feat: further work on stores

src/stores.ts

@@ -1,5 +1,6 @@
 import z from "zod";
-import type { StoreType } from "./entities/Stores";
+import { Store, type StoreType } from "./entities/Stores";
+import type { User } from "./entities/User";
 
 export const locationStore = z.object({
 	lat: z.number().min(-90).max(90),
@@ -42,3 +43,46 @@ export const storeTypes: Record<StoreType, z.ZodSchema> = {
 	vehicle: vehicleStore,
 	route: routeStore,
 };
+
+export const SyncPayload = z.object({
+	changes: z.array(z.object({
+		id: z.uuid(),
+		operation: z.enum(["create", "update", "delete"]),
+		data: z.string(),
+		modified_at: z.string().refine(val => !isNaN(Date.parse(val)), { message: "Invalid date" })
+	})),
+	stores: z.array(z.object({
+		id: z.uuid(),
+		modified_at: z.string().refine(val => !isNaN(Date.parse(val)), { message: "Invalid date" })
+	}))
+})
+
+export type SyncPayload = z.infer<typeof SyncPayload>;
+
+export async function sync(payload: SyncPayload, user: User) {
+	const changes: Store[] = [];
+	// Apply changes from client
+	for(const change of payload.changes) {
+		const store = await Store.findOneBy({ id: change.id });
+		if(!store) continue;
+		if(store.user.id !== user.id) {
+			// Not the owner of this store
+			changes.push(store); // Send back the store to the client to overwrite their changes
+			continue;
+		}
+		store.data = change.data;
+		store.modified_at = new Date(change.modified_at);
+		await store.save();
+	}
+
+	// Find stores that are out of date on the client
+	const allStores = await Store.findBy({ user: { id: user.id } }); // TODO: include friends' public stores, TODO: use SQL query to only get modified stores
+	for(const store of allStores) {
+		const clientStore = payload.stores.find(s => s.id === store.id);
+		if(!clientStore || new Date(clientStore.modified_at) < store.modified_at) {
+			changes.push(store); // Client doesn't have this store or it's out of date
+		}
+	}
+	
+	return { changes };
+}