;
+
+namespace TimetableDesigner.Backend.Events.OutboxPattern;
+
+public interface IEventOutboxDbContext
+{
+    DbSet<Event> Events { get; }
+}

TimetableDesigner.Backend.Events.OutboxPattern/TimetableDesigner.Backend.Events.OutboxPattern.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>net10.0</TargetFramework>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+        <Version />
+        <Title>TimetableDesigner.Backend.Events.OutboxPattern</Title>
+        <Authors>Mateusz Skoczek</Authors>
+        <PackageProjectUrl>https://github.com/TimetableDesigner</PackageProjectUrl>
+        <PackageIcon>icon.png</PackageIcon>
+        <RepositoryUrl>https://github.com/TimetableDesigner/TimetableDesigner.Backend.Events.OutboxPattern</RepositoryUrl>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <PackageReference Include="Microsoft.EntityFrameworkCore" Version="10.0.2" />
+      <PackageReference Include="Microsoft.Extensions.Hosting" Version="10.0.2" />
+      <PackageReference Include="TimetableDesigner.Backend.Events" Version="1.1.4" />
+    </ItemGroup>
+
+</Project>