From 1e5e98482ab93ff54c536217e450751fb6297b69 Mon Sep 17 00:00:00 2001
From: sudacode <suda@sudacode.com>
Date: Sun, 29 Mar 2026 15:59:12 -0700
Subject: [PATCH] fix: lazily resolve youtube playback socket path

---
 changes/252-youtube-playback-socket-path.md   |  5 ++
 src/main.ts                                   |  2 +-
 .../runtime/youtube-playback-runtime.test.ts  | 70 ++++++++++++++++++-
 src/main/runtime/youtube-playback-runtime.ts  |  5 +-
 4 files changed, 78 insertions(+), 4 deletions(-)
 create mode 100644 changes/252-youtube-playback-socket-path.md

diff --git a/changes/252-youtube-playback-socket-path.md b/changes/252-youtube-playback-socket-path.md
new file mode 100644
index 0000000..71e099b
--- /dev/null
+++ b/changes/252-youtube-playback-socket-path.md
@@ -0,0 +1,5 @@
+type: fixed
+area: main
+
+- Resolve the YouTube playback socket path lazily so startup honors CLI and config overrides.
+- Add regression coverage for the lazy socket-path lookup during Windows mpv startup.
diff --git a/src/main.ts b/src/main.ts
index 9a65f43..4fc5f03 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -1003,7 +1003,7 @@ const youtubePlaybackRuntime = createYoutubePlaybackRuntime({
   mpvYtdlFormat: YOUTUBE_MPV_YTDL_FORMAT,
   autoLaunchTimeoutMs: YOUTUBE_MPV_AUTO_LAUNCH_TIMEOUT_MS,
   connectTimeoutMs: YOUTUBE_MPV_CONNECT_TIMEOUT_MS,
-  socketPath: appState.mpvSocketPath,
+  getSocketPath: () => appState.mpvSocketPath,
   getMpvConnected: () => Boolean(appState.mpvClient?.connected),
   invalidatePendingAutoplayReadyFallbacks: () =>
     autoplayReadyGate.invalidatePendingAutoplayReadyFallbacks(),
diff --git a/src/main/runtime/youtube-playback-runtime.test.ts b/src/main/runtime/youtube-playback-runtime.test.ts
index e97d3db..5208bfc 100644
--- a/src/main/runtime/youtube-playback-runtime.test.ts
+++ b/src/main/runtime/youtube-playback-runtime.test.ts
@@ -6,6 +6,7 @@ test('youtube playback runtime resets flow ownership after a successful run', as
   const calls: string[] = [];
   let appOwnedFlowInFlight = false;
   let timeoutCallback: (() => void) | null = null;
+  let socketPath = '/tmp/mpv.sock';
 
   const runtime = createYoutubePlaybackRuntime({
     platform: 'linux',
@@ -13,7 +14,7 @@ test('youtube playback runtime resets flow ownership after a successful run', as
     mpvYtdlFormat: 'bestvideo+bestaudio',
     autoLaunchTimeoutMs: 2_000,
     connectTimeoutMs: 1_000,
-    socketPath: '/tmp/mpv.sock',
+    getSocketPath: () => socketPath,
     getMpvConnected: () => true,
     invalidatePendingAutoplayReadyFallbacks: () => {
       calls.push('invalidate-autoplay');
@@ -78,3 +79,70 @@ test('youtube playback runtime resets flow ownership after a successful run', as
   scheduledCallback();
   assert.equal(runtime.getQuitOnDisconnectArmed(), true);
 });
+
+test('youtube playback runtime resolves the socket path lazily for windows startup', async () => {
+  const calls: string[] = [];
+  let socketPath = '/tmp/initial.sock';
+
+  const runtime = createYoutubePlaybackRuntime({
+    platform: 'win32',
+    directPlaybackFormat: 'best',
+    mpvYtdlFormat: 'bestvideo+bestaudio',
+    autoLaunchTimeoutMs: 2_000,
+    connectTimeoutMs: 1_000,
+    getSocketPath: () => socketPath,
+    getMpvConnected: () => false,
+    invalidatePendingAutoplayReadyFallbacks: () => {
+      calls.push('invalidate-autoplay');
+    },
+    setAppOwnedFlowInFlight: (next) => {
+      calls.push(`app-owned:${next}`);
+    },
+    ensureYoutubePlaybackRuntimeReady: async () => {
+      calls.push('ensure-runtime-ready');
+    },
+    resolveYoutubePlaybackUrl: async (url, format) => {
+      calls.push(`resolve:${url}:${format}`);
+      return 'https://example.com/direct';
+    },
+    launchWindowsMpv: (_playbackUrl, args) => {
+      calls.push(`launch:${args.join(' ')}`);
+      return { ok: true, mpvPath: '/usr/bin/mpv' };
+    },
+    waitForYoutubeMpvConnected: async (timeoutMs) => {
+      calls.push(`wait-connected:${timeoutMs}`);
+      return true;
+    },
+    prepareYoutubePlaybackInMpv: async ({ url }) => {
+      calls.push(`prepare:${url}`);
+      return true;
+    },
+    runYoutubePlaybackFlow: async ({ url, mode }) => {
+      calls.push(`run-flow:${url}:${mode}`);
+    },
+    logInfo: (message) => {
+      calls.push(`info:${message}`);
+    },
+    logWarn: (message) => {
+      calls.push(`warn:${message}`);
+    },
+    schedule: (callback) => {
+      calls.push('schedule-arm');
+      callback();
+      return 1 as never;
+    },
+    clearScheduled: () => {
+      calls.push('clear-scheduled');
+    },
+  });
+
+  socketPath = '/tmp/updated.sock';
+
+  await runtime.runYoutubePlaybackFlow({
+    url: 'https://youtu.be/demo',
+    mode: 'download',
+    source: 'initial',
+  });
+
+  assert.ok(calls.some((entry) => entry.includes('--input-ipc-server=/tmp/updated.sock')));
+});
diff --git a/src/main/runtime/youtube-playback-runtime.ts b/src/main/runtime/youtube-playback-runtime.ts
index 8999728..0bf0815 100644
--- a/src/main/runtime/youtube-playback-runtime.ts
+++ b/src/main/runtime/youtube-playback-runtime.ts
@@ -11,7 +11,7 @@ export type YoutubePlaybackRuntimeDeps = {
   mpvYtdlFormat: string;
   autoLaunchTimeoutMs: number;
   connectTimeoutMs: number;
-  socketPath: string;
+  getSocketPath: () => string;
   getMpvConnected: () => boolean;
   invalidatePendingAutoplayReadyFallbacks: () => void;
   setAppOwnedFlowInFlight: (next: boolean) => void;
@@ -76,6 +76,7 @@ export function createYoutubePlaybackRuntime(deps: YoutubePlaybackRuntimeDeps) {
       }
 
       if (deps.platform === 'win32' && !deps.getMpvConnected()) {
+        const socketPath = deps.getSocketPath();
         const launchResult = deps.launchWindowsMpv(playbackUrl, [
           '--pause=yes',
           '--ytdl=yes',
@@ -87,7 +88,7 @@ export function createYoutubePlaybackRuntime(deps: YoutubePlaybackRuntimeDeps) {
           '--secondary-sub-visibility=no',
           '--alang=ja,jp,jpn,japanese,en,eng,english,enus,en-us',
           '--slang=ja,jp,jpn,japanese,en,eng,english,enus,en-us',
-          `--input-ipc-server=${deps.socketPath}`,
+          `--input-ipc-server=${socketPath}`,
         ]);
         launchedWindowsMpv = launchResult.ok;
         if (launchResult.ok && launchResult.mpvPath) {