From 02a6c3bf6ae1e1a22ff0ba6a88a5ff46084b8476 Mon Sep 17 00:00:00 2001
From: Pilzinsel64 <pascal.schedel@dr-schneider.com>
Date: Wed, 14 Aug 2024 14:59:05 +0200
Subject: [PATCH] begin developing a basic message based web api

---
 Pilz.Networking/Api/ApiClient.cs              |  9 ++++
 Pilz.Networking/Api/ApiMessage.cs             | 14 ++++++
 Pilz.Networking/Api/ApiServer.cs              | 49 +++++++++++++++++++
 .../Api/DefaultMessageSerializer.cs           | 14 ++++++
 Pilz.Networking/Api/IApiClient.cs             |  6 +++
 Pilz.Networking/Api/IApiServer.cs             |  7 +++
 Pilz.Networking/Api/IMessageSerializer.cs     |  7 +++
 .../Api/MessageHandlerAttribute.cs            |  8 +++
 Pilz.Networking/Pilz.Networking.csproj        |  1 +
 9 files changed, 115 insertions(+)
 create mode 100644 Pilz.Networking/Api/ApiClient.cs
 create mode 100644 Pilz.Networking/Api/ApiMessage.cs
 create mode 100644 Pilz.Networking/Api/ApiServer.cs
 create mode 100644 Pilz.Networking/Api/DefaultMessageSerializer.cs
 create mode 100644 Pilz.Networking/Api/IApiClient.cs
 create mode 100644 Pilz.Networking/Api/IApiServer.cs
 create mode 100644 Pilz.Networking/Api/IMessageSerializer.cs
 create mode 100644 Pilz.Networking/Api/MessageHandlerAttribute.cs

diff --git a/Pilz.Networking/Api/ApiClient.cs b/Pilz.Networking/Api/ApiClient.cs
new file mode 100644
index 0000000..392a95e
--- /dev/null
+++ b/Pilz.Networking/Api/ApiClient.cs
@@ -0,0 +1,9 @@
+namespace Pilz.Networking.Api;
+
+public class ApiClient : IApiClient
+{
+    public void MakeRequest<T>(string url, T message) where T : ApiMessage
+    {
+        // ...
+    }
+}
diff --git a/Pilz.Networking/Api/ApiMessage.cs b/Pilz.Networking/Api/ApiMessage.cs
new file mode 100644
index 0000000..a1ba7d1
--- /dev/null
+++ b/Pilz.Networking/Api/ApiMessage.cs
@@ -0,0 +1,14 @@
+namespace Pilz.Networking.Api;
+
+public abstract class ApiMessage
+{
+    internal protected virtual string? Serialize(ApiMessage message)
+    {
+
+    }
+
+    internal protected virtual ApiMessage? Deserialize(string json)
+    {
+
+    }
+}
diff --git a/Pilz.Networking/Api/ApiServer.cs b/Pilz.Networking/Api/ApiServer.cs
new file mode 100644
index 0000000..4b65db1
--- /dev/null
+++ b/Pilz.Networking/Api/ApiServer.cs
@@ -0,0 +1,49 @@
+using System.Reflection;
+
+namespace Pilz.Networking.Api;
+
+public class ApiServer : ApiClient, IApiServer
+{
+    protected readonly Dictionary<string, object> handlers = [];
+    protected readonly Dictionary<Type, IMessageSerializer> serializers = [];
+
+    public IMessageSerializer Serializer { get; set; } = new DefaultMessageSerializer();
+
+    public virtual void RegisterHandler<T>(string url, T instance) where T : class
+    {
+        var methods = typeof(T).GetMethods(BindingFlags.Instance | BindingFlags.Public);
+
+        foreach (var method in methods)
+        {
+            if (method.GetCustomAttribute<MessageHandlerAttribute>() is not MessageHandlerAttribute attribute
+                || method.GetParameters().FirstOrDefault() is not ParameterInfo parameterInfo
+                || !parameterInfo.ParameterType.IsAssignableTo(typeof(ApiMessage)))
+                continue;
+
+
+            var serializer = Serializer;
+            if (attribute.Serializer is not null)
+            {
+                if (serializers.TryGetValue(attribute.Serializer, out var s) && s is not null)
+                    serializer = s;
+                else if (Activator.CreateInstance(attribute.Serializer) is IMessageSerializer ss)
+                {
+                    serializer = ss;
+                    serializers.Add(attribute.Serializer, ss);
+                }
+            }
+
+            // ...
+        }
+    }
+
+    public virtual void RegisterHandler(string url, Delegate handler)
+    {
+        // ...
+    }
+
+    protected virtual string? HandleMessage(string url, string json)
+    {
+        // ...
+    }
+}
diff --git a/Pilz.Networking/Api/DefaultMessageSerializer.cs b/Pilz.Networking/Api/DefaultMessageSerializer.cs
new file mode 100644
index 0000000..df98251
--- /dev/null
+++ b/Pilz.Networking/Api/DefaultMessageSerializer.cs
@@ -0,0 +1,14 @@
+namespace Pilz.Networking.Api;
+
+public class DefaultMessageSerializer : IMessageSerializer
+{
+    public ApiMessage? Deserialize(string json)
+    {
+        // ...
+    }
+
+    public string? Serialize(ApiMessage message)
+    {
+        // ...
+    }
+}
diff --git a/Pilz.Networking/Api/IApiClient.cs b/Pilz.Networking/Api/IApiClient.cs
new file mode 100644
index 0000000..3204398
--- /dev/null
+++ b/Pilz.Networking/Api/IApiClient.cs
@@ -0,0 +1,6 @@
+namespace Pilz.Networking.Api;
+
+public interface IApiClient
+{
+    void MakeRequest<T>(string url, T message) where T : ApiMessage;
+}
diff --git a/Pilz.Networking/Api/IApiServer.cs b/Pilz.Networking/Api/IApiServer.cs
new file mode 100644
index 0000000..dfdc4b6
--- /dev/null
+++ b/Pilz.Networking/Api/IApiServer.cs
@@ -0,0 +1,7 @@
+namespace Pilz.Networking.Api;
+
+public interface IApiServer : IApiClient
+{
+    void RegisterHandler<T>(string url, T instance) where T : class;
+    void RegisterHandler(string url, Delegate handler);
+}
diff --git a/Pilz.Networking/Api/IMessageSerializer.cs b/Pilz.Networking/Api/IMessageSerializer.cs
new file mode 100644
index 0000000..84597fa
--- /dev/null
+++ b/Pilz.Networking/Api/IMessageSerializer.cs
@@ -0,0 +1,7 @@
+namespace Pilz.Networking.Api;
+
+public interface IMessageSerializer
+{
+    string? Serialize(ApiMessage message);
+    ApiMessage? Deserialize(string json);
+}
diff --git a/Pilz.Networking/Api/MessageHandlerAttribute.cs b/Pilz.Networking/Api/MessageHandlerAttribute.cs
new file mode 100644
index 0000000..c82283b
--- /dev/null
+++ b/Pilz.Networking/Api/MessageHandlerAttribute.cs
@@ -0,0 +1,8 @@
+namespace Pilz.Networking.Api;
+
+[AttributeUsage(AttributeTargets.Method)]
+public class MessageHandlerAttribute(string url) : Attribute
+{
+    public string Url { get; set; } = url;
+    public Type? Serializer { get; set; }
+}
diff --git a/Pilz.Networking/Pilz.Networking.csproj b/Pilz.Networking/Pilz.Networking.csproj
index ba2bb7b..cad8bb1 100644
--- a/Pilz.Networking/Pilz.Networking.csproj
+++ b/Pilz.Networking/Pilz.Networking.csproj
@@ -5,6 +5,7 @@
     <TargetFrameworks>net8.0-windows</TargetFrameworks>
     <LangVersion>latest</LangVersion>
     <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
   
   <ItemGroup>