/api/file/[id]/thumbnail, /api/file/[id]/thumbnail/download, /api/file/[id]/thumbnail/upload Endpoint 구현

src/lib/server/db/file.ts

@@ -327,7 +327,8 @@ export const getAllFilesByCategory = async (
     .where("user_id", "=", userId)
     .where("file_id", "is not", null)
     .$narrowType<{ file_id: NotNull }>()
-    .orderBy(["file_id", "depth"])
+    .orderBy("file_id")
+    .orderBy("depth")
     .execute();
   return files.map(({ file_id, depth }) => ({ id: file_id, isRecursive: depth > 0 }));
 };

src/lib/server/db/media.ts

@@ -0,0 +1,86 @@
+import type { NotNull } from "kysely";
+import { IntegrityError } from "./error";
+import db from "./kysely";
+
+interface Thumbnail {
+  id: number;
+  path: string;
+  createdAt: Date;
+  encContentIv: string;
+}
+
+interface FileThumbnail extends Thumbnail {
+  fileId: number;
+}
+
+export const updateFileThumbnail = async (
+  userId: number,
+  fileId: number,
+  dekVersion: Date,
+  path: string,
+  encContentIv: string,
+) => {
+  return await db.transaction().execute(async (trx) => {
+    const file = await trx
+      .selectFrom("file")
+      .select("data_encryption_key_version")
+      .where("id", "=", fileId)
+      .where("user_id", "=", userId)
+      .limit(1)
+      .forUpdate()
+      .executeTakeFirst();
+    if (!file) {
+      throw new IntegrityError("File not found");
+    } else if (file.data_encryption_key_version.getTime() !== dekVersion.getTime()) {
+      throw new IntegrityError("Invalid DEK version");
+    }
+
+    const thumbnail = await trx
+      .selectFrom("thumbnail")
+      .select("path as old_path")
+      .where("file_id", "=", fileId)
+      .limit(1)
+      .forUpdate()
+      .executeTakeFirst();
+    const now = new Date();
+
+    await trx
+      .insertInto("thumbnail")
+      .values({
+        file_id: fileId,
+        path,
+        created_at: now,
+        encrypted_content_iv: encContentIv,
+      })
+      .onConflict((oc) =>
+        oc.column("file_id").doUpdateSet({
+          path,
+          created_at: now,
+          encrypted_content_iv: encContentIv,
+        }),
+      )
+      .execute();
+    return thumbnail?.old_path;
+  });
+};
+
+export const getFileThumbnail = async (userId: number, fileId: number) => {
+  const thumbnail = await db
+    .selectFrom("thumbnail")
+    .innerJoin("file", "thumbnail.file_id", "file.id")
+    .selectAll("thumbnail")
+    .where("file.id", "=", fileId)
+    .where("file.user_id", "=", userId)
+    .$narrowType<{ file_id: NotNull }>()
+    .limit(1)
+    .executeTakeFirst();
+  return thumbnail
+    ? ({
+        id: thumbnail.id,
+        fileId: thumbnail.file_id,
+        path: thumbnail.path,
+        encContentIv: thumbnail.encrypted_content_iv,
+        createdAt: thumbnail.created_at,
+      } satisfies FileThumbnail)
+    : null;
+};

src/lib/server/db/schema/media.ts

@@ -1,4 +1,4 @@
-import type { ColumnType, Generated } from "kysely";
+import type { Generated } from "kysely";
 
 interface ThumbnailTable {
   id: Generated<number>;
@@ -6,7 +6,7 @@ interface ThumbnailTable {
   file_id: number | null;
   category_id: number | null;
   path: string;
-  created_at: ColumnType<Date, Date, never>;
+  created_at: Date;
   encrypted_content_iv: string; // Base64
 }
 

src/lib/server/loadenv.ts

@@ -25,4 +25,5 @@ export default {
     sessionUpgradeExp: ms(env.SESSION_UPGRADE_CHALLENGE_EXPIRES || "5m"),
   },
   libraryPath: env.LIBRARY_PATH || "library",
+  thumbnailsPath: env.THUMBNAILS_PATH || "thumbnails",
 };

src/lib/server/schemas/file.ts

@@ -30,6 +30,17 @@ export const fileRenameRequest = z.object({
 });
 export type FileRenameRequest = z.infer<typeof fileRenameRequest>;
 
+export const fileThumbnailInfoResponse = z.object({
+  encContentIv: z.string().base64().nonempty(),
+});
+export type FileThumbnailInfoResponse = z.infer<typeof fileThumbnailInfoResponse>;
+
+export const fileThumbnailUploadRequest = z.object({
+  dekVersion: z.string().datetime(),
+  encContentIv: z.string().base64().nonempty(),
+});
+export type FileThumbnailUploadRequest = z.infer<typeof fileThumbnailUploadRequest>;
+
 export const duplicateFileScanRequest = z.object({
   hskVersion: z.number().int().positive(),
   contentHmac: z.string().base64().nonempty(),

src/lib/server/services/file.ts

@@ -16,6 +16,7 @@ import {
   getAllFileCategories,
   type NewFile,
 } from "$lib/server/db/file";
+import { getFileThumbnail, updateFileThumbnail } from "$lib/server/db/media";
 import type { Ciphertext } from "$lib/server/db/schema";
 import env from "$lib/server/loadenv";
 
@@ -85,6 +86,59 @@ export const renameFile = async (
   }
 };
 
+export const getFileThumbnailInformation = async (userId: number, fileId: number) => {
+  const thumbnail = await getFileThumbnail(userId, fileId);
+  if (!thumbnail) {
+    error(404, "File or its thumbnail not found");
+  }
+
+  return { encContentIv: thumbnail.encContentIv };
+};
+
+export const getFileThumbnailStream = async (userId: number, fileId: number) => {
+  const thumbnail = await getFileThumbnail(userId, fileId);
+  if (!thumbnail) {
+    error(404, "File or its thumbnail not found");
+  }
+
+  const { size } = await stat(thumbnail.path);
+  return {
+    encContentStream: Readable.toWeb(createReadStream(thumbnail.path)),
+    encContentSize: size,
+  };
+};
+
+export const uploadFileThumbnail = async (
+  userId: number,
+  fileId: number,
+  dekVersion: Date,
+  encContentIv: string,
+  encContentStream: Readable,
+) => {
+  const path = `${env.thumbnailsPath}/${userId}/${uuidv4()}`;
+  await mkdir(dirname(path), { recursive: true });
+
+  try {
+    await pipeline(encContentStream, createWriteStream(path, { flags: "wx", mode: 0o600 }));
+
+    const oldPath = await updateFileThumbnail(userId, fileId, dekVersion, path, encContentIv);
+    if (oldPath) {
+      safeUnlink(oldPath); // Intended
+    }
+  } catch (e) {
+    await safeUnlink(path);
+
+    if (e instanceof IntegrityError) {
+      if (e.message === "File not found") {
+        error(404, "File not found");
+      } else if (e.message === "Invalid DEK version") {
+        error(400, "Mismatched DEK version");
+      }
+    }
+    throw e;
+  }
+};
+
 export const scanDuplicateFiles = async (
   userId: number,
   hskVersion: number,