regalade/app/src/full_context.rs

use std::{
    cell::{Cell, Ref, RefCell},
    collections::HashSet,
    rc::Rc,
    sync::Arc,
};

use dioxus::prelude::*;
use dioxus_router::prelude::*;
use gloo_storage::{errors::StorageError, LocalStorage, Storage};
use uuid::Uuid;

use crate::{HouseholdInfo, LoginInfo, Route};

#[derive(Props)]
pub struct RedirectorProps<'a> {
    children: Element<'a>,
}

pub struct RefreshHandle {
    run: Box<dyn FnOnce()>,
}

impl RefreshHandle {
    pub fn refresh(self) {
        (self.run)()
    }
}

#[derive(Copy, Clone)]
pub struct FullContextState<'a> {
    root: &'a ProvidedFullContext,
    value: &'a Rc<RefCell<FullContext>>,
}

impl<'a> FullContextState<'a> {
    pub fn read(&self) -> Ref<'_, FullContext> {
        self.value.borrow()
    }

    pub fn refresh(&self) {
        let r = self.root.borrow();

        r.needs_regen.set(true);
        (r.update_root)();
    }

    pub fn refresh_handle(&self) -> RefreshHandle {
        let r = self.root.clone();
        RefreshHandle {
            run: Box::new(move || {
                let root = r.borrow();
                root.needs_regen.set(true);
                (root.update_root)();
            }),
        }
    }
}

struct FullContextStateInner {
    root: ProvidedFullContext,
    value: Rc<RefCell<FullContext>>,
    scope_id: ScopeId,
}

impl Drop for FullContextStateInner {
    fn drop(&mut self) {
        let mut root = self.root.borrow_mut();
        root.consumers.remove(&self.scope_id);
    }
}

pub fn use_full_context(cx: &ScopeState) -> FullContextState {
    let state = cx.use_hook(|| {
        let scope_id = cx.scope_id();
        let root = cx
            .consume_context::<ProvidedFullContext>()
            .expect("Called use_full_context not in a full context scope");

        let mut r = root.borrow_mut();

        r.consumers.insert(scope_id);
        let value = r.value.clone();

        drop(r);
        FullContextStateInner {
            root,
            value,
            scope_id,
        }
    });

    FullContextState {
        root: &state.root,
        value: &state.value,
    }
}

pub fn use_trimmed_context(cx: &ScopeState) -> (String, Uuid) {
    let binding = use_full_context(cx);
    let ctx = binding.read();

    (ctx.login.token.clone(), ctx.household.id)
}

#[derive(Clone)]
pub struct FullContext {
    pub login: LoginInfo,
    pub household: HouseholdInfo,
}

type ProvidedFullContext = Rc<RefCell<ProvidedFullContextInner>>;

struct ProvidedFullContextInner {
    value: Rc<RefCell<FullContext>>,
    notify_any: Arc<dyn Fn(ScopeId)>,
    consumers: HashSet<ScopeId>,
    needs_regen: Cell<bool>,
    update_root: Arc<dyn Fn()>,
}

impl ProvidedFullContextInner {
    fn notify_consumers(&mut self) {
        for &consumer in &self.consumers {
            (self.notify_any)(consumer)
        }
    }
}

fn use_full_context_setter(cx: &ScopeState) {
    let gen = || {
        let login = LocalStorage::get::<LoginInfo>("token").expect("Not called in a full context");
        let household =
            LocalStorage::get::<HouseholdInfo>("household").expect("Not called in a full context");

        FullContext { login, household }
    };

    let hook = cx.use_hook(move || {
        let state = Rc::new(RefCell::new(ProvidedFullContextInner {
            value: Rc::new(RefCell::new(gen())),
            consumers: HashSet::new(),
            notify_any: cx.schedule_update_any(),
            update_root: cx.schedule_update(),
            needs_regen: Cell::new(false),
        }));

        cx.provide_context(state.clone());

        state
    });

    if hook.borrow().needs_regen.get() {
        let mut hook = (**hook).borrow_mut();
        *(*hook.value).borrow_mut() = gen();
        hook.notify_consumers();
    }
}

fn FullContextRedirectInner<'a>(cx: Scope<'a, RedirectorProps<'a>>) -> Element {
    use_full_context_setter(cx);

    cx.render(rsx! {&cx.props.children})
}

pub fn FullContextRedirect<'a>(cx: Scope<'a, RedirectorProps<'a>>) -> Element {
    let navigator = use_navigator(cx);

    let check_token = match LocalStorage::get::<LoginInfo>("token") {
        Ok(_) => true,
        Err(StorageError::KeyNotFound(_)) => {
            navigator.push(Route::Login);
            false
        }
        Err(e) => unreachable!("Could not get token: {e:?}"),
    };

    let check_household = match LocalStorage::get::<HouseholdInfo>("household") {
        Ok(_) => true,
        Err(StorageError::KeyNotFound(_)) => {
            navigator.push(Route::HouseholdSelection);
            false
        }
        Err(e) => unreachable!("Could not get household: {e:?}"),
    };

    if check_token && check_household {
        cx.render(rsx! {
            FullContextRedirectInner { &cx.props.children }
        })
    } else {
        None
    }
}