made rating_icons an optional value in Config

src/update_message.rs

@@ -28,12 +28,19 @@ fn value_to_string(v: &MetadataValue, sep: char) -> String {
   }
 }
 
-fn rating_to_string(r: Option<&MetadataValue>, map: &Rating) -> Option<String> {
+fn rating_to_string(r: Option<&MetadataValue>, opt: Option<&Rating>) -> Option<String> {
+  let def = Rating::default();
+  let map: &Rating;
+  match opt {
+    Some(m) => map = m,
+    None => map = &def,
+  }
+
   match r {
     Some(rating) => {
       if let Some(f) = rating.as_f64() {
         let i = (f * 10_f64).round() as i64;
-        match i {
+        match i { //TODO: refactor this
           0 => Some(Rating::repeat(map.nil, 5)),
           1 => Some(format!("{}{}",   Rating::repeat(map.half, 1), Rating::repeat(map.nil,  4))),
           2 => Some(format!("{}{}",   Rating::repeat(map.full, 1), Rating::repeat(map.nil,  4))),
@@ -63,7 +70,7 @@ pub fn update_message(cfg: &Config, data: &mut Data) {
       for field in &cfg.metadata_fields {
         let key = field.field.clone();
         if field.field.eq("xesam:userRating") {
-          if let Some(rating_string) = rating_to_string(meta.get(&key), &cfg.rating_icons) {
+          if let Some(rating_string) = rating_to_string(meta.get(&key), cfg.rating_icons.as_ref()) {
             data.display_text.insert(key, rating_string);
           } else {
             data.display_text.remove(&key);