fix(overlay): restore mpv focus and pointer state on macOS (#104)

src/main/runtime/macos-mpv-focus.ts

@@ -0,0 +1,35 @@
+import { execFile as nodeExecFile } from 'node:child_process';
+
+const FOCUS_MPV_PROCESS_SCRIPT =
+  'tell application "System Events" to set frontmost of the first process whose name is "mpv" to true';
+
+type ExecFileForMacOSFocus = (
+  command: string,
+  args: string[],
+  options: { timeout: number },
+  callback: (error: Error | null) => void,
+) => void;
+
+export type MacOSMpvFocusDeps = {
+  execFile?: ExecFileForMacOSFocus;
+};
+
+export async function focusMacOSMpvProcess(deps: MacOSMpvFocusDeps = {}): Promise<void> {
+  const execFile: ExecFileForMacOSFocus =
+    deps.execFile ??
+    ((command, args, options, callback) => {
+      nodeExecFile(command, args, options, (error) => {
+        callback(error);
+      });
+    });
+
+  await new Promise<void>((resolve, reject) => {
+    execFile('/usr/bin/osascript', ['-e', FOCUS_MPV_PROCESS_SCRIPT], { timeout: 2000 }, (error) => {
+      if (error) {
+        reject(error);
+        return;
+      }
+      resolve();
+    });
+  });
+}