From df7144ede9617a9ba6bf7095913f6353f92cb9bc Mon Sep 17 00:00:00 2001
From: Fredrik Burmester <fredrik.burmester@gmail.com>
Date: Sat, 15 Feb 2025 23:26:28 +0100
Subject: [PATCH] wip

---
 bun.lock                             |   1 +
 package.json                         |   1 +
 providers/NativeDownloadProvider.tsx |   3 +
 utils/hls/av-file-parser.ts          | 104 +++++++++++++++++++++++++++
 4 files changed, 109 insertions(+)
 create mode 100644 utils/hls/av-file-parser.ts

diff --git a/bun.lock b/bun.lock
index ed72b3a9..448a563e 100644
--- a/bun.lock
+++ b/bun.lock
@@ -54,6 +54,7 @@
         "expo-task-manager": "~12.0.5",
         "expo-updates": "~0.26.17",
         "expo-web-browser": "~14.0.2",
+        "fast-xml-parser": "^4.5.1",
         "ffmpeg-kit-react-native": "^6.0.2",
         "i18next": "^24.2.2",
         "jotai": "^2.11.3",
diff --git a/package.json b/package.json
index 8618924c..bedc47dd 100644
--- a/package.json
+++ b/package.json
@@ -68,6 +68,7 @@
     "expo-task-manager": "~12.0.5",
     "expo-updates": "~0.26.17",
     "expo-web-browser": "~14.0.2",
+    "fast-xml-parser": "^4.5.1",
     "ffmpeg-kit-react-native": "^6.0.2",
     "i18next": "^24.2.2",
     "jotai": "^2.11.3",
diff --git a/providers/NativeDownloadProvider.tsx b/providers/NativeDownloadProvider.tsx
index 179545a9..b2c05f58 100644
--- a/providers/NativeDownloadProvider.tsx
+++ b/providers/NativeDownloadProvider.tsx
@@ -12,6 +12,7 @@ import {
 } from "@/modules/hls-downloader";
 import * as FileSystem from "expo-file-system";
 import { DownloadInfo } from "@/modules/hls-downloader/src/HlsDownloader.types";
+import { processStream } from "@/utils/hls/av-file-parser";
 
 type DownloadContextType = {
   downloads: Record<string, DownloadInfo>;
@@ -124,6 +125,8 @@ export const NativeDownloadProvider: React.FC<{
               payload.metadata.Name
             );
             console.log("File successfully persisted to:", newLocation);
+
+            processStream(newLocation);
           } else {
             console.log(
               "No filename in metadata, using original location",
diff --git a/utils/hls/av-file-parser.ts b/utils/hls/av-file-parser.ts
new file mode 100644
index 00000000..02d56761
--- /dev/null
+++ b/utils/hls/av-file-parser.ts
@@ -0,0 +1,104 @@
+import * as FileSystem from "expo-file-system";
+import { XMLParser } from "fast-xml-parser";
+
+const parser = new XMLParser({
+  ignoreAttributes: false,
+  attributeNamePrefix: "@_",
+});
+
+export interface StreamDefinition {
+  id: string;
+  networkURL: string;
+  path: string;
+  complete: boolean;
+}
+
+export interface StreamInfo {
+  mediaPlaylistURL: string;
+  localM3U8: string;
+  segPaths: string[];
+}
+
+// 1. Parse boot.xml to extract stream definitions.
+export function parseBootXML(xml: string): StreamDefinition[] {
+  const json = parser.parse(xml);
+  const pkg = json.HLSMoviePackage;
+  const streams = pkg.Streams.Stream;
+  const streamArray: any[] = Array.isArray(streams) ? streams : [streams];
+  return streamArray.map((s) => ({
+    id: s["@_ID"],
+    networkURL: s["@_NetworkURL"],
+    path: s["@_Path"],
+    complete: s.Complete.trim() === "YES",
+  }));
+}
+
+// 2. Parse StreamInfoBoot.xml to extract the local m3u8 path and segment paths.
+export function parseStreamInfo(xml: string): StreamInfo {
+  const json = parser.parse(xml);
+  const streamInfo = json.StreamInfo;
+  const mediaPlaylist = streamInfo.MediaPlaylist;
+  const networkURL = mediaPlaylist.NetworkURL;
+  const pathToLocalCopy = mediaPlaylist.PathToLocalCopy;
+  let segs = mediaPlaylist?.MediaSegments?.SEG || [];
+  if (!Array.isArray(segs)) segs = [segs];
+  const segPaths = segs
+    .map((seg: any) => seg["@_PATH"])
+    .filter((p: string) => !!p);
+  return {
+    mediaPlaylistURL:
+      (typeof networkURL === "string" ? networkURL : networkURL?.trim()) || "",
+    localM3U8:
+      (typeof pathToLocalCopy === "string"
+        ? pathToLocalCopy
+        : pathToLocalCopy?.trim()) || "",
+    segPaths,
+  };
+}
+
+// 3. Update the m3u8 playlist content by replacing remote segment URLs with local paths.
+export function updatePlaylistWithLocalSegments(
+  playlistContent: string,
+  segPaths: string[]
+): string {
+  const lines = playlistContent.split("\n");
+  let segIndex = 0;
+  for (let i = 0; i < lines.length; i++) {
+    // Replace non-comment lines (assumed to be segment URIs) with local paths.
+    if (
+      lines[i].trim() &&
+      !lines[i].startsWith("#") &&
+      segIndex < segPaths.length
+    ) {
+      lines[i] = segPaths[segIndex++];
+    }
+  }
+  return lines.join("\n");
+}
+
+// Example: Process a stream directory using Expo FileSystem.
+export async function processStream(streamDir: string): Promise<void> {
+  // Read StreamInfoBoot.xml from the stream directory.
+  const streamInfoPath = `${streamDir}/StreamInfoBoot.xml`;
+  const streamInfoXML = await FileSystem.readAsStringAsync(streamInfoPath, {
+    encoding: FileSystem.EncodingType.UTF8,
+  });
+  const streamInfo = parseStreamInfo(streamInfoXML);
+
+  // Read the local m3u8 file.
+  const playlistPath = `${streamDir}/${streamInfo.localM3U8}`;
+  const playlistContent = await FileSystem.readAsStringAsync(playlistPath, {
+    encoding: FileSystem.EncodingType.UTF8,
+  });
+
+  // Replace remote segment URIs with local segment paths.
+  const updatedPlaylist = updatePlaylistWithLocalSegments(
+    playlistContent,
+    streamInfo.segPaths
+  );
+
+  // Save the updated playlist back to disk.
+  await FileSystem.writeAsStringAsync(playlistPath, updatedPlaylist, {
+    encoding: FileSystem.EncodingType.UTF8,
+  });
+}