Added some comments into the downloader module.

hammond-downloader/src/downloader.rs

@@ -14,19 +14,27 @@ use hammond_data::index_feed::Database;
 use hammond_data::models::{Episode, Podcast};
 use hammond_data::{DL_DIR, HAMMOND_CACHE};
 
+// TODO: Replace path that are of type &str with std::path.
+// TODO: Have a convention/document absolute/relative paths, if they should end with / or not.
+
 // Adapted from https://github.com/mattgathu/rget .
 // I never wanted to write a custom downloader.
 // Sorry to those who will have to work with that code.
 // Would much rather use a crate,
 // or bindings for a lib like youtube-dl(python),
 // But cant seem to find one.
+// TODO: Write unit-tests.
 fn download_into(dir: &str, file_title: &str, url: &str) -> Result<String> {
     info!("GET request to: {}", url);
     let client = reqwest::Client::builder().referer(false).build()?;
     let mut resp = client.get(url).send()?;
     info!("Status Resp: {}", resp.status());
 
-    if resp.status().is_success() {
+    if !resp.status().is_success() {
+        // TODO: Return an error instead of panicking.
+        panic!("Bad request response.");
+    }
+
     let headers = resp.headers().clone();
 
     let ct_len = headers.get::<ContentLength>().map(|ct_len| **ct_len);
@@ -35,6 +43,7 @@ fn download_into(dir: &str, file_title: &str, url: &str) -> Result<String> {
     ct_type.map(|x| info!("Content Type: {}", x));
 
     // This could be prettier.
+    // Determine the file extension from the http content-type header.
     let ext = if let Some(t) = ct_type {
         let mime = mime_guess::get_extensions(t.type_().as_ref(), t.subtype().as_ref());
         if let Some(m) = mime {
@@ -63,19 +72,19 @@ fn download_into(dir: &str, file_title: &str, url: &str) -> Result<String> {
         rng.gen::<usize>()
     );
 
+    // Save requested content into the file.
     save_io(&out_file, &mut resp, ct_len)?;
 
     // Construct the desired path.
     let target = format!("{}/{}.{}", dir, file_title, ext);
-        // Rename/move the tempfile into a permanent place.
+    // Rename/move the tempfile into a permanent place upon success.
     rename(out_file, &target)?;
     info!("Downloading of {} completed succesfully.", &target);
-        return Ok(target);
-    }
-    // Ok(String::from(""))
-    panic!("Bad request response.");
+    Ok(target)
 }
 
+// TODO: Write unit-tests.
+/// Handles the I/O of fetching a remote file and saving into a Buffer and A File.
 fn save_io(file: &str, resp: &mut reqwest::Response, content_lenght: Option<u64>) -> Result<()> {
     info!("Downloading into: {}", file);
     let chunk_size = match content_lenght {
@@ -116,6 +125,7 @@ pub fn get_episode(connection: &Database, ep: &mut Episode, download_folder: &st
             return Ok(());
         }
 
+        // If the path is not valid, then set it to None.
         ep.set_local_uri(None);
         ep.save(connection)?;
     };
@@ -134,7 +144,10 @@ pub fn get_episode(connection: &Database, ep: &mut Episode, download_folder: &st
 }
 
 pub fn cache_image(pd: &Podcast) -> Option<String> {
-    if pd.image_uri().is_some() {
+    if pd.image_uri().is_none() {
+        return None;
+    }
+
     let url = pd.image_uri().unwrap().to_owned();
     if url == "" {
         return None;
@@ -170,15 +183,13 @@ pub fn cache_image(pd: &Podcast) -> Option<String> {
     let dlpath = download_into(&download_fold, "cover", &url);
     if let Ok(path) = dlpath {
         info!("Cached img into: {}", &path);
-            return Some(path);
+        Some(path)
     } else {
         error!("Failed to get feed image.");
         error!("Error: {}", dlpath.unwrap_err());
-            return None;
-        };
-    }
         None
     }
+}
 
 #[cfg(test)]
 mod tests {