use dioxus::prelude::*;
use dioxus_free_icons::icons::bs_icons::{BsList, BsX};
use dioxus_free_icons::Icon;

use crate::components::sidebar::Sidebar;
use crate::i18n::{t, tw, Locale};
use crate::infrastructure::auth_check::check_auth;
use crate::models::{AuthInfo, ServiceUrlsContext};
use crate::Route;

/// Application shell layout that wraps all authenticated pages.
///
/// Calls [`check_auth`] on mount to fetch the current user's session.
/// If unauthenticated, redirects to `/auth`. Otherwise renders the
/// sidebar with real user data and the active child route.
#[component]
pub fn AppShell() -> Element {
    let locale = use_context::<Signal<Locale>>();
    let mut mobile_menu_open = use_signal(|| false);

    // use_resource memoises the async call and avoids infinite re-render
    // loops that use_effect + spawn + signal writes can cause.
    #[allow(clippy::redundant_closure)]
    let auth = use_resource(move || check_auth());

    // Clone the inner value out of the Signal to avoid holding the
    // borrow across the rsx! return (Dioxus lifetime constraint).
    let auth_snapshot: Option<Result<AuthInfo, ServerFnError>> = auth.read().clone();

    match auth_snapshot {
        Some(Ok(info)) if info.authenticated => {
            // Provide developer tool URLs as context so child pages
            // can read them without prop-drilling through layouts.
            use_context_provider(|| {
                Signal::new(ServiceUrlsContext {
                    langgraph_url: info.langgraph_url.clone(),
                    langflow_url: info.langflow_url.clone(),
                    langfuse_url: info.langfuse_url.clone(),
                })
            });

            let menu_open = *mobile_menu_open.read();
            let sidebar_cls = if menu_open {
                "sidebar sidebar--open"
            } else {
                "sidebar"
            };

            rsx! {
                div { class: "app-shell",
                    // Mobile top bar (visible only on small screens via CSS)
                    header { class: "mobile-header",
                        button {
                            class: "mobile-menu-btn",
                            onclick: move |_| {
                                let current = *mobile_menu_open.read();
                                mobile_menu_open.set(!current);
                            },
                            if menu_open {
                                Icon { icon: BsX, width: 24, height: 24 }
                            } else {
                                Icon { icon: BsList, width: 24, height: 24 }
                            }
                        }
                        span { class: "mobile-header-title", "CERTifAI" }
                    }
                    // Backdrop overlay when sidebar is open on mobile
                    if menu_open {
                        div {
                            class: "sidebar-backdrop",
                            onclick: move |_| mobile_menu_open.set(false),
                        }
                    }
                    Sidebar {
                        email: info.email,
                        name: info.name,
                        avatar_url: info.avatar_url,
                        librechat_url: info.librechat_url,
                        compliance_scanner_url: info.compliance_scanner_url,
                        class: sidebar_cls,
                        on_nav: move |_| mobile_menu_open.set(false),
                    }
                    main { class: "main-content", Outlet::<Route> {} }
                }
            }
        }
        Some(Ok(_)) => {
            // Not authenticated -- redirect to login.
            let nav = navigator();
            nav.push(NavigationTarget::<Route>::External("/auth".into()));
            rsx! {
                div { class: "app-shell loading",
                    p { {t(*locale.read(), "auth.redirecting_login")} }
                }
            }
        }
        Some(Err(e)) => {
            let msg = e.to_string();
            let error_text = tw(*locale.read(), "auth.auth_error", &[("msg", &msg)]);
            rsx! {
                div { class: "auth-error",
                    p { {error_text} }
                    a { href: "/auth", {t(*locale.read(), "common.login")} }
                }
            }
        }
        None => {
            // Still loading.
            rsx! {
                div { class: "app-shell loading",
                    p { {t(*locale.read(), "common.loading")} }
                }
            }
        }
    }
}