add announce command, fix multi-occurence command matching

src/utils.rs

@@ -1,4 +1,6 @@
 use std::error::Error;
+use std::borrow::Cow;
+use crate::error::GroupError;
 
 pub trait LogError {
     fn log_error<S : AsRef<str>>(self, msg: S);
@@ -14,3 +16,46 @@ impl<V, E : Error> LogError for Result<V, E> {
         }
     }
 }
+
+pub(crate) fn acct_to_server(acct : &str) -> Option<&str> {
+    acct.trim_start_matches('@').split('@').nth(1)
+}
+
+pub(crate) fn normalize_acct<'a, 'g>(acct : &'a str, group: &'g str) -> Result<Cow<'a, str>, GroupError> {
+    let acct = acct.trim_start_matches('@');
+    if acct_to_server(acct).is_some() {
+        Ok(Cow::Borrowed(acct))
+    } else {
+        if let Some(gs) = acct_to_server(group) {
+            Ok(Cow::Owned(format!("{}@{}", acct, gs)))
+        } else {
+            Err(GroupError::BadConfig(format!("Group acct {} is missing server!", group).into()))
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use crate::utils::{acct_to_server, normalize_acct};
+    use crate::error::GroupError;
+    use std::borrow::Cow;
+
+    #[test]
+    fn test_acct_to_server() {
+        assert_eq!(Some("novak"), acct_to_server("pepa@novak"));
+        assert_eq!(Some("banana.co.uk"), acct_to_server("@pepa@banana.co.uk"));
+        assert_eq!(None, acct_to_server("probably_local"));
+    }
+
+    #[test]
+    fn test_normalize_acct() {
+        assert_eq!(Ok("piggo@piggo.space".into()), normalize_acct("piggo", "betty@piggo.space"));
+        assert_eq!(Ok("piggo@piggo.space".into()), normalize_acct("@piggo", "betty@piggo.space"));
+        assert_eq!(Ok("piggo@piggo.space".into()), normalize_acct("@piggo@piggo.space", "betty@piggo.space"));
+        assert_eq!(Ok("piggo@piggo.space".into()), normalize_acct("@piggo@piggo.space", "oggip@mastodon.social"));
+        assert_eq!(Ok("piggo@piggo.space".into()), normalize_acct("piggo@piggo.space", "oggip@mastodon.social"));
+        assert_eq!(Ok("piggo@mastodon.social".into()), normalize_acct("@piggo", "oggip@mastodon.social"));
+        assert_eq!(Ok("piggo@piggo.space".into()), normalize_acct("piggo@piggo.space", "uhh"));
+        assert_eq!(Err(GroupError::BadConfig("_".into())), normalize_acct("piggo", "uhh"));
+    }
+}