PIT: Add folder reconstruction functions

backend/src/services/folder-checkpoint/folder-checkpoint-dal.ts

@@ -1,7 +1,7 @@
 import { Knex } from "knex";
 
 import { TDbClient } from "@app/db";
-import { TableName, TFolderCheckpoints } from "@app/db/schemas";
+import { TableName, TFolderCheckpoints, TFolderCommits } from "@app/db/schemas";
 import { DatabaseError } from "@app/lib/errors";
 import { buildFindFilter, ormify, selectAllTableCols } from "@app/lib/knex";
 
@@ -33,7 +33,11 @@ export const folderCheckpointDALFactory = (db: TDbClient) => {
   const findByFolderId = async (folderId: string, limit?: number, tx?: Knex): Promise<CheckpointWithCommitInfo[]> => {
     try {
       let query = (tx || db.replicaNode())(TableName.FolderCheckpoint)
-        .join(TableName.FolderCommit, `${TableName.FolderCheckpoint}.folderCommitId`, `${TableName.FolderCommit}.id`)
+        .join<TFolderCommits>(
+          TableName.FolderCommit,
+          `${TableName.FolderCheckpoint}.folderCommitId`,
+          `${TableName.FolderCommit}.id`
+        )
         // eslint-disable-next-line @typescript-eslint/no-misused-promises
         .where(buildFindFilter({ folderId }, TableName.FolderCommit))
         .select(selectAllTableCols(TableName.FolderCheckpoint))
@@ -50,8 +54,7 @@ export const folderCheckpointDALFactory = (db: TDbClient) => {
         query = query.limit(limit);
       }
 
-      const docs = await query;
-      return docs;
+      return await query;
     } catch (error) {
       throw new DatabaseError({ error, name: "FindByFolderId" });
     }
@@ -60,7 +63,11 @@ export const folderCheckpointDALFactory = (db: TDbClient) => {
   const findLatestByFolderId = async (folderId: string, tx?: Knex): Promise<CheckpointWithCommitInfo | undefined> => {
     try {
       const doc = await (tx || db.replicaNode())(TableName.FolderCheckpoint)
-        .join(TableName.FolderCommit, `${TableName.FolderCheckpoint}.folderCommitId`, `${TableName.FolderCommit}.id`)
+        .join<TFolderCommits>(
+          TableName.FolderCommit,
+          `${TableName.FolderCheckpoint}.folderCommitId`,
+          `${TableName.FolderCommit}.id`
+        )
         // eslint-disable-next-line @typescript-eslint/no-misused-promises
         .where(buildFindFilter({ folderId }, TableName.FolderCommit))
         .select(selectAllTableCols(TableName.FolderCheckpoint))
@@ -79,10 +86,53 @@ export const folderCheckpointDALFactory = (db: TDbClient) => {
     }
   };
 
+  const findNearestCheckpoint = async (
+    folderCommitId: string,
+    tx?: Knex
+  ): Promise<(CheckpointWithCommitInfo & { commitId: number }) | undefined> => {
+    try {
+      // First, get the commit info to find the folder ID and commit sequence number
+      const commit = await (tx || db.replicaNode())(TableName.FolderCommit)
+        .where({ id: folderCommitId })
+        .select("commitId", "folderId")
+        .first();
+
+      if (!commit) {
+        return undefined;
+      }
+
+      // Get the checkpoint with the highest commitId that's still less than or equal to our commit
+      const nearestCheckpoint = await (tx || db.replicaNode())(TableName.FolderCheckpoint)
+        .join<TFolderCommits>(
+          TableName.FolderCommit,
+          `${TableName.FolderCheckpoint}.folderCommitId`,
+          `${TableName.FolderCommit}.id`
+        )
+        .where(`${TableName.FolderCommit}.folderId`, commit.folderId)
+        .where(`${TableName.FolderCommit}.commitId`, "<=", commit.commitId.toString())
+        .select(selectAllTableCols(TableName.FolderCheckpoint))
+        .select(
+          db.ref("actorMetadata").withSchema(TableName.FolderCommit),
+          db.ref("actorType").withSchema(TableName.FolderCommit),
+          db.ref("message").withSchema(TableName.FolderCommit),
+          db.ref("commitId").withSchema(TableName.FolderCommit),
+          db.ref("createdAt").withSchema(TableName.FolderCommit).as("commitDate"),
+          db.ref("folderId").withSchema(TableName.FolderCommit)
+        )
+        .orderBy(`${TableName.FolderCommit}.commitId`, "desc")
+        .first();
+
+      return nearestCheckpoint;
+    } catch (error) {
+      throw new DatabaseError({ error, name: "FindNearestCheckpoint" });
+    }
+  };
+
   return {
     ...folderCheckpointOrm,
     findByCommitId,
     findByFolderId,
-    findLatestByFolderId
+    findLatestByFolderId,
+    findNearestCheckpoint
   };
 };