use super::{Subject, publish_subject::PublishSubject};
use crate::safe_lock;
use crate::utils::types::{Mutable, NecessarySendSync, Shared};
use crate::{
disposable::subscription::Subscription,
observable::Observable,
observer::{Observer, Termination},
};
use educe::Educe;
#[derive(Educe)]
#[educe(Debug, Clone)]
pub struct BehaviorSubject<'or, T, E> {
value: Shared<Mutable<T>>,
publish_subject: PublishSubject<'or, T, E>,
}
impl<T, E> BehaviorSubject<'_, T, E> {
pub fn new(value: T) -> Self {
Self {
value: Shared::new(Mutable::new(value)),
publish_subject: PublishSubject::default(),
}
}
pub fn value(&self) -> T
where
T: Clone,
{
safe_lock!(clone: self.value)
}
}
impl<'or, 'sub, T, E> Observable<'or, 'sub, T, E> for BehaviorSubject<'or, T, E>
where
T: Clone + NecessarySendSync + 'sub,
E: Clone + NecessarySendSync + 'sub,
'or: 'sub,
{
fn subscribe(
self,
mut observer: impl Observer<T, E> + NecessarySendSync + 'or,
) -> Subscription<'sub> {
if let Some(terminated) = self.terminated() {
observer.on_termination(terminated);
Subscription::default()
} else {
observer.on_next(safe_lock!(clone: self.value));
self.publish_subject.subscribe(observer)
}
}
}
impl<T, E> Observer<T, E> for BehaviorSubject<'_, T, E>
where
T: Clone + NecessarySendSync,
E: Clone + NecessarySendSync,
{
fn on_next(&mut self, value: T) {
if self.terminated().is_none() {
safe_lock!(set: self.value, value.clone());
self.publish_subject.on_next(value);
}
}
fn on_termination(self, termination: Termination<E>) {
self.publish_subject.on_termination(termination);
}
}
impl<'or, 'sub, T, E> Subject<'or, 'sub, T, E> for BehaviorSubject<'or, T, E>
where
T: Clone + NecessarySendSync + 'sub,
E: Clone + NecessarySendSync + 'sub,
'or: 'sub,
{
fn terminated(&self) -> Option<Termination<E>>
where
E: Clone,
{
self.publish_subject.terminated()
}
}