Add dubz replacer

src/link_embed/dubz.rs

@@ -0,0 +1,26 @@
+use once_cell::sync::Lazy;
+use regex::Regex;
+use url::Url;
+
+use super::UrlReplacer;
+
+impl UrlReplacer {
+    pub async fn replace_dubz(url: &url::Url) -> Vec<Url> {
+        static PATH_RE: Lazy<Regex> = Lazy::new(|| Regex::new(r"^/c/(?P<id>\w+)").unwrap());
+        let url = PATH_RE
+            .captures(url.path())
+            .map(|cap| cap.name("id").unwrap())
+            .and_then(|id| {
+                Url::parse(&format!(
+                    "https://dubzalt.com/storage/videos/{}.mp4",
+                    id.as_str()
+                ))
+                .ok()
+            });
+        if let Some(url) = url {
+            vec![url]
+        } else {
+            Vec::new()
+        }
+    }
+}