Integrate Canvas V2 subgraphs, editable edges and AI runs

src/lib/canvas-sync.ts

@@ -1,3 +1,4 @@
+import { CANVAS_ACCEPT } from "./canvas-v2.ts";
 import { decodeCanvas, type CanvasDocument } from "./canvas.ts";
 
 export type CanvasSnapshot = { version: number; document: CanvasDocument };
@@ -23,6 +24,7 @@ export class CanvasSync {
   version: number;
   saved: string;
   error = "";
+  document: CanvasDocument;
   private pending: CanvasDocument | null = null;
   private running: Promise<void> | null = null;
   private request: CanvasRequest;
@@ -31,6 +33,7 @@ export class CanvasSync {
   constructor(request: CanvasRequest, path: string, initial: CanvasSnapshot, notify: (state: SyncState) => void) {
     this.request = request; this.path = path; this.version = initial.version;
     this.saved = canvasFingerprint(initial.document); this.notify = notify;
+    this.document = initial.document;
   }
   enqueue(document: CanvasDocument): Promise<void> {
     this.pending = document;
@@ -39,6 +42,12 @@ export class CanvasSync {
     return this.running;
   }
   retry() { this.error = ""; return this.pending ? this.enqueue(this.pending) : Promise.resolve(); }
+  async settled() { await this.running; }
+  adopt(snapshot: CanvasSnapshot) {
+    if (this.running) throw new Error("canvas_busy");
+    this.pending = null; this.error = ""; this.version = snapshot.version; this.document = snapshot.document;
+    this.saved = canvasFingerprint(snapshot.document); this.notify({ status: "saved", version: this.version });
+  }
   private async drain() {
     while (this.pending) {
       const document = this.pending; this.pending = null;
@@ -48,9 +57,10 @@ export class CanvasSync {
         if (fingerprint === this.saved) { this.notify({ status: "saved", version: this.version }); continue; }
         const body = JSON.stringify({ document: canvasPayload(document) });
         if (new TextEncoder().encode(body).length > 5 * 1024 * 1024) throw new Error("canvas_too_large");
-        const result = await this.request<{ version: number }>(this.path, { method: "PATCH", headers: { "If-Match": `"${this.version}"` }, body });
+        const result = await this.request<{ version: number }>(this.path, { method: "PATCH", headers: { Accept: CANVAS_ACCEPT, "If-Match": `"${this.version}"` }, body });
         if (!Number.isSafeInteger(result?.version) || result.version !== this.version + 1) throw new Error("invalid_canvas_snapshot");
         this.version = result.version; this.saved = fingerprint;
+        this.document = document;
         this.notify({ status: "saved", version: this.version });
       } catch (error) {
         this.pending ||= document;
@@ -75,3 +85,8 @@ export function readLocalRecovery(storage: Pick<Storage, "getItem">, key: string
   const doc = decodeCanvas(legacy);
   return !snapshot || canvasFingerprint(doc) !== canvasFingerprint(snapshot.document) ? doc : null;
 }
+export function canRestoreCanvasDraft(draft: CanvasDocument, remote: CanvasDocument) {
+  if (draft.schema_version < remote.schema_version) return false;
+  const relations = (document: CanvasDocument) => document.nodes.filter((node) => node.data.subgraph).map((node) => ({ id: node.id, subgraph: node.data.subgraph, ports: node.data.ports || [] })).sort((a, b) => a.id.localeCompare(b.id));
+  return JSON.stringify(relations(draft)) === JSON.stringify(relations(remote));
+}