4 files changed, 31 insertions, 9 deletions

diff --git a/subprojects/frontend/src/xtext/ModelGenerationService.ts b/subprojects/frontend/src/xtext/ModelGenerationService.ts
index 1e9f837a..29a70623 100644
--- a/subprojects/frontend/src/xtext/ModelGenerationService.ts
+++ b/subprojects/frontend/src/xtext/ModelGenerationService.ts
@@ -4,12 +4,18 @@
  * SPDX-License-Identifier: EPL-2.0
  */
 
+import type { Transaction } from '@codemirror/state';
+
 import type EditorStore from '../editor/EditorStore';
 
 import type UpdateService from './UpdateService';
 import { ModelGenerationResult } from './xtextServiceResults';
 
+const INITIAL_RANDOM_SEED = 1;
+
 export default class ModelGenerationService {
+  private nextRandomSeed = INITIAL_RANDOM_SEED;
+
   constructor(
     private readonly store: EditorStore,
     private readonly updateService: UpdateService,
@@ -26,14 +32,24 @@ export default class ModelGenerationService {
     }
   }
 
+  onTransaction(transaction: Transaction): void {
+    if (transaction.docChanged) {
+      this.resetRandomSeed();
+    }
+  }
+
   onDisconnect(): void {
     this.store.modelGenerationCancelled();
+    this.resetRandomSeed();
   }
 
-  async start(): Promise<void> {
-    const result = await this.updateService.startModelGeneration();
+  async start(randomSeed?: number): Promise<void> {
+    const randomSeedOrNext = randomSeed ?? this.nextRandomSeed;
+    this.nextRandomSeed = randomSeedOrNext + 1;
+    const result =
+      await this.updateService.startModelGeneration(randomSeedOrNext);
     if (!result.cancelled) {
-      this.store.addGeneratedModel(result.data.uuid);
+      this.store.addGeneratedModel(result.data.uuid, randomSeedOrNext);
     }
   }
 
@@ -43,4 +59,8 @@ export default class ModelGenerationService {
       this.store.modelGenerationCancelled();
     }
   }
+
+  private resetRandomSeed() {
+    this.nextRandomSeed = INITIAL_RANDOM_SEED;
+  }
 }
diff --git a/subprojects/frontend/src/xtext/UpdateService.ts b/subprojects/frontend/src/xtext/UpdateService.ts
index d1246d5e..70e79764 100644
--- a/subprojects/frontend/src/xtext/UpdateService.ts
+++ b/subprojects/frontend/src/xtext/UpdateService.ts
@@ -343,9 +343,9 @@ export default class UpdateService {
     return { cancelled: false, data: parsedOccurrencesResult };
   }
 
-  async startModelGeneration(): Promise<
-    CancellableResult<ModelGenerationStartedResult>
-  > {
+  async startModelGeneration(
+    randomSeed: number,
+  ): Promise<CancellableResult<ModelGenerationStartedResult>> {
     try {
       await this.updateOrThrow();
     } catch (error) {
@@ -360,6 +360,7 @@ export default class UpdateService {
       serviceType: 'modelGeneration',
       requiredStateId: this.xtextStateId,
       start: true,
+      randomSeed,
     });
     if (isConflictResult(data)) {
       return { cancelled: true };
diff --git a/subprojects/frontend/src/xtext/XtextClient.ts b/subprojects/frontend/src/xtext/XtextClient.ts
index 4df4f57a..7486d737 100644
--- a/subprojects/frontend/src/xtext/XtextClient.ts
+++ b/subprojects/frontend/src/xtext/XtextClient.ts
@@ -99,6 +99,7 @@ export default class XtextClient {
     this.contentAssistService.onTransaction(transaction);
     this.updateService.onTransaction(transaction);
     this.occurrencesService.onTransaction(transaction);
+    this.modelGenerationService.onTransaction(transaction);
   }
 
   private onPush(
@@ -150,8 +151,8 @@ export default class XtextClient {
     return this.contentAssistService.contentAssist(context);
   }
 
-  startModelGeneration(): Promise<void> {
-    return this.modelGenerationService.start();
+  startModelGeneration(randomSeed?: number): Promise<void> {
+    return this.modelGenerationService.start(randomSeed);
   }
 
   cancelModelGeneration(): Promise<void> {
diff --git a/subprojects/frontend/src/xtext/XtextWebSocketClient.ts b/subprojects/frontend/src/xtext/XtextWebSocketClient.ts
index bb84223c..280ac875 100644
--- a/subprojects/frontend/src/xtext/XtextWebSocketClient.ts
+++ b/subprojects/frontend/src/xtext/XtextWebSocketClient.ts
@@ -204,7 +204,7 @@ export default class XtextWebSocketClient {
 
   get state() {
     this.stateAtom.reportObserved();
-    return this.interpreter.state;
+    return this.interpreter.getSnapshot();
   }
 
   get opening(): boolean {