From 52e7485434933d7133f93ecad015b142e1a9a3b8 Mon Sep 17 00:00:00 2001
From: Nico Rehwaldt <git_nikku@nixis.de>
Date: Thu, 14 Dec 2023 23:07:48 +0100
Subject: [PATCH] WIP

---
 lib/simulator/Simulator.js                 | 67 ++++++++++++++++++----
 lib/simulator/behaviors/ProcessBehavior.js | 29 ++++++++--
 lib/simulator/util/ModelUtil.js            | 13 +++++
 3 files changed, 92 insertions(+), 17 deletions(-)

diff --git a/lib/simulator/Simulator.js b/lib/simulator/Simulator.js
index b268fe2f..398aa9dc 100644
--- a/lib/simulator/Simulator.js
+++ b/lib/simulator/Simulator.js
@@ -17,12 +17,27 @@ import {
   is,
   isAny,
   isBoundaryEvent,
+  isCatchEvent,
   isCompensationEvent,
   isEventSubProcess,
   isInterrupting,
-  isStartEvent
+  isStartEvent,
+  isStartNode
 } from './util/ModelUtil';
 
+/**
+ * @typedef { any } DiagramElement
+ *
+ * @typedef { {
+ *   element: DiagramElement,
+ *   interrupting: boolean,
+ *   boundary: boolean,
+ *   iref?: string,
+ *   ref: DiagramElement,
+ *   persistent?: boolean,
+ *   type: string
+ * } } SimulatorEvent
+ */
 
 export default function Simulator(injector, eventBus, elementRegistry) {
 
@@ -148,7 +163,9 @@ export default function Simulator(injector, eventBus, elementRegistry) {
         scope
       });
 
-      scopeChanged(parentScope);
+      if (scope.parent) {
+        scopeChanged(scope.parent);
+      }
     });
 
     return scope;
@@ -290,6 +307,11 @@ export default function Simulator(injector, eventBus, elementRegistry) {
     return null;
   }
 
+  /**
+   * @param { any } element
+   *
+   * @return {SimulatorEvent}
+   */
   function getEvent(element) {
 
     // do not double-return element
@@ -638,21 +660,44 @@ export default function Simulator(injector, eventBus, elementRegistry) {
 
       rootScopes.push(scope);
 
-      const startEvents = element.children.filter(isStartEvent);
+      const startNodes = element.children.filter(isStartNode);
+
+      const noneStarts = [];
 
-      for (const startEvent of startEvents) {
+      for (const startNode of startNodes) {
 
         const event = {
-          ...getEvent(startEvent),
+          ...getEvent(startNode),
           interrupting: false
         };
 
-        // start events can always be triggered
-        subscribe(scope, event, initiator => signal({
-          element,
-          startEvent,
-          initiator
-        }));
+        console.log(event);
+
+        if (isCatchEvent(startNode) || event.type === 'none') {
+          noneStarts.push([ event, startNode ]);
+        } else {
+
+          // start events can always be triggered
+          subscribe(scope, event, initiator => signal({
+            element,
+            startNodes: [ startNode ],
+            initiator
+          }));
+        }
+      }
+
+      if (noneStarts.length) {
+        const startNodes = noneStarts.map(([ _, node ]) => node);
+
+        for (const [ event ] of noneStarts) {
+
+          // start events can always be triggered
+          subscribe(scope, event, initiator => signal({
+            element,
+            startNodes,
+            initiator
+          }));
+        }
       }
     });
 
diff --git a/lib/simulator/behaviors/ProcessBehavior.js b/lib/simulator/behaviors/ProcessBehavior.js
index debb2844..fedc3746 100644
--- a/lib/simulator/behaviors/ProcessBehavior.js
+++ b/lib/simulator/behaviors/ProcessBehavior.js
@@ -1,3 +1,8 @@
+import {
+  isStartEvent
+} from '../util/ModelUtil';
+
+
 export default function ProcessBehavior(
     simulator,
     scopeBehavior) {
@@ -13,17 +18,29 @@ ProcessBehavior.prototype.signal = function(context) {
 
   const {
     startEvent,
+    startNodes = startEvent ? [ startEvent ] : [],
     scope
   } = context;
 
-  if (!startEvent) {
-    throw new Error('missing <startEvent>');
+  if (!startNodes.length) {
+    throw new Error('missing <startNodes>');
+  }
+
+  for (const startNode of startNodes) {
+
+    if (isStartEvent(startNode)) {
+      this._simulator.signal({
+        element: startNode,
+        parentScope: scope
+      });
+    } else {
+      this._simulator.enter({
+        element: startNode,
+        scope
+      });
+    }
   }
 
-  this._simulator.signal({
-    element: startEvent,
-    parentScope: scope
-  });
 };
 
 ProcessBehavior.prototype.exit = function(context) {
diff --git a/lib/simulator/util/ModelUtil.js b/lib/simulator/util/ModelUtil.js
index 969d1d27..81b160a8 100644
--- a/lib/simulator/util/ModelUtil.js
+++ b/lib/simulator/util/ModelUtil.js
@@ -49,6 +49,19 @@ export function isBoundaryEvent(element) {
   return is(element, 'bpmn:BoundaryEvent') && !isLabel(element);
 }
 
+export function isImplicitStart(element) {
+  return (
+    !isBoundaryEvent(element) &&
+    !isEventSubProcess(element) &&
+    !isSequenceFlow(element) &&
+    element.incoming.length === 0
+  );
+}
+
+export function isStartNode(element) {
+  return isStartEvent(element) || isImplicitStart(element);
+}
+
 export function isStartEvent(element) {
   return is(element, 'bpmn:StartEvent') && !isLabel(element);
 }