Use a MIME DB to determine the download URL file extensions

* Also apply it to the default MIME type for Mixcloud posts
* Add a dependency on the `mime_db` crate

Cargo.lock

@@ -1218,6 +1218,17 @@ version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2a60c7ce501c71e03a9c9c0d35b861413ae925bd979cc7a4e30d060069aaac8d"
 
+[[package]]
+name = "mime-db"
+version = "1.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6d7c816ec30c41f873e1eea969aa2261d78756629e468a427244ff8658b75e7d"
+dependencies = [
+ "reqwest",
+ "serde",
+ "tokio",
+]
+
 [[package]]
 name = "mio"
 version = "0.6.23"
@@ -1627,6 +1638,7 @@ dependencies = [
  "cached",
  "chrono",
  "enum_dispatch",
+ "mime-db",
  "reqwest",
  "rocket",
  "rocket_dyn_templates",

Cargo.toml

@@ -12,6 +12,7 @@ async-trait = "0.1.57"
 cached = { version = "0.39.0", features = ["async"] }
 chrono = { version = "0.4.19", features = ["serde"] }
 enum_dispatch = "0.3.8"
+mime-db = "1.6.0"
 reqwest = { version = "0.11.10", features = ["json"] }
 rocket = { version = "0.5.0-rc.2", features = ["json"] }
 rocket_dyn_templates = { version = "0.1.0-rc.2", features = ["tera"] }

src/backends/mixcloud.rs

@@ -199,7 +199,8 @@ impl From<UserWithCloudcasts> for Channel {
 impl From<Cloudcast> for Item {
     fn from(cloudcast: Cloudcast) -> Self {
         let mut file = PathBuf::from(cloudcast.key.trim_end_matches('/'));
-        file.set_extension("m4a"); // FIXME: Don't hardcoded the extension!
+        let extension = mime_db::extension(DEFAULT_FILE_TYPE).expect("MIME type has extension");
+        file.set_extension(extension);
 
         // FIXME: Don't hardcode the description!
         let description = Some(format!("Taken from Mixcloud: {0}", cloudcast.url));

src/backends/youtube.rs

@@ -168,19 +168,25 @@ impl From<YouTubeVideoWithStream> for Item {
         YouTubeVideoWithStream {
             video,
             stream,
-            content_length,
+            content_length: length,
         }: YouTubeVideoWithStream,
     ) -> Self {
         let id = video.id().to_string();
-        let mut link = Url::parse(VIDEO_BASE_URL).expect("valid URL");
-        let description = Some(format!("Taken from YouTube: {0}", link));
-        link.query_pairs_mut().append_pair("v", &id);
+
+        let mime_type = stream.mime_type().to_string();
+        // Ignore everything from MIME type parameter seperator on for extension look-up.
+        let mime_sep = mime_type.find(';').unwrap_or(mime_type.len());
+        let extension = mime_db::extension(&mime_type[..mime_sep]).unwrap_or_default();
+        let file = PathBuf::from(&id).with_extension(extension);
         let enclosure = Enclosure {
-            file: PathBuf::from(&format!("{id}.webm")), // FIXME: Don't hardcode the extension!
-            mime_type: stream.mime_type().to_string(),
-            length: content_length,
+            file,
+            mime_type,
+            length,
         };
 
+        let mut link = Url::parse(VIDEO_BASE_URL).expect("valid URL");
+        link.query_pairs_mut().append_pair("v", &id);
+        let description = Some(format!("Taken from YouTube: {0}", link));
         let duration = Some(video.length().as_secs() as u32);
         let image = video
             .thumbnails()