use adw::{prelude::*, subclass::prelude::*};
use gettextrs::gettext;
use gtk::{self, glib, glib::clone, CompositeTemplate};
use matrix_sdk::{
    config::RequestConfig, sanitize_server_name, Client, ClientBuildError, ClientBuilder,
};
use ruma::api::client::discovery::get_supported_versions;
use tracing::warn;
use url::Url;

use super::Login;
use crate::{
    components::{LoadingButton, OfflineBanner},
    gettext_f,
    prelude::*,
    spawn_tokio, toast,
    utils::BoundObjectWeakRef,
};

mod imp {
    use glib::subclass::InitializingObject;

    use super::*;

    #[derive(Debug, Default, CompositeTemplate, glib::Properties)]
    #[template(resource = "/org/gnome/Fractal/ui/login/homeserver_page.ui")]
    #[properties(wrapper_type = super::LoginHomeserverPage)]
    pub struct LoginHomeserverPage {
        #[template_child]
        pub homeserver_entry: TemplateChild<adw::EntryRow>,
        #[template_child]
        pub homeserver_help: TemplateChild<gtk::Label>,
        #[template_child]
        pub next_button: TemplateChild<LoadingButton>,
        /// The parent `Login` object.
        #[property(get, set = Self::set_login, explicit_notify, nullable)]
        pub login: BoundObjectWeakRef<Login>,
    }

    #[glib::object_subclass]
    impl ObjectSubclass for LoginHomeserverPage {
        const NAME: &'static str = "LoginHomeserverPage";
        type Type = super::LoginHomeserverPage;
        type ParentType = adw::NavigationPage;

        fn class_init(klass: &mut Self::Class) {
            OfflineBanner::ensure_type();

            Self::bind_template(klass);
            Self::Type::bind_template_callbacks(klass);
        }

        fn instance_init(obj: &InitializingObject<Self>) {
            obj.init_template();
        }
    }

    #[glib::derived_properties]
    impl ObjectImpl for LoginHomeserverPage {}

    impl WidgetImpl for LoginHomeserverPage {
        fn grab_focus(&self) -> bool {
            self.homeserver_entry.grab_focus()
        }
    }

    impl NavigationPageImpl for LoginHomeserverPage {
        fn shown(&self) {
            self.grab_focus();
        }
    }

    impl LoginHomeserverPage {
        /// Set the parent `Login` object.
        fn set_login(&self, login: Option<&Login>) {
            let obj = self.obj();

            self.login.disconnect_signals();

            if let Some(login) = login {
                let handler = login.connect_autodiscovery_notify(clone!(
                    #[weak]
                    obj,
                    move |_| {
                        obj.update_next_state();
                        obj.update_text();
                    }
                ));

                self.login.set(login, vec![handler]);
            }

            obj.update_next_state();
            obj.update_text();
        }
    }
}

glib::wrapper! {
    /// The login page to provide the homeserver and login settings.
    pub struct LoginHomeserverPage(ObjectSubclass<imp::LoginHomeserverPage>)
        @extends gtk::Widget, adw::NavigationPage, @implements gtk::Accessible;
}

#[gtk::template_callbacks]
impl LoginHomeserverPage {
    pub fn new() -> Self {
        glib::Object::new()
    }

    /// Update the text of this page according to the current settings.
    fn update_text(&self) {
        let Some(login) = self.login() else {
            return;
        };
        let imp = self.imp();

        if login.autodiscovery() {
            imp.homeserver_entry.set_title(&gettext("Domain Name"));
            imp.homeserver_help.set_markup(&gettext(
                "The domain of your Matrix homeserver, for example gnome.org",
            ));
        } else {
            imp.homeserver_entry.set_title(&gettext("Homeserver URL"));
            imp.homeserver_help.set_markup(&gettext_f(
                // Translators: Do NOT translate the content between '{' and '}', this is a
                // variable name.
                "The URL of your Matrix homeserver, for example {address}",
                &[(
                    "address",
                    "<span segment=\"word\">https://gnome.modular.im</span>",
                )],
            ));
        }
    }

    /// Reset this page.
    pub fn clean(&self) {
        let imp = self.imp();
        imp.homeserver_entry.set_text("");
        imp.next_button.set_is_loading(false);
        self.update_next_state();
    }

    /// Whether the current state allows to go to the next step.
    fn can_go_next(&self) -> bool {
        let Some(login) = self.login() else {
            return false;
        };
        let homeserver = self.imp().homeserver_entry.text();

        if login.autodiscovery() {
            sanitize_server_name(homeserver.as_str()).is_ok()
        } else {
            Url::parse(homeserver.as_str()).is_ok()
        }
    }

    /// Update the state of the "Next" button.
    #[template_callback]
    fn update_next_state(&self) {
        self.imp().next_button.set_sensitive(self.can_go_next());
    }

    /// Fetch the login details of the homeserver.
    #[template_callback]
    pub async fn fetch_homeserver_details(&self) {
        self.check_homeserver().await;
    }

    /// Check if the homeserver that was entered is valid.
    pub async fn check_homeserver(&self) {
        if !self.can_go_next() {
            return;
        }

        let Some(login) = self.login() else {
            return;
        };
        let imp = self.imp();

        imp.next_button.set_is_loading(true);
        login.freeze();

        let autodiscovery = login.autodiscovery();

        let res = if autodiscovery {
            self.discover_homeserver().await
        } else {
            self.detect_homeserver().await
        };

        match res {
            Ok(client) => {
                let server_name = autodiscovery
                    .then(|| self.imp().homeserver_entry.text())
                    .and_then(|s| sanitize_server_name(&s).ok());

                login.set_domain(server_name);
                login.set_client(Some(client.clone()));

                self.homeserver_login_types(client).await;
            }
            Err(error) => {
                toast!(self, error.to_user_facing());
            }
        };

        imp.next_button.set_is_loading(false);
        login.unfreeze();
    }

    /// Try to discover the homeserver.
    async fn discover_homeserver(&self) -> Result<Client, ClientBuildError> {
        let homeserver = self.imp().homeserver_entry.text();
        let handle = spawn_tokio!(async move {
            client_builder()
                .server_name_or_homeserver_url(homeserver)
                .build()
                .await
        });

        match handle.await.unwrap() {
            Ok(client) => Ok(client),
            Err(error) => {
                warn!("Could not discover homeserver: {error}");
                Err(error)
            }
        }
    }

    /// Check if the URL points to a homeserver.
    async fn detect_homeserver(&self) -> Result<Client, ClientBuildError> {
        let homeserver = self.imp().homeserver_entry.text();
        spawn_tokio!(async move {
            let client = client_builder()
                .respect_login_well_known(false)
                .homeserver_url(homeserver)
                .build()
                .await?;

            client
                .send(get_supported_versions::Request::new(), None)
                .await?;

            Ok(client)
        })
        .await
        .unwrap()
    }

    /// Fetch the login types supported by the homeserver.
    async fn homeserver_login_types(&self, client: Client) {
        let Some(login) = self.login() else {
            return;
        };

        let handle = spawn_tokio!(async move { client.matrix_auth().get_login_types().await });

        match handle.await.unwrap() {
            Ok(res) => {
                login.set_login_types(res.flows);
                login.show_login_screen();
            }
            Err(error) => {
                warn!("Could not get available login types: {error}");
                toast!(self, "Could not get available login types");

                // Drop the client because it is bound to the homeserver.
                login.drop_client();
            }
        };
    }
}

fn client_builder() -> ClientBuilder {
    Client::builder().request_config(RequestConfig::new().retry_limit(2))
}