Complete the config file with default values

src/config.rs

@@ -9,10 +9,41 @@ pub struct Config {
     pub lang: Option<String>,
 }
 
+impl Config {
+    fn new() -> Self {
+        Self {
+            scheme: Some("http".to_string()),
+            port: Some(8080),
+            ..Config::default()
+        }
+    }
+
+    fn complete(a: Self) -> Self {
+        // Default config
+        let d = Config::new();
+
+        /// Return the default value if nothing is value is none
+        fn test<T>(val: Option<T>, default: Option<T>) -> Option<T> {
+            if val.is_some() {
+                val
+            } else {
+                default
+            }
+        }
+
+        Self {
+            scheme: test(a.scheme, d.scheme),
+            port: test(a.port, d.port),
+            mail: test(a.mail, d.mail),
+            lang: test(a.lang, d.lang),
+        }
+    }
+}
+
 pub fn get_config(file_path: &str) -> Config {
     match fs::read_to_string(file_path) {
         Ok(file) => match toml::from_str(&file) {
-            Ok(stored_config) => stored_config,
+            Ok(stored_config) => Config::complete(stored_config),
             Err(file_error) => {
                 panic!("Error in config file: {file_error}");
             }
@@ -20,11 +51,7 @@ pub fn get_config(file_path: &str) -> Config {
         Err(_) =>
         // No config file
         {
-            Config {
+            Config::new()
-                scheme: Some("http".to_string()),
-                port: Some(8080),
-                ..Config::default()
-            }
         }
     }
 }