use super::{
    event::{Event, Sent},
    Id,
};
use crate::{channel, event::Instant, login::Login};

#[derive(Clone, Debug, Eq, PartialEq, serde::Serialize)]
pub struct Message {
    #[serde(flatten)]
    pub sent: Instant,
    pub channel: channel::Id,
    pub sender: Login,
    pub id: Id,
    pub body: String,
}

impl Message {
    fn apply(state: Option<Self>, event: Event) -> Option<Self> {
        match (state, event) {
            (None, Event::Sent(event)) => Some(event.into()),
            (Some(message), Event::Deleted(event)) if message.id == event.id => None,
            (state, event) => panic!("invalid message event {event:#?} for state {state:#?}"),
        }
    }
}

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

impl From<&Sent> for Message {
    fn from(event: &Sent) -> Self {
        event.message.clone()
    }
}

impl From<Sent> for Message {
    fn from(event: Sent) -> Self {
        event.message
    }
}