utils: Add a function to format codes

If the number of digits is even, inserts an empty space in the middle.

HINT: Most codes are 6 digits long, except steam of course.

src/models/account.rs

@@ -288,11 +288,8 @@ impl Account {
             provider.algorithm().into(),
             provider.digits() as u32,
         ) {
-            self.set_property(
-                "otp",
-                &format!("{:0width$}", otp, width = provider.digits() as usize),
-            )
-            .unwrap();
+            self.set_property("otp", &otp::format(otp, provider.digits() as usize))
+                .unwrap();
         };
     }
 

src/models/otp.rs

@@ -49,9 +49,18 @@ pub(crate) fn generate_hotp(
     )
 }
 
+pub(crate) fn format(code: u32, digits: usize) -> String {
+    let mut formated_code = format!("{:0width$}", code, width = digits);
+    if digits % 2 == 0 {
+        let middle = digits / 2;
+        formated_code.insert(middle, ' ');
+    }
+    formated_code
+}
+
 #[cfg(test)]
 mod tests {
-    use super::make_hotp;
+    use super::{format, make_hotp};
 
     #[test]
     fn hotp() {
@@ -70,4 +79,10 @@ mod tests {
             316439
         );
     }
+
+    #[test]
+    fn hotp() {
+        assert_eq!(format(012345, 6).unwrap(), "012 345");
+        assert_eq!(format(01234, 5).unwrap(), "01234");
+    }
 }