3 files changed, 181 insertions, 0 deletions
diff --git a/code/source-generator/EndpointFinder.cs b/code/source-generator/EndpointFinder.cs
new file mode 100644
index 0000000..b30451e
--- /dev/null
+++ b/code/source-generator/EndpointFinder.cs
@@ -0,0 +1,17 @@
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+
+namespace I2R.Endpoints.Generator;
+
+public class EndpointFinder : ISyntaxReceiver
+{
+    public HashSet<ClassDeclarationSyntax> Endpoints { get; } = new();
+
+    public void OnVisitSyntaxNode(SyntaxNode syntaxNode) {
+        if (syntaxNode is not ClassDeclarationSyntax endpoint) return;
+        if ((endpoint.BaseList?.Types.Any(c => EndpointGenerator.IsSyncEndpoint(c.ToString())) ?? false)
+            || (endpoint.BaseList?.Types.Any(c => EndpointGenerator.IsAyncEndpoint(c.ToString())) ?? false)) {
+            Endpoints.Add(endpoint);
+        }
+    }
+}
diff --git a/code/source-generator/EndpointGenerator.cs b/code/source-generator/EndpointGenerator.cs
new file mode 100644
index 0000000..989a1c5
--- /dev/null
+++ b/code/source-generator/EndpointGenerator.cs
@@ -0,0 +1,146 @@
+using System.Text.RegularExpressions;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+
+namespace I2R.Endpoints.Generator;
+
+[Generator]
+public class EndpointGenerator : ISourceGenerator
+{
+    private const string SourceGenereatedComment = "// Generated by I2R.Endpoints, probably smart to leave it be";
+
+    public void Initialize(GeneratorInitializationContext context) {
+        context.RegisterForSyntaxNotifications(() => new EndpointFinder());
+    }
+
+    public void Execute(GeneratorExecutionContext context) {
+        var endpointClasses = ((EndpointFinder) context.SyntaxReceiver)?.Endpoints;
+        if (endpointClasses == null) {
+            context.ReportDiagnostic(CreateDebugDiagnostic("no endpoints were found"));
+            return;
+        }
+
+        foreach (var info in endpointClasses.Select(GetEndpointInfoFromClass)) {
+            context.AddSource(info.GeneratedFileName, info.IsSynchronous ? GetSyncSource(info) : GetAsyncSource(info));
+        }
+    }
+
+    private static Diagnostic CreateDebugDiagnostic(string message) {
+        var descriptor = new DiagnosticDescriptor("debug", "Debug", message, "debug", DiagnosticSeverity.Warning, true);
+        return Diagnostic.Create(descriptor, null, "");
+    }
+
+    private class EndpointInfo
+    {
+        public string BaseEndpointClassName { get; set; }
+        public bool IsSynchronous { get; set; }
+        public string GeneratedFileName { get; set; }
+    }
+
+    public static bool IsSyncEndpoint(string name) {
+        return name.StartsWith("SyncEndpoint");
+    }
+
+    public static bool IsAyncEndpoint(string name) {
+        return name.StartsWith("AsyncEndpoint");
+    }
+
+    private static EndpointInfo GetEndpointInfoFromClass(ClassDeclarationSyntax classDeclarationSyntax) {
+        var baseType = classDeclarationSyntax.BaseList?.Types.FirstOrDefault();
+        if (baseType == default) {
+            return default;
+        }
+
+        var fullTypeName = baseType.Type.ToString();
+        var className = Regex.Match(fullTypeName, "(!?<).+?(?=>)").Value.Replace("<", "");
+        return new EndpointInfo() {
+            BaseEndpointClassName = className,
+            IsSynchronous = IsSyncEndpoint(baseType.ToString()),
+            GeneratedFileName = className + ".endpoints.g.cs"
+        };
+    }
+
+    private static string GetSyncSource(EndpointInfo info) {
+        return $@"
+{SourceGenereatedComment}
+namespace {typeof(EndpointGenerator).Namespace};
+public static partial class SyncEndpoint<T{info.BaseEndpointClassName}>
+{{
+    public static class Req<TRequest>
+    {{
+        public abstract class Res<TResponse> : {info.BaseEndpointClassName}
+        {{
+            public abstract TResponse Handle(
+                TRequest request
+            );
+        }}
+
+        public abstract class NoRes : {info.BaseEndpointClassName}
+        {{
+            public abstract void Handle(
+                TRequest request
+            );
+        }}
+    }}
+
+    public static class NoReq
+    {{
+        public abstract class Res<TResponse> : {info.BaseEndpointClassName}
+        {{
+            public abstract TResponse Handle();
+        }}
+
+        public abstract class NoRes : {info.BaseEndpointClassName}
+        {{
+            public abstract void Handle();
+        }}
+    }}
+}}
+";
+    }
+
+    private static string GetAsyncSource(EndpointInfo info) {
+        return $@"
+{SourceGenereatedComment}
+namespace {typeof(EndpointGenerator).Namespace};
+public static partial class AsyncEndpoint<T>
+{{
+    public static class Req<TRequest>
+    {{
+        public abstract class Res<TResponse> : {info.BaseEndpointClassName}
+        {{
+            public abstract Task<TResponse> HandleAsync(
+                TRequest request,
+                CancellationToken cancellationToken = default
+            );
+        }}
+
+        public abstract class NoRes : {info.BaseEndpointClassName}
+        {{
+            public abstract Task HandleAsync(
+                TRequest request,
+                CancellationToken cancellationToken = default
+            );
+        }}
+    }}
+
+    public static class NoReq
+    {{
+        public abstract class Res<TResponse> : {info.BaseEndpointClassName}
+        {{
+            public abstract Task<TResponse> HandleAsync(
+                CancellationToken cancellationToken = default
+            );
+        }}
+
+        public abstract class NoRes : {info.BaseEndpointClassName}
+        {{
+            public abstract Task HandleAsync(
+                CancellationToken cancellationToken = default
+            );
+        }}
+    }}
+}}
+";
+    }
+}
diff --git a/code/source-generator/I2R.Endpoints.Generator.csproj b/code/source-generator/I2R.Endpoints.Generator.csproj
new file mode 100644
index 0000000..f67f7d3
--- /dev/null
+++ b/code/source-generator/I2R.Endpoints.Generator.csproj
@@ -0,0 +1,18 @@
+<Project Sdk="Microsoft.NET.Sdk">
+    <PropertyGroup>
+        <TargetFramework>netstandard2.0</TargetFramework>
+        <LangVersion>10</LangVersion>
+        <ImplicitUsings>true</ImplicitUsings>
+        <DevelopmentDependency>true</DevelopmentDependency>
+    </PropertyGroup>
+    <ItemGroup>
+        <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.3">
+            <PrivateAssets>all</PrivateAssets>
+            <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+        </PackageReference>
+        <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.4.0"/>
+    </ItemGroup>
+    <ItemGroup>
+        <None Include="$(OutputPath)\$(AssemblyName).dll" Pack="true" PackagePath="analyzers/dotnet/cs" Visible="false"/>
+    </ItemGroup>
+</Project>