// Copyright (c) 2020-2023 Christopher Davis
// Copyright (c) 2022-2023 Sophie Herold
// Copyright (c) 2022-2023 Sabri Ünal
// Copyright (c) 2023 Huan Nguyen
//
// This program 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.
//
// This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
//
// SPDX-License-Identifier: GPL-3.0-or-later

use crate::about;
use crate::deps::*;
use crate::util::spawn;

use adw::prelude::*;
use adw::subclass::prelude::*;
use glib::clone;

use crate::config;
use crate::window::LpWindow;

mod imp {
    use super::*;

    // The basic struct that holds our
    // state and widgets
    #[derive(Default, Debug)]
    pub struct LpApplication {}

    // Sets up the basics for the GObject
    // The `#[glib::object_subclass] macro implements
    // some boilerplate code for the object setup, e.g. get_type()
    #[glib::object_subclass]
    impl ObjectSubclass for LpApplication {
        const NAME: &'static str = "LpApplication";
        type Type = super::LpApplication;
        type ParentType = adw::Application;
    }

    // Overrides GObject vfuncs
    impl ObjectImpl for LpApplication {
        fn constructed(&self) {
            let obj = self.obj();

            self.parent_constructed();

            // Force dark theme
            obj.style_manager()
                .set_color_scheme(adw::ColorScheme::PreferDark);

            // Set up the actions
            obj.setup_actions();
        }
    }

    // Overrides GApplication vfuncs
    impl ApplicationImpl for LpApplication {
        fn activate(&self) {
            let application = self.obj();
            let window = LpWindow::new(&*application);
            window.present();
        }

        // Handles opening files from the command line or other applications
        fn open(&self, files: &[gio::File], _hint: &str) {
            let application = self.obj();
            let win = LpWindow::new(&*application);
            win.image_view().set_images_from_files(files.to_vec());
        }
    }

    // This is empty, but we still need to provide an
    // empty implementation for each type we subclass.
    impl GtkApplicationImpl for LpApplication {}
    impl AdwApplicationImpl for LpApplication {}
}

// Creates a wrapper struct that inherits the functions
// from objects listed as @extends or interfaces it @implements.
// This is what allows us to do e.g. application.quit() on
// LpApplication without casting.
glib::wrapper! {
    pub struct LpApplication(ObjectSubclass<imp::LpApplication>)
        @extends gio::Application, gtk::Application, adw::Application,
        @implements gio::ActionGroup, gio::ActionMap;
}

// This is where the member functions of LpApplication go.
#[allow(clippy::new_without_default)]
impl LpApplication {
    pub fn new() -> Self {
        glib::Object::builder()
            .property("application-id", config::APP_ID)
            .property("flags", gio::ApplicationFlags::HANDLES_OPEN)
            .property("resource-base-path", "/org/gnome/Loupe")
            .build()
    }

    pub fn setup_actions(&self) {
        // gio::ActionEntryBuilder allows us to build and store an action on an object
        // that implements gio::ActionMap. Here we build the application's actions and
        // add them with add_action_entries().
        let actions = [
            gio::ActionEntryBuilder::new("about")
                .activate(|app: &Self, _, _| {
                    let app = app.clone();
                    spawn(async move { app.show_about().await });
                })
                .build(),
            gio::ActionEntryBuilder::new("help")
                .activate(|app: &Self, _, _| app.show_help())
                .build(),
            gio::ActionEntryBuilder::new("quit")
                .activate(|app: &Self, _, _| app.quit())
                .build(),
            gio::ActionEntryBuilder::new("new-window")
                .activate(|app: &Self, _, _| {
                    let win = LpWindow::new(app);
                    win.present();
                })
                .build(),
        ];

        self.add_action_entries(actions);

        self.set_accels_for_action("app.help", &["F1"]);
        self.set_accels_for_action("app.quit", &["<Ctrl>Q"]);
        self.set_accels_for_action("app.new-window", &["<Ctrl>N"]);

        self.set_accels_for_action("win.open", &["<Ctrl>O"]);
        self.set_accels_for_action("win.print", &["<Ctrl>P"]);
        self.set_accels_for_action("win.copy", &["<Ctrl>C"]);
        self.set_accels_for_action("win.trash", &["Delete", "KP_Delete"]);
        self.set_accels_for_action("win.show-help-overlay", &["<Ctrl>question"]);
        self.set_accels_for_action("win.leave-fullscreen", &["Escape"]);
        self.set_accels_for_action("win.toggle-properties", &["F9", "<Alt>Return"]);
        self.set_accels_for_action("win.toggle-fullscreen", &["F11"]);
        self.set_accels_for_action("win.set-background", &["<Ctrl>F8"]);

        self.set_accels_for_action("win.image-left", &["Left", "Page_Down"]);
        self.set_accels_for_action("win.image-right", &["Right", "Page_Up"]);
        self.set_accels_for_action("win.first", &["Home"]);
        self.set_accels_for_action("win.last", &["End"]);

        self.set_accels_for_action(
            "win.zoom-to-exact(1.0)",
            &["1", "KP_1", "<Ctrl>1", "<Ctrl>KP_1"],
        );
        self.set_accels_for_action(
            "win.zoom-to-exact(2.0)",
            &["2", "KP_2", "<Ctrl>2", "<Ctrl>KP_2"],
        );
        self.set_accels_for_action("win.zoom-best-fit", &["0", "KP_0", "<Ctrl>0", "<Ctrl>KP_0"]);
        self.set_accels_for_action(
            "win.zoom-in",
            &[
                "<Ctrl>plus",
                "plus",
                "<Ctrl>equal",
                "equal",
                "<Ctrl>KP_Add",
                "KP_Add",
            ],
        );
        self.set_accels_for_action(
            "win.zoom-out",
            &["<Ctrl>minus", "minus", "<Ctrl>KP_Subtract", "KP_Subtract"],
        );

        self.set_accels_for_action("win.pan-left", &["<Ctrl>Left"]);
        self.set_accels_for_action("win.pan-right", &["<Ctrl>Right"]);
        self.set_accels_for_action("win.pan-up", &["<Ctrl>Up"]);
        self.set_accels_for_action("win.pan-down", &["<Ctrl>Down"]);

        self.set_accels_for_action("win.rotate_cw", &["<Ctrl>R"]);
        self.set_accels_for_action("win.rotate_ccw", &["<Ctrl><Shift>R"]);

        self.set_accels_for_action("window.close", &["<Ctrl>W"]);
    }

    pub async fn show_about(&self) {
        let about = about::window().await;

        if let Some(window) = self.active_window() {
            about.set_transient_for(Some(&window));
        }

        about.present();
    }

    pub fn show_help(&self) {
        spawn(clone!(@weak self as app => async move {
            let context = app
                .active_window()
                .map(|w| gtk::prelude::WidgetExt::display(&w).app_launch_context());

            if let Err(e) = gio::AppInfo::launch_default_for_uri_future("help:loupe", context.as_ref()).await {
                log::error!("Failed to launch help: {}", e.message());
            }
        }));
    }
}