use super::{
    event::{Created, Event},
    Id,
};

// This also implements FromRequestParts (see `./extract.rs`). As a result, it
// can be used as an extractor for endpoints that want to require login, or for
// endpoints that need to behave differently depending on whether the client is
// or is not logged in.
#[derive(Clone, Debug, Eq, PartialEq, serde::Serialize)]
pub struct Login {
    pub id: Id,
    pub name: String,
    // The omission of the hashed password is deliberate, to minimize the
    // chance that it ends up tangled up in debug output or in some other chunk
    // of logic elsewhere.
}

impl Login {
    // Two reasons for this allow:
    //
    // 1. This is used to collect streams using a fold, below, which requires a type
    //    consistent with the fold, and
    // 2. It's also consistent with the other history state machine types.
    #[allow(clippy::unnecessary_wraps)]
    fn apply(state: Option<Self>, event: Event) -> Option<Self> {
        match (state, event) {
            (None, Event::Created(event)) => Some(event.into()),
            (state, event) => panic!("invalid message event {event:#?} for state {state:#?}"),
        }
    }
}

impl FromIterator<Event> for Option<Login> {
    fn from_iter<I: IntoIterator<Item = Event>>(events: I) -> Self {
        events.into_iter().fold(None, Login::apply)
    }
}

impl From<&Created> for Login {
    fn from(event: &Created) -> Self {
        event.login.clone()
    }
}

impl From<Created> for Login {
    fn from(event: Created) -> Self {
        event.login
    }
}