feat: add snjs package

packages/snjs/lib/Services/Sync/Account/ResponseResolver.ts

@@ -0,0 +1,86 @@
+import {
+  ImmutablePayloadCollection,
+  HistoryMap,
+  DeltaRemoteRetrieved,
+  DeltaRemoteSaved,
+  DeltaRemoteDataConflicts,
+  FullyFormedPayloadInterface,
+  ServerSyncPushContextualPayload,
+  ServerSyncSavedContextualPayload,
+  DeltaRemoteUuidConflicts,
+  DeltaRemoteRejected,
+  DeltaEmit,
+} from '@standardnotes/models'
+
+type PayloadSet = {
+  retrievedPayloads: FullyFormedPayloadInterface[]
+  savedPayloads: ServerSyncSavedContextualPayload[]
+  uuidConflictPayloads: FullyFormedPayloadInterface[]
+  dataConflictPayloads: FullyFormedPayloadInterface[]
+  rejectedPayloads: FullyFormedPayloadInterface[]
+}
+
+/**
+ * Given a remote sync response, the resolver applies the incoming changes on top
+ * of the current base state, and returns what the new global state should look like.
+ * The response resolver is purely functional and does not modify global state, but instead
+ * offers the 'recommended' new global state given a sync response and a current base state.
+ */
+export class ServerSyncResponseResolver {
+  constructor(
+    private payloadSet: PayloadSet,
+    private baseCollection: ImmutablePayloadCollection<FullyFormedPayloadInterface>,
+    private payloadsSavedOrSaving: ServerSyncPushContextualPayload[],
+    private historyMap: HistoryMap,
+  ) {}
+
+  public result(): DeltaEmit[] {
+    const emits: DeltaEmit[] = []
+
+    emits.push(this.processRetrievedPayloads())
+    emits.push(this.processSavedPayloads())
+    emits.push(this.processUuidConflictPayloads())
+    emits.push(this.processDataConflictPayloads())
+    emits.push(this.processRejectedPayloads())
+
+    return emits
+  }
+
+  private processSavedPayloads(): DeltaEmit {
+    const delta = new DeltaRemoteSaved(this.baseCollection, this.payloadSet.savedPayloads)
+
+    return delta.result()
+  }
+
+  private processRetrievedPayloads(): DeltaEmit {
+    const collection = ImmutablePayloadCollection.WithPayloads(this.payloadSet.retrievedPayloads)
+
+    const delta = new DeltaRemoteRetrieved(this.baseCollection, collection, this.payloadsSavedOrSaving, this.historyMap)
+
+    return delta.result()
+  }
+
+  private processDataConflictPayloads(): DeltaEmit {
+    const collection = ImmutablePayloadCollection.WithPayloads(this.payloadSet.dataConflictPayloads)
+
+    const delta = new DeltaRemoteDataConflicts(this.baseCollection, collection, this.historyMap)
+
+    return delta.result()
+  }
+
+  private processUuidConflictPayloads(): DeltaEmit {
+    const collection = ImmutablePayloadCollection.WithPayloads(this.payloadSet.uuidConflictPayloads)
+
+    const delta = new DeltaRemoteUuidConflicts(this.baseCollection, collection)
+
+    return delta.result()
+  }
+
+  private processRejectedPayloads(): DeltaEmit {
+    const collection = ImmutablePayloadCollection.WithPayloads(this.payloadSet.rejectedPayloads)
+
+    const delta = new DeltaRemoteRejected(this.baseCollection, collection)
+
+    return delta.result()
+  }
+}