feat: a2ui interface to enablee the LLM to give structured information

src/native_media.rs

@@ -0,0 +1,39 @@
+use std::ffi::{CString, c_char};
+
+unsafe extern "C" {
+    fn ds4_media_open(url: *const c_char, title: *const c_char, video: bool) -> bool;
+}
+
+pub(crate) fn open(url: &str, title: &str, video: bool) -> Result<(), String> {
+    let url = playable_url(url)?;
+    let url = CString::new(url.as_str()).map_err(|error| error.to_string())?;
+    let title = CString::new(title).map_err(|error| error.to_string())?;
+    // SAFETY: Both C strings live for the duration of the call; Objective-C copies them.
+    if unsafe { ds4_media_open(url.as_ptr(), title.as_ptr(), video) } {
+        Ok(())
+    } else {
+        Err("AVKit could not create the media player".into())
+    }
+}
+
+fn playable_url(value: &str) -> Result<url::Url, String> {
+    let url = url::Url::parse(value).map_err(|error| format!("invalid media URL: {error}"))?;
+    if matches!(url.scheme(), "http" | "https") {
+        Ok(url)
+    } else {
+        Err("media URLs must use HTTP(S)".into())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn media_player_only_accepts_remote_http_urls() {
+        assert!(playable_url("https://example.com/video.mp4").is_ok());
+        assert!(playable_url("http://example.com/audio.mp3").is_ok());
+        assert!(playable_url("file:///tmp/private.mov").is_err());
+        assert!(playable_url("javascript:alert(1)").is_err());
+    }
+}