♻️ refactor: extract routing func

crates/ptth_server/src/file_server/internal.rs

@@ -250,6 +250,31 @@ pub struct FileRoots <'a> {
 	pub dirs: &'a BTreeMap <String, PathBuf>,
 }
 
+struct RoutedPath <'a> {
+	root: &'a Path,
+	path: std::borrow::Cow <'a, str>,
+}
+
+impl <'a> FileRoots <'a> {
+	fn route (self, input: &'a str) -> Result <Option <RoutedPath>, FileServerError> {
+		let path = match input.strip_prefix ("/files/") {
+			Some (x) => x,
+			None => return Ok (None),
+		};
+		
+		// TODO: There is totally a dir traversal attack in here somewhere
+		
+		let encoded_path = &path [0..];
+		
+		let path = percent_decode (encoded_path.as_bytes ()).decode_utf8 ().map_err (FileServerError::PathNotUtf8)?;
+		
+		Ok (Some (RoutedPath {
+			root: self.files,
+			path,
+		}))
+	}
+}
+
 // Handle the requests internally without knowing anything about PTTH or
 // HTML / handlebars