Check extensions case-invariant

Ran clippy and linted some of the logic.

src/main.rs

@@ -113,7 +113,7 @@ async fn get_image(
     req: web::Query<ThumbnailRequest>,
 ) -> impl Responder {
     if let Some(path) = is_valid_path(&req.path) {
-        if let Some(_) = req.size {
+        if req.size.is_some() {
             let thumbs = dotenv::var("THUMBNAILS").unwrap();
             let thumb_path = Path::new(&thumbs).join(path.file_name().unwrap());
 
@@ -123,12 +123,10 @@ async fn get_image(
             } else {
                 HttpResponse::NotFound().finish()
             }
-        } else {
-            if let Ok(file) = NamedFile::open(path) {
+        } else if let Ok(file) = NamedFile::open(path) {
                 file.into_response(&request).unwrap()
-            } else {
-                HttpResponse::NotFound().finish()
-            }
+        } else {
+            HttpResponse::NotFound().finish()
         }
     } else {
         HttpResponse::BadRequest().finish()
@@ -186,7 +184,7 @@ async fn create_thumbnails() {
         .read_dir()
         .expect("Error reading thumbnail directory")
         .collect();
-    if t.len() > 0 {
+    if !t.is_empty() {
         println!("Skipping thumbs");
         return;
     }
@@ -200,9 +198,12 @@ async fn create_thumbnails() {
         .filter_map(|entry| entry.ok())
         .filter(|entry| {
             println!("{:?}", entry.path());
-            match entry.path().extension() {
-                Some(ext) if ext == "jpg" || ext == "jpeg" || ext == "png" => true,
-                _ => false,
+            if let Some(ext) = entry.path().extension().and_then(|ext| {
+                ext.to_str().map(|ext| ext.to_lowercase())
+            }) {
+                ext == "jpg" || ext == "jpeg" || ext == "png"
+            } else {
+                false
             }
         })
         .map(|entry| (image::open(entry.path()), entry.path().to_path_buf()))