From 6ef977be9cd409806cd73068b00642c8ec013334 Mon Sep 17 00:00:00 2001
From: Manav Rathi <manav@mnvr.in>
Date: Tue, 18 Mar 2025 19:14:16 +0530
Subject: [PATCH] Sketch

---
 web/packages/gallery/services/video.ts        | 35 +++++++++++++++++--
 web/packages/new/photos/services/file-data.ts | 24 +++++++++++--
 .../new/photos/services/ml/ml-data.ts         |  4 +--
 3 files changed, 56 insertions(+), 7 deletions(-)

diff --git a/web/packages/gallery/services/video.ts b/web/packages/gallery/services/video.ts
index 948e2acffa..a6f908050d 100644
--- a/web/packages/gallery/services/video.ts
+++ b/web/packages/gallery/services/video.ts
@@ -1,13 +1,42 @@
+import { assertionFailed } from "@/base/assert";
 import type { EnteFile } from "@/media/file";
-import { wait } from "@/utils/promise";
+import { FileType } from "@/media/file-type";
+import { fetchFileData } from "@/new/photos/services/file-data";
 
 /**
  * Return a HLS playlist that can be used to stream playback of thne given video
  * {@link file}.
  *
- * @param file An {@link EnteFile} of type
+ * @param file An {@link EnteFile} of type video.
+ *
+ * [Note: Video playlist vs preview]
+ *
+ * In museum's ontology, there is a distinction between two concepts:
+ *
+ * S3 metadata is the data that museum uploads (on behalf of the client):
+ * - ML data.
+ * - Preview video playlist.
+ *
+ * S3 file data is the data that client uploads:
+ * - Preview video itself.
+ * - Additional preview images.
+ *
+ * Because of this separation, there are separate code paths dealing with the
+ * two parts we need to play streaming video:
+ *
+ * - The encrypted HLS playlist (which is stored as file data of type
+ *   "vid_preview"),
+ *
+ * - And the encrypted video chunks that it (the playlist) refers to (which are
+ *   stored as file preview data of type "vid_preview").
  */
 export const hlsPlaylistForFile = async (file: EnteFile) => {
-    await wait(0);
+    if (file.metadata.fileType != FileType.video) {
+        assertionFailed();
+        return undefined;
+    }
+
+    const encryptedHLS = await fetchFileData("vid_preview", file.id);
+    console.log(encryptedHLS);
     return file.id;
 };
diff --git a/web/packages/new/photos/services/file-data.ts b/web/packages/new/photos/services/file-data.ts
index c7367ccbea..0940e7dd5d 100644
--- a/web/packages/new/photos/services/file-data.ts
+++ b/web/packages/new/photos/services/file-data.ts
@@ -18,7 +18,9 @@ import { z } from "zod";
  * There are specialized APIs for fetching and uploading the originals and the
  * thumbnails. But for the other associated data, we can use the file data APIs.
  */
-type FileDataType = "mldata" /* See: [Note: "mldata" format] */;
+type FileDataType =
+    | "mldata" /* See: [Note: "mldata" format] */
+    | "vid_preview" /* See: [Note: Video playlist vs preview] */;
 
 const RemoteFileData = z.object({
     /**
@@ -61,7 +63,7 @@ type RemoteFileData = z.infer<typeof RemoteFileData>;
  * payload, but we don't parse that information currently since the higher
  * levels of our code that use this function handle such rare skips gracefully.
  */
-export const fetchFileData = async (
+export const fetchFilesData = async (
     type: FileDataType,
     fileIDs: number[],
 ): Promise<RemoteFileData[]> => {
@@ -75,6 +77,24 @@ export const fetchFileData = async (
         .data;
 };
 
+/**
+ * A variant of {@link fetchFilesData} that fetches data for a single file.
+ *
+ * Unlike {@link fetchFilesData}, this uses a HTTP GET request.
+ */
+export const fetchFileData = async (
+    type: FileDataType,
+    fileID: number,
+): Promise<RemoteFileData> => {
+    const params = new URLSearchParams({ type, fileID: fileID.toString() });
+    const url = await apiURL("/files/data/fetch");
+    const res = await fetch(`${url}?${params.toString()}`, {
+        headers: await authenticatedRequestHeaders(),
+    });
+    ensureOk(res);
+    return z.object({ data: RemoteFileData }).parse(await res.json()).data;
+};
+
 /**
  * Upload file data associated with the given file to remote.
  *
diff --git a/web/packages/new/photos/services/ml/ml-data.ts b/web/packages/new/photos/services/ml/ml-data.ts
index fc6313a25f..58a3d52dd0 100644
--- a/web/packages/new/photos/services/ml/ml-data.ts
+++ b/web/packages/new/photos/services/ml/ml-data.ts
@@ -4,7 +4,7 @@ import type { EnteFile } from "@/media/file";
 import { nullToUndefined } from "@/utils/transform";
 import { z } from "zod";
 import { gunzip, gzip } from "../../utils/gzip";
-import { fetchFileData, putFileData } from "../file-data";
+import { fetchFilesData, putFileData } from "../file-data";
 import { type RemoteCLIPIndex } from "./clip";
 import { type RemoteFaceIndex } from "./face";
 
@@ -153,7 +153,7 @@ const ParsedRemoteMLData = z.object({
 export const fetchMLData = async (
     filesByID: Map<number, EnteFile>,
 ): Promise<Map<number, RemoteMLData>> => {
-    const remoteFileDatas = await fetchFileData("mldata", [
+    const remoteFileDatas = await fetchFilesData("mldata", [
         ...filesByID.keys(),
     ]);