inline code documentation completed to satisfactory level

src/update_message.rs

@@ -1,7 +1,21 @@
+//! This file deals with updating the actual message, including proper formatting. 
+use log::{debug, trace};
 use mpris::{MetadataValue};
 
 use crate::structs::{config::Config, data::Data};
 
+/// This function converts a given MetadataValue to a String.
+/// Note that two types of the MetadataValue enum are currently unsupported:
+/// Both the Map and Unsupported types currently lead the program to panic!
+/// The HashMap because I honestly don't know when a metadata value would be encoded as such (and am too lazy to dig through the crate's source code),
+/// The Unsupported type should be self-explanatory.
+/// 
+/// Input:
+/// v: MetadataValue to convert.
+/// sep: seperation character to insert between entries of a Vec.
+/// 
+/// Output:
+/// String representing the input MetadataValue.
 fn value_to_string(v: &MetadataValue, sep: char) -> String {
   match v {
     MetadataValue::String(v) => v.to_string(),
@@ -28,6 +42,16 @@ fn value_to_string(v: &MetadataValue, sep: char) -> String {
   }
 }
 
+/// This function converts one specific instance of MetadataValue to an appropriate String.
+/// It deals with the xesam:userRating type. This is a float (0.0 <= v <= 1.0), but should be represented on a scale fron 0 to 10 (according to me).
+/// As such, it converts the float value to a visually appealing 5-symbol string.
+/// 
+/// Input:
+/// r: MetadataValue, should be of the enum type f64 (unchecked).
+/// str: Vec containing precomputed rating strings to select from.
+/// 
+/// Output:
+/// Some(String) if a rating exists, None otherwise.
 fn rating_to_string(r: Option<&MetadataValue>, str: &Vec<String>) -> Option<String> {
   match r {
     Some(rating) => {
@@ -38,15 +62,25 @@ fn rating_to_string(r: Option<&MetadataValue>, str: &Vec<String>) -> Option<Stri
 
         Some(str[i as usize].clone()) //TODO: still inefficient. would be better to note the idx and load it in print_text 
       } else {
+        debug!("failed to convert MetadataValue to f64!");
         None
       }
     },
     None => {
+      trace!("no userRating MetadataValue found!");
       None
     },
   }
 }
 
+/// This higher level function updates the to be output Hashmap of strings.
+/// It does so by querying each metadata field in config to the current player, then updating the Hashmap in Data with the new value(s).
+/// "xesam:userRating" is treated separately, due to requiring a different output format.
+/// 
+/// Input:
+/// cfg: Config struct for the program. Contains the wanted metadata fields.
+/// data: mutable Data struct for the program. Its' Hashmap containing strings is updated.
+/// ratings: Vec of precomputed rating strings.
 pub fn update_message(cfg: &Config, data: &mut Data, ratings: &Vec<String>) {
   if let Some(player) = &data.current_player {
     if let Ok(meta) = player.get_metadata() {