use std::time::Duration;

use leptos::prelude::*;
use wasm_bindgen_futures::spawn_local;

/// Context type: read/write access to the current toast.
///
/// The state is `(message, is_error)`: errors get their own styling so they
/// do not read like routine confirmations.
#[derive(Copy, Clone)]
pub struct ToastMsg(pub RwSignal<Option<(String, bool)>>);

pub fn provide_toast() -> ToastMsg {
    let toast = RwSignal::new(Option::<(String, bool)>::None);
    let t = ToastMsg(toast);
    provide_context(t);
    t
}

/// Show a toast that disappears after ~3 seconds.
pub fn show(toast: ToastMsg, msg: impl Into<String>) {
    set(toast, msg.into(), false);
}

/// Show a failure toast (danger styling).
pub fn show_error(toast: ToastMsg, msg: impl Into<String>) {
    set(toast, msg.into(), true);
}

fn set(toast: ToastMsg, msg: String, is_error: bool) {
    toast.0.set(Some((msg.clone(), is_error)));
    spawn_local(async move {
        gloo_timers::future::sleep(Duration::from_secs(3)).await;
        if toast.0.get_untracked().as_ref().map(|(m, _)| m.as_str()) == Some(msg.as_str()) {
            toast.0.set(None);
        }
    });
}

#[component]
pub fn ToastView(toast: ToastMsg) -> impl IntoView {
    view! {
        <Show when=move || toast.0.get().is_some()>
            <div class="toast" class:toast-error=move || toast.0.get().is_some_and(|(_, e)| e)>
                {move || toast.0.get().map(|(m, _)| m).unwrap_or_default()}
            </div>
        </Show>
    }
}