dot has colors now

src/main/java/click/kamil/springstatemachineexporter/ast/out/Dot.java

@@ -10,18 +10,17 @@ public class Dot implements StateMachineExporter {
 
     @Override
     public String export(List<Transition> transitions,
-                                     Set<String> startStates,
+                         Set<String> startStates,
-                                     Set<String> endStates,
+                         Set<String> endStates,
-                                     boolean useLambdaGuards) {
+                         boolean useLambdaGuards) {
+
         StringBuilder sb = new StringBuilder();
         sb.append("digraph stateMachine {\n");
         sb.append("  rankdir=LR;\n");
         sb.append("  node [shape=circle, style=filled, fillcolor=lightgray];\n\n");
 
-        // 1. Fake start node
         sb.append("  start [shape=point, label=\"\"];\n");
 
-        // 2. Find states with choice transitions
         Set<String> statesWithChoice = new HashSet<>();
         for (Transition t : transitions) {
             if ("withChoice".equals(t.getType())) {
@@ -31,18 +30,20 @@ public class Dot implements StateMachineExporter {
             }
         }
 
-        // 3. Declare normal states and choice pseudostates
         Set<String> allStates = new HashSet<>();
         for (Transition t : transitions) {
             if (t.getSourceStates() != null) {
-                for (String s : t.getSourceStates()) allStates.add(simplify(s));
+                for (String s : t.getSourceStates()) {
+                    allStates.add(simplify(s));
+                }
             }
             if (t.getTargetStates() != null) {
-                for (String tgt : t.getTargetStates()) allStates.add(simplify(tgt));
+                for (String tgt : t.getTargetStates()) {
+                    allStates.add(simplify(tgt));
+                }
             }
         }
 
-        // Print all normal states (except choice pseudostates for now)
         for (String state : allStates) {
             if (!statesWithChoice.contains(state + "_choice")) {
                 String shape = endStates.contains(state) ? "doublecircle" : "circle";
@@ -50,46 +51,40 @@ public class Dot implements StateMachineExporter {
                         .append(" [shape=").append(shape).append(", fillcolor=lightgray];\n");
             }
         }
-        sb.append("\n");
 
-        // Declare choice pseudostates as diamonds
         for (String state : statesWithChoice) {
             String choiceNode = state + "_choice";
             sb.append("  ").append(choiceNode)
                     .append(" [shape=diamond, label=\"\", fillcolor=lightyellow];\n");
         }
+
         sb.append("\n");
 
-        // 4. Connect start node(s) to start states
         for (String start : startStates) {
             sb.append("  start -> ").append(simplify(start)).append(";\n");
         }
+
         sb.append("\n");
 
-        // 5. Connect normal states to their choice pseudostates
         for (String state : statesWithChoice) {
             String choiceNode = state + "_choice";
             sb.append("  ").append(state).append(" -> ").append(choiceNode).append(";\n");
         }
+
         sb.append("\n");
 
-        // 6. Transitions: reroute withChoice transitions via choice pseudostate
         for (Transition t : transitions) {
             if (t.getSourceStates() == null || t.getSourceStates().isEmpty()) continue;
 
             boolean allowNoTarget = "withJoin".equals(t.getType()) || "withFork".equals(t.getType());
+            List<String> targets = t.getTargetStates();
 
-            List<String> targets;
+            if (targets == null || targets.isEmpty()) {
-            if (t.getTargetStates() == null || t.getTargetStates().isEmpty()) {
                 if (!allowNoTarget) {
-                    // self-loop: targets = sources
+                    targets = t.getSourceStates(); // self-loop
-                    targets = t.getSourceStates();
                 } else {
-                    // withJoin/withFork with no targets: skip
                     continue;
                 }
-            } else {
-                targets = t.getTargetStates();
             }
 
             for (String rawSource : t.getSourceStates()) {
@@ -103,54 +98,97 @@ public class Dot implements StateMachineExporter {
                         edgeSource = source + "_choice";
                     }
 
-                    // Prepare guard text
+                    // Guard
                     String guardText = "";
                     if (t.getGuard() != null && !t.getGuard().isBlank()) {
                         if (useLambdaGuards && t.isLambdaGuard()) {
-                            guardText = "lambda";
+                            guardText = "λ";
                         } else {
-                            guardText = t.getGuard().replaceAll("[\\n\\r]+", " ").replaceAll("\\s{2,}", " ").trim();
+                            guardText = escapeDotString(
+                                    t.getGuard().replaceAll("[\\n\\r]+", " ")
+                                            .replaceAll("\\s{2,}", " ")
+                                            .trim()
+                            );
                         }
                     }
 
-                    // Prepare actions text
+                    // Actions
                     String actionsText = "";
                     if (t.getActions() != null && !t.getActions().isEmpty()) {
                         StringBuilder actionBuilder = new StringBuilder();
                         for (int i = 0; i < t.getActions().size(); i++) {
                             if (i > 0) actionBuilder.append(", ");
                             String action = t.getActions().get(i);
-                            boolean isLambda = t.getIsLambdaActions().get(i);
+                            boolean isLambda = i < t.getIsLambdaActions().size() && t.getIsLambdaActions().get(i);
                             if (useLambdaGuards && isLambda) {
-                                actionBuilder.append("lambda");
+                                actionBuilder.append("λ");
                             } else {
-                                actionBuilder.append(action);
+                                actionBuilder.append(escapeDotString(action));
                             }
                         }
                         actionsText = actionBuilder.toString();
                     }
 
-                    // Build label with event, guard, and actions
+                    // Event and label
                     StringBuilder label = new StringBuilder();
                     if (t.getEvent() != null && !t.getEvent().isBlank()) {
-                        label.append(simplify(t.getEvent()));
+                        label.append(escapeDotString(simplify(t.getEvent())));
                     }
+
                     if (!guardText.isBlank()) {
                         if (!label.isEmpty()) label.append(" ");
                         label.append("[").append(guardText).append("]");
                     }
+
                     if (!actionsText.isBlank()) {
                         if (!label.isEmpty()) label.append(" / ");
                         label.append(actionsText);
                     }
 
-                    // Add order info for choice/junction transitions
                     if (("withChoice".equals(t.getType()) || "withJunction".equals(t.getType())) && t.getOrder() != null) {
                         if (!label.isEmpty()) label.append(" ");
                         label.append("(order=").append(t.getOrder()).append(")");
                     }
 
-                    String edgeLabel = !label.isEmpty() ? " [label=\"" + label.toString() + "\"]" : "";
+                    // Build edge attributes
+                    StringBuilder edgeAttributes = new StringBuilder();
+                    if (!label.isEmpty()) {
+                        appendEdgeAttr(edgeAttributes, "label", label.toString());
+                    }
+
+                    switch (t.getType()) {
+                        case "withInternal":
+                            appendEdgeAttr(edgeAttributes, "style", "dashed");
+                            appendEdgeAttr(edgeAttributes, "color", "gray");
+                            break;
+                        case "withLocal":
+                            appendEdgeAttr(edgeAttributes, "style", "dotted");
+                            appendEdgeAttr(edgeAttributes, "color", "darkgray");
+                            break;
+                        case "withChoice":
+                            appendEdgeAttr(edgeAttributes, "style", "solid");
+                            appendEdgeAttr(edgeAttributes, "color", "blue");
+                            break;
+                        case "withJunction":
+                            appendEdgeAttr(edgeAttributes, "style", "dotted");
+                            appendEdgeAttr(edgeAttributes, "color", "purple");
+                            break;
+                        case "withFork":
+                            appendEdgeAttr(edgeAttributes, "style", "bold");
+                            appendEdgeAttr(edgeAttributes, "color", "green");
+                            break;
+                        case "withJoin":
+                            appendEdgeAttr(edgeAttributes, "style", "bold");
+                            appendEdgeAttr(edgeAttributes, "color", "darkorange");
+                            break;
+                        case "withExternal":
+                        default:
+                            appendEdgeAttr(edgeAttributes, "style", "solid");
+                            appendEdgeAttr(edgeAttributes, "color", "black");
+                            break;
+                    }
+
+                    String edgeLabel = !edgeAttributes.isEmpty() ? " [" + edgeAttributes + "]" : "";
 
                     sb.append("  ").append(edgeSource).append(" -> ").append(target).append(edgeLabel).append(";\n");
                 }
@@ -165,4 +203,15 @@ public class Dot implements StateMachineExporter {
     public String getFileExtension() {
         return ".dot";
     }
+
+    private String escapeDotString(String input) {
+        if (input == null) return "";
+        return input.replace("\\", "\\\\")
+                .replace("\"", "\\\"");
+    }
+
+    private void appendEdgeAttr(StringBuilder sb, String key, String value) {
+        if (!sb.isEmpty()) sb.append(", ");
+        sb.append(key).append("=\"").append(value).append("\"");
+    }
 }