From d1eecffcb49f5e7295c1a5bd43722ed8caf6e950 Mon Sep 17 00:00:00 2001
From: Christoph Stahl <christoph.stahl@tu-dortmund.de>
Date: Wed, 10 May 2023 15:56:27 +0200
Subject: [PATCH] Factorial

---
 src/main/java/com/example/AkkaMainSystem.java |  5 ++-
 src/main/java/com/example/C.java              | 30 +++++++++++++
 src/main/java/com/example/ExampleActor.java   | 35 ----------------
 src/main/java/com/example/Fak.java            | 41 ++++++++++++++++++
 src/main/java/com/example/FakCont.java        | 42 +++++++++++++++++++
 5 files changed, 116 insertions(+), 37 deletions(-)
 create mode 100644 src/main/java/com/example/C.java
 delete mode 100644 src/main/java/com/example/ExampleActor.java
 create mode 100644 src/main/java/com/example/Fak.java
 create mode 100644 src/main/java/com/example/FakCont.java

diff --git a/src/main/java/com/example/AkkaMainSystem.java b/src/main/java/com/example/AkkaMainSystem.java
index 7ddda70..966977a 100644
--- a/src/main/java/com/example/AkkaMainSystem.java
+++ b/src/main/java/com/example/AkkaMainSystem.java
@@ -24,10 +24,11 @@ public class AkkaMainSystem extends AbstractBehavior<AkkaMainSystem.Create> {
 
     private Behavior<Create> onCreate(Create command) {
         //#create-actors
-        ActorRef<ExampleActor.Message> a = this.getContext().spawn(ExampleActor.create("Alice"), "alice");
+        ActorRef<FakCont.Message> c = this.getContext().spawn(C.create(), "c");
+        ActorRef<Fak.Message> fak = this.getContext().spawn(Fak.create(), "fak");
         //#create-actors
 
-        a.tell(new ExampleActor.ExampleMessage(this.getContext().getSelf(),"Test123"));
+        fak.tell(new Fak.FakMessage(5, c));
         return this;
     }
 }
diff --git a/src/main/java/com/example/C.java b/src/main/java/com/example/C.java
new file mode 100644
index 0000000..5af5052
--- /dev/null
+++ b/src/main/java/com/example/C.java
@@ -0,0 +1,30 @@
+package com.example;
+
+import akka.actor.typed.Behavior;
+import akka.actor.typed.javadsl.AbstractBehavior;
+import akka.actor.typed.javadsl.ActorContext;
+import akka.actor.typed.javadsl.Behaviors;
+import akka.actor.typed.javadsl.Receive;
+
+public class C extends AbstractBehavior<FakCont.Message> {
+
+    public static Behavior<FakCont.Message> create() {
+        return Behaviors.setup(C::new);
+    }
+
+    private C(ActorContext<FakCont.Message> context) {
+        super(context);
+    }
+
+    @Override
+    public Receive<FakCont.Message> createReceive() {
+        return newReceiveBuilder()
+                .onMessage(FakCont.FakContMessage.class, this::onFakContMessage)
+                .build();
+    }
+
+    private Behavior<FakCont.Message> onFakContMessage(FakCont.FakContMessage msg) {
+        getContext().getLog().info("{}", msg.arg());
+        return this;
+    }
+}
diff --git a/src/main/java/com/example/ExampleActor.java b/src/main/java/com/example/ExampleActor.java
deleted file mode 100644
index cf56713..0000000
--- a/src/main/java/com/example/ExampleActor.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package com.example;
-
-import akka.actor.typed.ActorRef;
-import akka.actor.typed.Behavior;
-import akka.actor.typed.javadsl.*;
-
-public class ExampleActor extends AbstractBehavior<ExampleActor.Message> {
-
-    public interface Message {};
-
-    public record ExampleMessage(ActorRef<AkkaMainSystem.Create> someReference, String someString) implements Message {  }
-
-    public static Behavior<Message> create(String name) {
-        return Behaviors.setup(context -> new ExampleActor(context, name));
-    }
-
-    private final String name;
-
-    private ExampleActor(ActorContext<Message> context, String name) {
-        super(context);
-        this.name = name;
-    }
-
-    @Override
-    public Receive<Message> createReceive() {
-        return newReceiveBuilder()
-                .onMessage(ExampleMessage.class, this::onExampleMessage)
-                .build();
-    }
-
-    private Behavior<Message> onExampleMessage(ExampleMessage msg) {
-        getContext().getLog().info("I ({}) got a message: ExampleMessage({},{})", this.name, msg.someReference, msg.someString);
-        return this;
-    }
-}
diff --git a/src/main/java/com/example/Fak.java b/src/main/java/com/example/Fak.java
new file mode 100644
index 0000000..3914620
--- /dev/null
+++ b/src/main/java/com/example/Fak.java
@@ -0,0 +1,41 @@
+package com.example;
+
+import akka.actor.typed.ActorRef;
+import akka.actor.typed.Behavior;
+import akka.actor.typed.javadsl.AbstractBehavior;
+import akka.actor.typed.javadsl.ActorContext;
+import akka.actor.typed.javadsl.Behaviors;
+import akka.actor.typed.javadsl.Receive;
+
+public class Fak extends AbstractBehavior<Fak.Message> {
+
+    public interface Message {};
+
+    public record FakMessage(int val, ActorRef<FakCont.Message> cust) implements Message {  }
+
+    public static Behavior<Message> create() {
+        return Behaviors.setup(Fak::new);
+    }
+
+
+    private Fak(ActorContext<Message> context) {
+        super(context);
+    }
+
+    @Override
+    public Receive<Message> createReceive() {
+        return newReceiveBuilder()
+                .onMessage(FakMessage.class, this::onFakMessage)
+                .build();
+    }
+
+    private Behavior<Message> onFakMessage(FakMessage msg) {
+        if(msg.val == 0) {
+            msg.cust.tell(new FakCont.FakContMessage(1));
+        } else {
+            ActorRef<FakCont.Message> cont = this.getContext().spawnAnonymous(FakCont.create(msg.val, msg.cust));
+            this.getContext().getSelf().tell(new FakMessage(msg.val - 1, cont));
+        }
+        return this;
+    }
+}
diff --git a/src/main/java/com/example/FakCont.java b/src/main/java/com/example/FakCont.java
new file mode 100644
index 0000000..5f8b8ab
--- /dev/null
+++ b/src/main/java/com/example/FakCont.java
@@ -0,0 +1,42 @@
+package com.example;
+
+import akka.actor.typed.ActorRef;
+import akka.actor.typed.Behavior;
+import akka.actor.typed.javadsl.AbstractBehavior;
+import akka.actor.typed.javadsl.ActorContext;
+import akka.actor.typed.javadsl.Behaviors;
+import akka.actor.typed.javadsl.Receive;
+
+public class FakCont extends AbstractBehavior<FakCont.Message> {
+
+    private final int val;
+    private final ActorRef<Message> cust;
+
+    public interface Message {};
+
+    public record FakContMessage(int arg) implements Message {  }
+
+    public static Behavior<Message> create(int val, ActorRef<Message> cust) {
+        return Behaviors.setup(context -> new FakCont(context, val, cust));
+    }
+
+
+
+    private FakCont(ActorContext<Message> context, int val, ActorRef<Message> cust) {
+        super(context);
+        this.val = val;
+        this.cust = cust;
+    }
+
+    @Override
+    public Receive<Message> createReceive() {
+        return newReceiveBuilder()
+                .onMessage(FakContMessage.class, this::onFakContMessage)
+                .build();
+    }
+
+    private Behavior<Message> onFakContMessage(FakContMessage msg) {
+        this.cust.tell(new FakContMessage(this.val * msg.arg));
+        return this;
+    }
+}