use cosmic_panel_config::{PanelSize, PanelAnchor};
use gtk4::{glib, prelude::*, subclass::prelude::*, PositionType};
use relm4_macros::view;

use crate::deref_cell::DerefCell;

static STYLE: &str = "
button.cosmic_applet_button {
    border-radius: 12px;
    transition: 100ms;
    padding: 4px;
    border-color: transparent;
    background: transparent;
    outline-color: transparent;
}
";

#[derive(Default)]
pub struct AppletButtonInner {
    menu_button: DerefCell<gtk4::MenuButton>,
    popover: DerefCell<gtk4::Popover>,
}

#[glib::object_subclass]
impl ObjectSubclass for AppletButtonInner {
    const NAME: &'static str = "CosmicAppletButton";
    type Type = AppletButton;
    type ParentType = gtk4::Widget;
}

impl ObjectImpl for AppletButtonInner {
    fn constructed(&self, obj: &AppletButton) {
        let position = std::env::var("COSMIC_PANEL_ANCHOR")
        .ok()
        .and_then(|anchor| anchor.parse::<PanelAnchor>().ok())
        .map(|anchor| match anchor {
            PanelAnchor::Left => PositionType::Right,
            PanelAnchor::Right => PositionType::Left,
            PanelAnchor::Top => PositionType::Bottom,
            PanelAnchor::Bottom => PositionType::Top,
        });
        view! {
            menu_button = gtk4::MenuButton {
                set_parent: obj,
                add_css_class: "cosmic_applet_button",
                set_has_frame: false,
                #[wrap(Some)]
                set_popover: popover = &gtk4::Popover {
                    set_has_arrow: false,
                }
            },
            provider = gtk4::CssProvider {
                load_from_data: STYLE.as_bytes(),
            }
        }
        if let Some(position) = position {
            popover.set_position(position);
        }
        obj.set_layout_manager(Some(&gtk4::BinLayout::new()));
        obj.style_context()
            .add_provider(&provider, gtk4::STYLE_PROVIDER_PRIORITY_APPLICATION);

        self.menu_button.set(menu_button);
        self.popover.set(popover);
    }

    fn dispose(&self, _obj: &AppletButton) {
        self.menu_button.unparent();
    }
}

impl WidgetImpl for AppletButtonInner {
    fn compute_expand(&self, _obj: &AppletButton, hexpand: &mut bool, vexpand: &mut bool) {
        *hexpand = self
            .menu_button
            .compute_expand(gtk4::Orientation::Horizontal);
        *vexpand = self.menu_button.compute_expand(gtk4::Orientation::Vertical);
    }

    fn request_mode(&self, _obj: &AppletButton) -> gtk4::SizeRequestMode {
        self.menu_button.request_mode()
    }
}

impl WindowImpl for AppletButtonInner {}

glib::wrapper! {
    pub struct AppletButton(ObjectSubclass<AppletButtonInner>)
        @extends gtk4::Widget;
}

impl Default for AppletButton {
    fn default() -> Self {
        Self::new()
    }
}

impl AppletButton {
    pub fn new() -> Self {
        glib::Object::new(&[]).unwrap()
    }

    fn inner(&self) -> &AppletButtonInner {
        AppletButtonInner::from_instance(self)
    }

    pub fn set_button_child(&self, child: Option<&impl IsA<gtk4::Widget>>) {
        self.inner().menu_button.set_child(child);
    }

    pub fn set_button_icon_name(&self, name: &str) {
        let image = gtk4::Image::from_icon_name(name);
        let pixels = std::env::var("COSMIC_PANEL_SIZE")
            .ok()
            .and_then(|size| match size.parse::<PanelSize>() {
                Ok(PanelSize::XL) => Some(64),
                Ok(PanelSize::L) => Some(48),
                Ok(PanelSize::M) => Some(36),
                Ok(PanelSize::S) => Some(24),
                Ok(PanelSize::XS) => Some(18),
                Err(_) => Some(36),
            })
            .unwrap_or(36);
        image.set_pixel_size(pixels);
        self.set_button_child(Some(&image));
    }

    pub fn set_button_label(&self, label: &str) {
        self.inner().menu_button.set_label(label);
    }

    pub fn set_popover_child(&self, child: Option<&impl IsA<gtk4::Widget>>) {
        self.inner().popover.set_child(child);
    }

    pub fn popdown(&self) {
        self.inner().popover.popdown();
    }

    pub fn popup(&self) {
        self.inner().popover.popup();
    }

    // XXX better API? Actual signal
    pub fn connect_activate<F: Fn(&Self) + 'static>(&self, f: F) -> glib::SignalHandlerId {
        self.inner()
            .menu_button
            .connect_activate(glib::clone!(@weak self as _self => move |_| {
                f(&_self)
            }))
    }
}