/*
Copyright 2023, Savanni D'Gerinel <savanni@luminescent-dreams.com>

This file is part of FitnessTrax.

FitnessTrax is free software: you can redistribute it and/or modify it under the terms of the GNU
General Public License as published by the Free Software Foundation, either version 3 of the
License, or (at your option) any later version.

FitnessTrax is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License along with FitnessTrax. If not, see <https://www.gnu.org/licenses/>.
*/
use adw::prelude::*;
use emseries::Series;
use ft_core::TraxRecord;
use gio::resources_lookup_data;
use glib::Object;
use gtk::{prelude::*, subclass::prelude::*, STYLE_PROVIDER_PRIORITY_USER};
use std::{
    cell::RefCell,
    env,
    sync::{Arc, RwLock},
};

const APP_ID_DEV: &str = "com.luminescent-dreams.fitnesstrax.dev";
const APP_ID_PROD: &str = "com.luminescent-dreams.fitnesstrax";

const RESOURCE_BASE_PATH: &str = "/com/luminescent-dreams/fitnesstrax/";

/// The real, headless application. This is where all of the logic will reside.
#[derive(Clone)]
struct App {
    database: Arc<RwLock<Option<Series<TraxRecord>>>>,
}

impl App {
    pub fn new() -> Self {
        Self {
            database: Arc::new(RwLock::new(None)),
        }
    }
}

/// This is the view to show if the application has not yet been configured. It will walk the user
/// through the most critical setup steps so that we can move on to the other views in the app.
pub struct UnconfiguredViewPrivate {}

#[glib::object_subclass]
impl ObjectSubclass for UnconfiguredViewPrivate {
    const NAME: &'static str = "UnconfiguredView";
    type Type = UnconfiguredView;
    type ParentType = gtk::Box;

    fn new() -> Self {
        Self {}
    }
}

impl ObjectImpl for UnconfiguredViewPrivate {}
impl WidgetImpl for UnconfiguredViewPrivate {}
impl BoxImpl for UnconfiguredViewPrivate {}

glib::wrapper! {
    pub struct UnconfiguredView(ObjectSubclass<UnconfiguredViewPrivate>) @extends gtk::Box, gtk::Widget;
}

impl UnconfiguredView {
    pub fn new() -> Self {
        let s: Self = Object::builder().build();

        // Replace this with the welcome screen that we set up in the fitnesstrax/unconfigured-page
        // branch.
        let label = gtk::Label::builder()
            .label("Database is not configured.")
            .build();
        s.append(&label);
        s
    }
}

/// The historical view will show a window into the main database. It will show some version of
/// daily summaries, daily details, and will provide all functions the user may need for editing
/// records.
pub struct HistoricalViewPrivate {}

#[glib::object_subclass]
impl ObjectSubclass for HistoricalViewPrivate {
    const NAME: &'static str = "HistoricalView";
    type Type = HistoricalView;
    type ParentType = gtk::Box;

    fn new() -> Self {
        Self {}
    }
}

impl ObjectImpl for HistoricalViewPrivate {}
impl WidgetImpl for HistoricalViewPrivate {}
impl BoxImpl for HistoricalViewPrivate {}

glib::wrapper! {
    pub struct HistoricalView(ObjectSubclass<HistoricalViewPrivate>) @extends gtk::Box, gtk::Widget;
}

impl HistoricalView {
    pub fn new() -> Self {
        let s: Self = Object::builder().build();

        let label = gtk::Label::builder()
            .label("Database has been configured and now it is time to show data")
            .build();
        s.append(&label);
        s
    }
}

/// These are the possible states of the main application view.
enum MainView {
    /// The application is not configured yet. This is a basic background widget to take up the
    /// space when there is no data to be shown.
    Unconfigured(UnconfiguredView),

    /// The Historical view shows a history of records and whatnot.
    Historical(HistoricalView),
}

/// The application window, or the main window, is the main user interface for the app. Almost
/// everything occurs here.
struct AppWindow {
    app: App,
    window: adw::ApplicationWindow,
    current_view: RefCell<MainView>,
}

impl AppWindow {
    /// Construct a new App Window.
    ///
    /// adw_app is an Adwaita application. Application windows need to have access to this, but
    /// otherwise we don't use this.
    ///
    /// app is a core [App] object which encapsulates all of the basic logic.
    fn new(adw_app: &adw::Application, app: App) -> AppWindow {
        let window = adw::ApplicationWindow::builder()
            .application(adw_app)
            .width_request(800)
            .height_request(600)
            .build();

        let current_view = if app.database.read().unwrap().is_none() {
            MainView::Unconfigured(UnconfiguredView::new())
        } else {
            MainView::Historical(HistoricalView::new())
        };

        let stylesheet = String::from_utf8(
            resources_lookup_data(
                &format!("{}style.css", RESOURCE_BASE_PATH),
                gio::ResourceLookupFlags::NONE,
            )
            .expect("stylesheet must be available in the resources")
            .to_vec(),
        )
        .expect("to parse stylesheet");

        let provider = gtk::CssProvider::new();
        provider.load_from_data(&stylesheet);

        let context = window.style_context();
        context.add_provider(&provider, STYLE_PROVIDER_PRIORITY_USER);

        window.present();

        let s = Self {
            app,
            window,
            current_view: RefCell::new(current_view),
        };
        s.redraw();
        s
    }

    // Switch views.
    //
    // This function only replaces the old view with the one which matches the current view state.
    // If there is any other setup/teardown to do, it will handle that as well.
    fn redraw(&self) {
        match *self.current_view.borrow() {
            MainView::Unconfigured(ref view) => self.window.set_content(Some(view)),
            MainView::Historical(ref view) => self.window.set_content(Some(view)),
        }
    }
}

fn main() {
    // I still don't fully understand gio resources. resources_register_include! is convenient
    // because I don't have to deal with filesystem locations at runtime. However, I think other
    // GTK applications do that rather than compiling the resources directly into the app. So, I'm
    // unclear as to how I want to handle this.
    gio::resources_register_include!("com.luminescent-dreams.fitnesstrax.gresource")
        .expect("to register resources");

    let app_id = if std::env::var_os("ENV") == Some("dev".into()) {
        APP_ID_DEV
    } else {
        APP_ID_PROD
    };

    let settings = gio::Settings::new(app_id);

    println!("database path: {}", settings.string("series-path"));

    let app = App::new();

    /*
    let runtime = tokio::runtime::Builder::new_multi_thread()
        .enable_all()
        .build()
        .unwrap();
        */

    let adw_app = adw::Application::builder()
        .application_id(app_id)
        .resource_base_path(RESOURCE_BASE_PATH)
        .build();

    adw_app.connect_activate(move |adw_app| {
        AppWindow::new(adw_app, app.clone());
    });

    let args: Vec<String> = env::args().collect();
    ApplicationExtManual::run_with_args(&adw_app, &args);
}