use gtk::glib::clone;
use gtk::prelude::{BoxExt, ButtonExt, GtkWindowExt};
use relm4::{ComponentParts, ComponentSender, RelmApp, RelmWidgetExt, SimpleComponent};

struct App {
    counter: u8,
}

#[derive(Debug)]
enum Msg {
    Increment,
    Decrement,
}

struct AppWidgets {
    // window: gtk::Window,
    // vbox: gtk::Box,
    // inc_button: gtk::Button,
    // dec_button: gtk::Button,
    label: gtk::Label,
}

impl SimpleComponent for App {
    type Init = u8;
    type Input = Msg;
    type Output = ();
    type Widgets = AppWidgets;
    type Root = gtk::Window;

    fn init_root() -> Self::Root {
        gtk::Window::builder()
            .title("Simple app")
            .default_width(300)
            .default_height(100)
            .build()
    }

    // Initialize the component.
    fn init(
        counter: Self::Init,
        window: Self::Root,
        sender: ComponentSender<Self>,
    ) -> ComponentParts<Self> {
        let model = App { counter };

        let vbox = gtk::Box::builder()
            .orientation(gtk::Orientation::Vertical)
            .spacing(5)
            .build();

        let inc_button = gtk::Button::with_label("Increment");
        let dec_button = gtk::Button::with_label("Decrement");

        let label = gtk::Label::new(Some(&format!("Counter: {}", model.counter)));
        label.set_margin_all(5);

        window.set_child(Some(&vbox));
        vbox.set_margin_all(5);
        vbox.append(&inc_button);
        vbox.append(&dec_button);
        vbox.append(&label);

        inc_button.connect_clicked(clone!(
            #[strong]
            sender,
            move |_| {
                sender.input(Msg::Increment);
            }
        ));

        dec_button.connect_clicked(clone!(
            #[strong]
            sender,
            move |_| {
                sender.input(Msg::Decrement);
            }
        ));

        let widgets = AppWidgets { label };

        ComponentParts { model, widgets }
    }

    fn update(&mut self, msg: Self::Input, _sender: ComponentSender<Self>) {
        match msg {
            Msg::Increment => {
                self.counter = self.counter.wrapping_add(1);
            }
            Msg::Decrement => {
                self.counter = self.counter.wrapping_sub(1);
            }
        }
    }

    // Update the view to represent the updated model.
    fn update_view(&self, widgets: &mut Self::Widgets, _sender: ComponentSender<Self>) {
        widgets
            .label
            .set_label(&format!("Counter: {}", self.counter));
    }
}

fn main() {
    let app = RelmApp::new("relm4.example.simple_manual");
    app.run::<App>(0);
}