more changes

src/transcription_downloader.rs

@@ -1,17 +1,14 @@
-// Manages the download of asset files for transcription courses.
-//
-// Transcription courses include references to the assets used in the course. Manually downloading
-// them is a cumbersome process, so this module automates the process.
+//! Manages the download of asset files for transcription courses.
+//!
+//! Transcription courses include references to external assets. Manually downloading them is a
+//! cumbersome process, so this module automates the process.
 
 use crate::{
     data::course_generator::transcription::TranscriptionAsset, TranscriptionDownloaderError,
 };
 
 /// Downloads transcription assets to local storage.
 pub trait TranscriptionDownloader {
-    /// Performs any initialization required to download assets.
-    fn initialize(&self) -> Result<(), TranscriptionDownloaderError>;
-
     /// Downloads the given asset.
     fn download_asset(&self, asset: TranscriptionAsset)
         -> Result<(), TranscriptionDownloaderError>;
@@ -21,4 +18,18 @@ pub trait TranscriptionDownloader {
         &self,
         asset: &TranscriptionAsset,
     ) -> Result<bool, TranscriptionDownloaderError>;
+
+    /// Downloads all assets for all the transcription courses in the current Trane library.
+    fn download_all_assets(&self) -> Result<(), TranscriptionDownloaderError>;
+}
+
+/// An implementation of `TranscriptionDownloader` that downloads assets to a directory inside the
+/// `.trane` directory.
+pub struct LocalTranscriptionDownloader {}
+
+impl LocalTranscriptionDownloader {
+    /// Creates a new `LocalTranscriptionDownloader`.
+    pub fn new() -> Self {
+        Self{}
+    }
 }