[Init] Initial commit - NetMesh terminal manager

application/state/textEditorSaveCoordinator.ts

@@ -0,0 +1,90 @@
+export interface TextEditorSaveCoordinator {
+  save(content: string): Promise<boolean>;
+  isSaving(): boolean;
+  reset(): void;
+}
+
+export interface TextEditorSaveCoordinatorOptions {
+  onSave: (content: string) => Promise<void>;
+  onSaveStart?: (content: string) => void;
+  onSaveSuccess?: (content: string) => void;
+  onSaveError?: (error: unknown) => void;
+  onSavingChange?: (saving: boolean) => void;
+}
+
+interface InFlightSave {
+  content: string;
+  promise: Promise<boolean>;
+}
+
+export const createTextEditorSaveCoordinator = (
+  options: TextEditorSaveCoordinatorOptions,
+): TextEditorSaveCoordinator => {
+  let inFlight: InFlightSave | null = null;
+  let generation = 0;
+
+  const notifySavingChange = () => {
+    options.onSavingChange?.(inFlight !== null);
+  };
+
+  const startSave = (content: string): Promise<boolean> => {
+    const saveGeneration = generation;
+    options.onSaveStart?.(content);
+
+    const promise = (async () => {
+      try {
+        await options.onSave(content);
+        if (saveGeneration !== generation) {
+          return false;
+        }
+        if (saveGeneration === generation) {
+          options.onSaveSuccess?.(content);
+        }
+        return true;
+      } catch (error) {
+        if (saveGeneration !== generation) {
+          return false;
+        }
+        if (saveGeneration === generation) {
+          options.onSaveError?.(error);
+        }
+        return false;
+      }
+    })();
+
+    const entry = { content, promise };
+    inFlight = entry;
+    notifySavingChange();
+    void promise.finally(() => {
+      if (inFlight === entry) {
+        inFlight = null;
+        notifySavingChange();
+      }
+    });
+    return promise;
+  };
+
+  const save = async (content: string): Promise<boolean> => {
+    const current = inFlight;
+    if (current) {
+      const waitGeneration = generation;
+      const ok = await current.promise;
+      if (waitGeneration !== generation) return false;
+      if (!ok || current.content === content) return ok;
+      return save(content);
+    }
+    return startSave(content);
+  };
+
+  return {
+    save,
+    isSaving: () => inFlight !== null,
+    reset: () => {
+      generation += 1;
+      if (inFlight) {
+        inFlight = null;
+        notifySavingChange();
+      }
+    },
+  };
+};