use std::cell::RefCell;
use std::rc::Rc;
use base64ct::{Base64, Encoding};
use serde::de::DeserializeOwned;
use serde::Serialize;
use crate::functional::{Hook, HookContext, PreparedState};
use crate::suspense::SuspensionResult;
pub(super) struct TransitiveStateBase<T, D, F>
where
D: Serialize + DeserializeOwned + PartialEq + 'static,
T: Serialize + DeserializeOwned + 'static,
F: 'static + FnOnce(Rc<D>) -> T,
{
pub state_fn: RefCell<Option<F>>,
pub deps: Rc<D>,
}
impl<T, D, F> PreparedState for TransitiveStateBase<T, D, F>
where
D: Serialize + DeserializeOwned + PartialEq + 'static,
T: Serialize + DeserializeOwned + 'static,
F: 'static + FnOnce(Rc<D>) -> T,
{
fn prepare(&self) -> String {
let f = self.state_fn.borrow_mut().take().unwrap();
let state = f(self.deps.clone());
let state = bincode::serde::encode_to_vec(
(Some(&state), Some(&*self.deps)),
bincode::config::standard(),
)
.expect("failed to prepare state");
Base64::encode_string(&state)
}
}
#[doc(hidden)]
pub fn use_transitive_state<T, D, F>(
deps: D,
f: F,
) -> impl Hook<Output = SuspensionResult<Option<Rc<T>>>>
where
D: Serialize + DeserializeOwned + PartialEq + 'static,
T: Serialize + DeserializeOwned + 'static,
F: 'static + FnOnce(Rc<D>) -> T,
{
struct HookProvider<T, D, F>
where
D: Serialize + DeserializeOwned + PartialEq + 'static,
T: Serialize + DeserializeOwned + 'static,
F: 'static + FnOnce(Rc<D>) -> T,
{
deps: D,
f: F,
}
impl<T, D, F> Hook for HookProvider<T, D, F>
where
D: Serialize + DeserializeOwned + PartialEq + 'static,
T: Serialize + DeserializeOwned + 'static,
F: 'static + FnOnce(Rc<D>) -> T,
{
type Output = SuspensionResult<Option<Rc<T>>>;
fn run(self, ctx: &mut HookContext) -> Self::Output {
let f = self.f;
ctx.next_prepared_state(move |_re_render, _| -> TransitiveStateBase<T, D, F> {
TransitiveStateBase {
state_fn: Some(f).into(),
deps: self.deps.into(),
}
});
Ok(None)
}
}
HookProvider::<T, D, F> { deps, f }
}