/*
    This file is part of jellything (https://codeberg.org/metamuffin/jellything)
    which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
    Copyright (C) 2025 metamuffin <metamuffin.org>
*/
use crate::{
    routes::{
        locale::lang_from_request,
        ui::{
            account::{
                rocket_uri_macro_r_account_login, rocket_uri_macro_r_account_logout,
                rocket_uri_macro_r_account_register, session::Session,
                settings::rocket_uri_macro_r_account_settings,
            },
            admin::rocket_uri_macro_r_admin_dashboard,
            browser::rocket_uri_macro_r_all_items,
            node::rocket_uri_macro_r_library_node,
            search::rocket_uri_macro_r_search,
            stats::rocket_uri_macro_r_stats,
        },
    },
    uri,
};
use futures::executor::block_on;
use jellybase::{
    locale::{tr, Language},
    CONF,
};
use jellycommon::user::Theme;
use jellycommon::NodeID;
use jellyimport::is_importing;
use markup::{DynRender, Render, RenderAttributeValue};
use rocket::{
    http::ContentType,
    response::{self, Responder},
    Request, Response,
};
use std::{borrow::Cow, io::Cursor, sync::LazyLock};

static LOGO_ENABLED: LazyLock<bool> = LazyLock::new(|| CONF.asset_path.join("logo.svg").exists());

pub struct TrString<'a>(Cow<'a, str>);
impl Render for TrString<'_> {
    fn render(&self, writer: &mut impl std::fmt::Write) -> std::fmt::Result {
        self.0.as_str().render(writer)
    }
}
impl RenderAttributeValue for TrString<'_> {
    fn is_none(&self) -> bool {
        false
    }
    fn is_true(&self) -> bool {
        false
    }
    fn is_false(&self) -> bool {
        false
    }
}

pub fn escape(str: &str) -> String {
    let mut o = String::with_capacity(str.len());
    let mut last = 0;
    for (index, byte) in str.bytes().enumerate() {
        if let Some(esc) = match byte {
            b'<' => Some("&lt;"),
            b'>' => Some("&gt;"),
            b'&' => Some("&amp;"),
            b'"' => Some("&quot;"),
            _ => None,
        } {
            o += &str[last..index];
            o += esc;
            last = index + 1;
        }
    }
    o += &str[last..];
    o
}

pub fn trs<'a>(lang: &Language, key: &str) -> TrString<'a> {
    TrString(tr(*lang, key))
}

markup::define! {
    Layout<'a, Main: Render>(title: String, main: Main, class: &'a str, session: Option<Session>, lang: Language) {
        @markup::doctype()
        html {
            head {
                title { @title " - " @CONF.brand }
                meta[name="viewport", content="width=device-width, initial-scale=1.0"];
                link[rel="stylesheet", href="/assets/style.css"];
                script[src="/assets/bundle.js"] {}
            }
            body[class=class] {
                nav {
                    h1 { a[href=if session.is_some() {"/home"} else {"/"}] { @if *LOGO_ENABLED { img.logo[src="/assets/logo.svg"]; } else { @CONF.brand } } } " "
                    @if let Some(_) = session {
                        a.library[href=uri!(r_library_node("library"))] { @trs(lang, "nav.root") } " "
                        a.library[href=uri!(r_all_items())] { @trs(lang, "nav.all") } " "
                        a.library[href=uri!(r_search(None::<&'static str>, None::<usize>))] { @trs(lang, "nav.search") } " "
                        a.library[href=uri!(r_stats())] { @trs(lang, "nav.stats") } " "
                    }
                    @if is_importing() { span.warn { "Library database is updating..." } }
                    div.account {
                        @if let Some(session) = session {
                            span { "Logged in as " } span.username { @session.user.display_name } " "
                            @if session.user.admin {
                                a.admin.hybrid_button[href=uri!(r_admin_dashboard())] { p {@trs(lang, "nav.admin")} } " "
                            }
                            a.settings.hybrid_button[href=uri!(r_account_settings())] { p {@trs(lang, "nav.settings")} } " "
                            a.logout.hybrid_button[href=uri!(r_account_logout())] { p {@trs(lang, "nav.logout")} }
                        } else {
                            a.register.hybrid_button[href=uri!(r_account_register())] { p {@trs(lang, "nav.register")} } " "
                            a.login.hybrid_button[href=uri!(r_account_login())] { p {@trs(lang, "nav.login")} }
                        }
                    }
                }
                #main { @main }
                footer {
                    p { @CONF.brand " - " @CONF.slogan " | powered by " a[href="https://codeberg.org/metamuffin/jellything"]{"Jellything"} }
                }
            }
        }
    }

    FlashDisplay(flash: Option<Result<String, String>>) {
        @if let Some(flash) = &flash {
            @match flash {
                Ok(mesg) => { section.message { p.success { @mesg } } }
                Err(err) => { section.message { p.error { @err } } }
            }
        }
    }
}

pub type DynLayoutPage<'a> = LayoutPage<markup::DynRender<'a>>;

pub struct LayoutPage<T> {
    pub title: String,
    pub class: Option<&'static str>,
    pub content: T,
}

impl Default for LayoutPage<DynRender<'_>> {
    fn default() -> Self {
        Self {
            class: None,
            content: markup::new!(),
            title: String::new(),
        }
    }
}

impl<'r, Main: Render> Responder<'r, 'static> for LayoutPage<Main> {
    fn respond_to(self, req: &'r Request<'_>) -> response::Result<'static> {
        // TODO blocking the event loop here. it seems like there is no other way to
        // TODO offload this, since the guard references `req` which has a lifetime.
        // TODO therefore we just block. that is fine since the database is somewhat fast.
        let lang = lang_from_request(&req);
        let session = block_on(req.guard::<Option<Session>>()).unwrap();
        let mut out = String::new();
        Layout {
            main: self.content,
            title: self.title,
            class: &format!(
                "{} theme-{:?}",
                self.class.unwrap_or(""),
                session
                    .as_ref()
                    .map(|s| s.user.theme)
                    .unwrap_or(Theme::Dark)
            ),
            session,
            lang,
        }
        .render(&mut out)
        .unwrap();

        Response::build()
            .header(ContentType::HTML)
            .streamed_body(Cursor::new(out))
            .ok()
    }
}