From a546d257f35408c90f7b5f5f4d6fca8d7a372b33 Mon Sep 17 00:00:00 2001
From: Johan Maasing <johan@zoom.nu>
Date: Sat, 19 Apr 2025 07:08:06 +0200
Subject: [PATCH] Grammar for states and transitions

---
 .../nu/zoom/dsl/ast/ParseTreeTransformer.java | 14 -----
 .../dsl/ast/StatesVisitorTransformer.java     | 56 ++++++++++++++++++-
 .../java/nu/zoom/dsl/cli/EndpointsCLI.java    |  5 +-
 states-templates/nodes.md.ftl                 | 29 ++++++++++
 test01.states                                 |  4 ++
 5 files changed, 88 insertions(+), 20 deletions(-)
 delete mode 100644 parser/src/main/java/nu/zoom/dsl/ast/ParseTreeTransformer.java
 create mode 100644 states-templates/nodes.md.ftl
 create mode 100644 test01.states

diff --git a/parser/src/main/java/nu/zoom/dsl/ast/ParseTreeTransformer.java b/parser/src/main/java/nu/zoom/dsl/ast/ParseTreeTransformer.java
deleted file mode 100644
index d9ef9f9..0000000
--- a/parser/src/main/java/nu/zoom/dsl/ast/ParseTreeTransformer.java
+++ /dev/null
@@ -1,14 +0,0 @@
-package nu.zoom.dsl.ast;
-
-import java.util.List;
-import java.util.Map;
-
-public interface ParseTreeTransformer {
-
-    List<EndpointNode> getEndpoints();
-
-    Map<String,String> getConfig();
-
-    List<TypeNode> getDataTypes();
-
-}
diff --git a/parser/src/main/java/nu/zoom/dsl/ast/StatesVisitorTransformer.java b/parser/src/main/java/nu/zoom/dsl/ast/StatesVisitorTransformer.java
index 4fd3c97..e1360a7 100644
--- a/parser/src/main/java/nu/zoom/dsl/ast/StatesVisitorTransformer.java
+++ b/parser/src/main/java/nu/zoom/dsl/ast/StatesVisitorTransformer.java
@@ -2,8 +2,10 @@ package nu.zoom.dsl.ast;
 
 import nu.zoom.dsl.parser.StatesBaseVisitor;
 import nu.zoom.dsl.parser.StatesParser;
+import org.antlr.v4.runtime.tree.TerminalNode;
 
 import java.util.*;
+import java.util.stream.Stream;
 
 public class StatesVisitorTransformer extends StatesBaseVisitor<StatesParser.DocumentContext> {
     private final HashMap<String,String> config = new HashMap<>();
@@ -29,9 +31,30 @@ public class StatesVisitorTransformer extends StatesBaseVisitor<StatesParser.Doc
         return super.visitState(ctx);
     }
 
+    @Override
+    public StatesParser.DocumentContext visitMessage(StatesParser.MessageContext ctx) {
+        String messageName = ctx.typeName().IDENTIFIER().getText() ;
+        List<FieldNode> fields = extractFields(ctx.typeDeclaration()) ;
+        this.messageTypes.add(new TypeNode(messageName, fields));
+        return super.visitMessage(ctx);
+    }
+
+    @Override
+    public StatesParser.DocumentContext visitConfigitem(StatesParser.ConfigitemContext ctx) {
+        String configKey = ctx.configkey().IDENTIFIER().getText();
+        String configValue = getText(ctx.configvalue().IDENTIFIER(), ctx.configvalue().VALUE());
+        this.config.put(configKey, configValue);
+        return super.visitConfigitem(ctx);
+    }
+
     public Set<StateNode> getStates() {
-        // TODO: Calculate state nodes from this.transitions
-        return Set.of();
+        HashSet<StateNode> states = new HashSet<>();
+        this.transitions.forEach((state,v)->{
+            HashSet<TransitionNode> transitionNodes = new HashSet<>();
+            v.forEach((to, message) -> transitionNodes.add(new TransitionNode(message, to)));
+            states.add(new StateNode(state, "", transitionNodes)) ;
+        }) ;
+        return states ;
     }
 
     public Map<String,String> getConfig() {
@@ -40,10 +63,28 @@ public class StatesVisitorTransformer extends StatesBaseVisitor<StatesParser.Doc
 
     public Set<TypeNode> getTypes() {
         // TODO calculate data types from NodeTypes and MessageTypes with duplicate check.
-        return Set.of() ;
+        HashMap<String, TypeNode> typeNodes = new HashMap<>();
+        this.nodeTypes.forEach(typeNode -> {
+            if (typeNodes.containsKey(typeNode.name())) {
+                throw new RuntimeException("Duplicate type name: " + typeNode.name());
+            } else {
+                typeNodes.put(typeNode.name(), typeNode);
+            }
+        }) ;
+        this.messageTypes.forEach(typeNode -> {
+            if (typeNodes.containsKey(typeNode.name())) {
+                throw new RuntimeException("Duplicate type name: " + typeNode.name());
+            } else {
+                typeNodes.put(typeNode.name(), typeNode);
+            }
+        }) ;
+        return Set.of(typeNodes.values().toArray(new TypeNode[0])) ;
     }
 
     private List<FieldNode> extractFields(StatesParser.TypeDeclarationContext declaration) {
+        if (declaration == null) {
+            return Collections.emptyList();
+        }
         return declaration
                 .typeField()
                 .stream()
@@ -53,4 +94,13 @@ public class StatesVisitorTransformer extends StatesBaseVisitor<StatesParser.Doc
                 )
                 .toList();
     }
+
+    // Concatenate the text from two terminal nodes. Useful for contexts that are either an identifier or a value,
+    // and you just want the text from whichever is not null.
+    private String getText(TerminalNode identifier, TerminalNode value) {
+        return
+                ((identifier != null) ? identifier.getText() : "") +
+                        ((value != null) ? value.getText() : "");
+    }
+
 }
diff --git a/parser/src/main/java/nu/zoom/dsl/cli/EndpointsCLI.java b/parser/src/main/java/nu/zoom/dsl/cli/EndpointsCLI.java
index e5c8eda..724d9b4 100644
--- a/parser/src/main/java/nu/zoom/dsl/cli/EndpointsCLI.java
+++ b/parser/src/main/java/nu/zoom/dsl/cli/EndpointsCLI.java
@@ -26,7 +26,6 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.List;
-import java.util.Optional;
 import java.util.concurrent.Callable;
 
 @Command(
@@ -35,7 +34,7 @@ import java.util.concurrent.Callable;
 	description = "Generate source code from an endpoints specification file."
 )
 public class EndpointsCLI implements Callable<Integer> {
-	public static enum ParserType {
+	public enum ParserType {
 		Endpoints,
 		States
 	}
@@ -71,7 +70,7 @@ public class EndpointsCLI implements Callable<Integer> {
 			validateOutputDirectory();
 			verbose("Parsing: " + file.toAbsolutePath());
 			if (parser == null) {
-				if (file.getFileName().endsWith(".states")) {
+				if (file.getFileName().toString().endsWith(".states")) {
 					parser = ParserType.States;
 				}
 			}
diff --git a/states-templates/nodes.md.ftl b/states-templates/nodes.md.ftl
new file mode 100644
index 0000000..89a5603
--- /dev/null
+++ b/states-templates/nodes.md.ftl
@@ -0,0 +1,29 @@
+```
+Copyright 2025 "Johan Maasing" <johan@zoom.nu>
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+```
+
+# The nodes
+
+```mermaid
+---
+title: ${config.title}
+---
+stateDiagram-v2
+<#list states as state>
+    <#list state.transitions as transition>
+    ${state.name} --> ${transition.toState} : ${transition.message}
+    </#list>
+</#list>
+```
\ No newline at end of file
diff --git a/test01.states b/test01.states
new file mode 100644
index 0000000..d1f78a9
--- /dev/null
+++ b/test01.states
@@ -0,0 +1,4 @@
+{ title: SomeNodes }
+start(s:S) -> middle: message(foo:bar),
+middle -> middle: selfmessage,
+middle -> end: endmessage(bar:baz)
\ No newline at end of file