feat: Add reordering to starred documents (#2953)

* draft

* reordering

* JIT Index stars on first load

* test

* Remove unused code on client

* small unrefactor

server/utils/indexing.ts

@@ -0,0 +1,82 @@
+import fractionalIndex from "fractional-index";
+import naturalSort from "@shared/utils/naturalSort";
+import { Collection, Document, Star } from "@server/models";
+
+export async function collectionIndexing(
+  teamId: string
+): Promise<{ [id: string]: string }> {
+  const collections = await Collection.findAll({
+    where: {
+      teamId,
+      // no point in maintaining index of deleted collections.
+      deletedAt: null,
+    },
+    attributes: ["id", "index", "name"],
+  });
+
+  const sortable = naturalSort(collections, (collection) => collection.name);
+
+  // for each collection with null index, use previous collection index to create new index
+  let previousIndex = null;
+  const promises = [];
+
+  for (const collection of sortable) {
+    if (collection.index === null) {
+      collection.index = fractionalIndex(previousIndex, null);
+      promises.push(collection.save());
+    }
+
+    previousIndex = collection.index;
+  }
+
+  await Promise.all(promises);
+
+  const indexedCollections = {};
+  sortable.forEach((collection) => {
+    indexedCollections[collection.id] = collection.index;
+  });
+  return indexedCollections;
+}
+
+export async function starIndexing(
+  userId: string
+): Promise<{ [id: string]: string }> {
+  const stars = await Star.findAll({
+    where: { userId },
+  });
+
+  const documents = await Document.findAll({
+    attributes: ["id", "updatedAt"],
+    where: {
+      id: stars.map((star) => star.documentId),
+    },
+    order: [["updatedAt", "DESC"]],
+  });
+
+  const sortable = stars.sort(function (a, b) {
+    return (
+      documents.findIndex((d) => d.id === a.documentId) -
+      documents.findIndex((d) => d.id === b.documentId)
+    );
+  });
+
+  let previousIndex = null;
+  const promises = [];
+
+  for (const star of sortable) {
+    if (star.index === null) {
+      star.index = fractionalIndex(previousIndex, null);
+      promises.push(star.save());
+    }
+
+    previousIndex = star.index;
+  }
+
+  await Promise.all(promises);
+
+  const indexedStars = {};
+  sortable.forEach((star) => {
+    indexedStars[star.id] = star.index;
+  });
+  return indexedStars;
+}