//! The signed-in shell: left sidebar (folders + manage tabs) and the topbar.

use crate::i18n;
use leptos::prelude::*;
use wasm_bindgen_futures::spawn_local;

use crate::api::{self, Entry, Me};
use crate::components::icon::Icon;
use crate::components::logo::Logo;
use crate::components::toast::{ToastMsg, ToastView, provide_toast, show_error};
use crate::icons::IconName;
use crate::router::{Location, Section, navigate};
use crate::views::admin::{SettingsView, UsersView};
use crate::views::browser::{Browser, SelectionActions, effective_root};
use crate::views::dialogs::{Dialog, DialogView};
use crate::views::file_view::{FileView, FileViewActions, FileViewContent, FileViewTitle};
use crate::views::search::SearchView;
use crate::views::shares::SharesView;

/// Whether the signed-in user has admin rights.
fn is_admin_of(me: &Option<Me>) -> bool {
    me.as_ref()
        .and_then(|m| m.user.as_ref())
        .is_some_and(|u| u.is_admin)
}

/// Re-fetch this session's `/me`. For things that can change the session
/// outside of the current view: the sidebar's refresh button, or saving a
/// user that is the current user.
pub fn refresh_me(set_me: WriteSignal<Option<Me>>, toast: ToastMsg) {
    spawn_local(async move {
        match api::me().await {
            Ok(m) => set_me.set(Some(m)),
            Err(e) => show_error(toast, e.to_string()),
        }
    });
}

#[component]
pub fn ShellView(
    me: ReadSignal<Option<Me>>,
    set_me: WriteSignal<Option<Me>>,
    set_phase: WriteSignal<crate::app::AuthPhase>,
    loc: ReadSignal<Location>,
    theme: ReadSignal<crate::theme::Theme>,
    set_theme: WriteSignal<crate::theme::Theme>,
) -> impl IntoView {
    let toast = provide_toast();
    // True while the off-canvas sidebar is open (narrow screens only).
    let (nav_open, set_nav_open) = signal(false);
    // A file opened in the full-page view (preview / editor / "no preview");
    // the top bar doubles as its header.
    let (file_view, set_file_view) = signal(Option::<FileView>::None);
    // The open editor stores its save callback here for the top-bar button.
    let (save_cb, set_save_cb) = signal(Option::<Callback<()>>::None);
    // The open editor's guarded close request (unsaved-changes prompt).
    let (close_cb, set_close_cb) = signal(Option::<Callback<()>>::None);
    // The editor's state, shared with the top bar (dirty dot, Save button).
    let (dirty, set_dirty) = signal(false);
    let (saving, set_saving) = signal(false);
    // The browser's fetch, exposed so the editor can re-list after a save.
    let (browser_refresh, set_browser_refresh) = signal(Option::<Callback<()>>::None);
    let topbar_ref = NodeRef::<leptos::html::Header>::new();
    // The single selected entry in the file browser; its action buttons live
    // in the top bar's top right. `None` shows the empty-area actions.
    let (selected, set_selected) = signal(Option::<Entry>::None);
    // Dialogs are rendered here, above everything (used by both the browser
    // and the top bar's selection actions).
    let (dialog, set_dialog) = signal(Option::<Dialog>::None);
    // Long-lived owner for callbacks created inside short-lived scopes
    // (top-bar selection actions).
    let shell_owner = Owner::current().unwrap();

    // Navigating (new folder, root, section) invalidates the selection.
    Effect::new(move |_| {
        let _ = loc.get();
        set_selected.set(None);
    });

    let close_file = Callback::new(move |_| {
        set_file_view.set(None);
        set_save_cb.set(None);
        set_close_cb.set(None);
        set_dirty.set(false);
        set_saving.set(false);
    });

    // Escape closes previews and the "no preview" view. The editor handles
    // Escape itself (it asks first when there are unsaved changes).
    {
        let fv = file_view;
        let cf = close_file;
        crate::util::owned_window_listener(
            leptos::ev::keydown,
            move |ev: web_sys::KeyboardEvent| {
                if ev.key() != "Escape" {
                    return;
                }
                if fv
                    .get()
                    .is_some_and(|v| matches!(v, FileView::Preview(..) | FileView::Unsupported(_)))
                {
                    cf.run(());
                }
            },
        );
    }

    // A non-admin cannot open the admin sections. If the URL points at one
    // (deep link, hand-typed, or left over from a demotion), redirect to the
    // files view so the URL, the content fallback, and the sidebar highlight
    // all agree.
    {
        let me2 = me;
        let loc2 = loc;
        Effect::new(move |_| {
            let Some(m) = me2.get() else {
                return;
            };
            let admin = m.user.as_ref().is_some_and(|u| u.is_admin);
            if admin {
                return;
            }
            let section = loc2.get().section;
            if section == Section::Users {
                navigate(&Location::root());
            }
        });
    }

    let on_logout = move |_| {
        spawn_local(async move {
            let _ = api::logout().await;
            set_me.set(None);
            set_phase.set(crate::app::AuthPhase::Login);
        });
    };

    // Navigate to a manage section (each has its own URL) and, on narrow
    // screens, close the off-canvas sidebar.
    let open_section = move |section: Section| {
        set_nav_open.set(false);
        navigate(&Location {
            root_id: None,
            path: Vec::new(),
            share_token: None,
            section,
        });
    };

    view! {
        <div
            class=move || {
                if file_view.get().is_some() {
                    "layout file-mode".to_string()
                } else {
                    "layout".to_string()
                }
            }
        >
            <header class="topbar" node_ref=topbar_ref>
                <div class="topbar-left">
                    <button
                        class="icon-btn nav-toggle"
                        title={i18n::tr(i18n::k::MENU)}
                        aria-label={i18n::tr(i18n::k::OPEN_MENU)}
                        on:click=move |_| set_nav_open.update(|v| *v = !*v)
                    >
                        <Icon name=IconName::Menu class="ic-btn".to_string()/>
                    </button>
                    {move || match file_view.get() {
                        Some(ref v) => view! {
                            // The brand stays in file mode as an icon-only
                            // link to the root folder, left of the file title.
                            <a class="brand brand-icon" href="#/">
                                <Logo/>
                            </a>
                            <FileViewTitle view=v.clone() dirty=dirty/>
                        }
                        .into_view()
                        .into_any(),
                        None => view! {
                            <a class="brand" href="#/"><Logo/><span class="brand-name">"filebrowser-ng"</span></a>
                        }
                        .into_view()
                        .into_any(),
                    }}
                </div>
                {move || {
                    if let Some(v) = file_view.get() {
                        view! {
                            <FileViewActions
                                view=v
                                saving=saving
                                dirty=dirty
                                save_cb=save_cb
                                close_cb=close_cb
                                show_close=true
                                on_close=close_file
                                toast=toast
                            />
                        }
                        .into_view()
                        .into_any()
                    } else if loc.get().section == Section::Files {
                        let refresh = browser_refresh
                            .get()
                            .unwrap_or_else(|| Callback::new(move |_| {}));
                        view! {
                            <SelectionActions
                                me=me
                                loc=loc
                                selected=selected
                                open_file=set_file_view
                                refresh=refresh
                                toast=toast
                                set_dialog=set_dialog
                                owner=shell_owner.clone()
                                topbar_ref=topbar_ref
                            />
                        }
                        .into_view()
                        .into_any()
                    } else {
                        view! {}.into_any()
                    }
                }}
            </header>
            {move || {
                if nav_open.get() {
                    view! {
                        <div class="nav-backdrop" on:click=move |_| set_nav_open.set(false)></div>
                    }
                    .into_view()
                    .into_any()
                } else {
                    view! {}.into_any()
                }
            }}
            <div class="body-row">
                {move || {
                    if file_view.get().is_none() {
                        view! {
                            <aside
                                class="sidebar"
                                class:open=move || nav_open.get()
                            >
                    <nav class="nav">
                    {move || {
                        let Some(u) = me.get().and_then(|m| m.user) else {
                            return {
                                view! {}.into_any()
                            };
                        };
                        view! {
                            <div class="sidebar-user">{u.name.clone()}</div>
                        }
                        .into_view()
                        .into_any()
                    }}
                    <div class="nav-section">
                        <div class="nav-section-head">
                            <div class="nav-section-label">{i18n::tr(i18n::k::FILES)}</div>
                            <button
                                class="icon-btn icon-btn-sm nav-section-refresh"
                                title={i18n::tr(i18n::k::REFRESH_FOLDERS)}
                                on:click=move |_| refresh_me(set_me, toast)
                            >
                                <Icon name=IconName::Refresh class="ic-btn".to_string()/>
                            </button>
                        </div>
                        <button
                            class="nav-tab"
                            class:active=move || loc.get().section == Section::Search
                            on:click=move |_| open_section(Section::Search)
                        >
                            <Icon name=IconName::Search class="ic-tab".to_string()/>
                            <span class="nav-tab-name">{i18n::tr(i18n::k::SEARCH)}</span>
                        </button>
                        {move || {
                            let Some(m) = me.get() else {
                                return {
                                    view! {}.into_any()
                                };
                            };
                            let cur_root = effective_root(&m.roots, &loc.get()).map(|r| r.id);
                            m.roots
                                .iter()
                                .map(|r| {
                                    let id = r.id;
                                    let name = r.name.clone();
                                    let path = r.path.clone();
                                    let ro = !r.mode.is_writable();
                                    view! {
                                        <button
                                            class="nav-tab"
                                            class:active=move || {
                                                loc.get().section == Section::Files
                                                    && cur_root == Some(id)
                                            }
                                            title=move || {
                                                if path == "." {
                                                    "/".to_string()
                                                } else {
                                                    path.clone()
                                                }
                                            }
                                            on:click=move |_| {
                                                set_nav_open.set(false);
                                                navigate(&Location {
                                                    root_id: Some(id),
                                                    path: vec![],
                                                    share_token: None,
                                                    section: Section::Files,
                                                });
                                            }
                                        >
                                            <Icon name=IconName::Folder class="ic-tab".to_string()/>
                                            <span class="nav-tab-name">{name}</span>
                                            {move || {
                                                if ro {
                                                    view! { <span class="nav-tab-note">"ro"</span> }
                                                        .into_view()
                                                        .into_any()
                                                } else {
                                                    view! {}.into_any()
                                                }
                                            }}
                                        </button>
                                    }
                                })
                                .collect::<Vec<_>>()
                                .into_view()
                                .into_any()
                        }}
                    </div>
                    <div class="nav-section">
                        <div class="nav-section-label">{i18n::tr(i18n::k::MANAGE)}</div>
                        <button
                            class="nav-tab"
                            class:active=move || loc.get().section == Section::Shares
                            on:click=move |_| open_section(Section::Shares)
                        >
                            <Icon name=IconName::Share class="ic-tab".to_string()/>
                            <span class="nav-tab-name">{i18n::tr(i18n::k::SHARES)}</span>
                        </button>
                        <Show when=move || is_admin_of(&me.get())>
                            <button
                                class="nav-tab"
                                class:active=move || loc.get().section == Section::Users
                                on:click=move |_| open_section(Section::Users)
                            >
                                <Icon name=IconName::User class="ic-tab".to_string()/>
                                <span class="nav-tab-name">{i18n::tr(i18n::k::USERS)}</span>
                            </button>
                        </Show>
                        <button
                            class="nav-tab"
                            class:active=move || loc.get().section == Section::Settings
                            on:click=move |_| open_section(Section::Settings)
                        >
                            <Icon name=IconName::Settings class="ic-tab".to_string()/>
                            <span class="nav-tab-name">{i18n::tr(i18n::k::SETTINGS)}</span>
                        </button>
                    </div>
                        </nav>
                        <div class="sidebar-footer">
                            <button
                                class="nav-tab sidebar-action"
                                title=move || i18n::t_fmt(i18n::k::THEME_TITLE, i18n::t(theme.get().name_key()))
                                on:click=move |_| {
                                    let next = theme.get().next();
                                    set_theme.set(next);
                                    next.store();
                                    next.apply();
                                }
                            >
                                {move || {
                                    view! {
                                        <Icon name=theme.get().icon() class="ic-tab".to_string()/>
                                    }
                                }}
                                <span class="nav-tab-name">{move || i18n::t(theme.get().name_key()).to_string()}</span>
                            </button>
                            <button
                                class="nav-tab sidebar-action logout"
                                title={i18n::tr(i18n::k::LOG_OUT)}
                                on:click=move |_| on_logout(())
                            >
                                <Icon name=IconName::Logout class="ic-tab".to_string()/>
                                <span class="nav-tab-name">{i18n::tr(i18n::k::LOG_OUT)}</span>
                            </button>
                            <div class="sidebar-version">
                                {format!("filebrowser-ng v{}", env!("CARGO_PKG_VERSION"))}
                            </div>
                        </div>
                            </aside>
                        }
                        .into_view()
                        .into_any()
                    } else {
                        view! {}.into_any()
                    }
                }}
                <main class="content" class:file-open=move || file_view.get().is_some()>
                    {move || {
                        let admin = is_admin_of(&me.get());
                        match loc.get().section {
                            Section::Files => view! {
                                <Browser
                                    me=me
                                    set_me=set_me
                                    loc=loc
                                    open_file=set_file_view
                                    set_browser_refresh=set_browser_refresh
                                    selected=selected
                                    set_selected=set_selected
                                    set_dialog=set_dialog
                                    dialog=dialog
                                    file_view=file_view
                                />
                            }
                            .into_view()
                            .into_any(),
                            Section::Search => view! {
                                <SearchView
                                    me=me
                                    open_file=set_file_view
                                    file_view=file_view
                                />
                            }
                            .into_view()
                            .into_any(),
                            Section::Shares => view! { <SharesView/> }
                                .into_view()
                                .into_any(),
                            Section::Users if admin => {
                                view! { <UsersView me=me set_me=set_me/> }.into_view().into_any()
                            }
                            Section::Settings => view! {
                                <SettingsView me=me set_me=set_me/>
                            }
                            .into_view()
                            .into_any(),
                            // Not an admin anymore (e.g. permissions changed):
                            // fall back to the files view.
                            _ => view! {
                                <Browser
                                    me=me
                                    set_me=set_me
                                    loc=loc
                                    open_file=set_file_view
                                    set_browser_refresh=set_browser_refresh
                                    selected=selected
                                    set_selected=set_selected
                                    set_dialog=set_dialog
                                    dialog=dialog
                                    file_view=file_view
                                />
                            }
                            .into_view()
                            .into_any(),
                        }
                    }}
                    {move || match file_view.get() {
                        Some(v) => {
                            let refresh = browser_refresh
                                .get()
                                .unwrap_or_else(|| Callback::new(move |_| {}));
                            view! {
                                <FileViewContent
                                    view=v
                                    register_save=set_save_cb
                                    register_close=set_close_cb
                                    dirty=dirty
                                    set_dirty=set_dirty
                                    set_saving=set_saving
                                    close=close_file
                                    toast=toast
                                    refresh=refresh
                                />
                            }
                            .into_view()
                            .into_any()
                        }
                        None => view! {}.into_any(),
                    }}
                </main>
            </div>
            <ToastView toast=toast/>
            <DialogView dialog=dialog set_dialog=set_dialog/>
        </div>
    }
}