// Copyright 2023 System76 <info@system76.com>
// SPDX-License-Identifier: GPL-3.0-only

use cosmic::app::{Core, Settings, Task};
use cosmic::cctk::wayland_protocols::xdg::shell::client::xdg_positioner::Gravity;
use cosmic::iced::{Point, Rectangle, Size};
use cosmic::iced_runtime::platform_specific::wayland::subsurface::SctkSubsurfaceSettings;
use cosmic::surface;
use cosmic::{
    Element, executor,
    iced::{
        self, Background, Border, Length, Subscription, alignment,
        event::wayland::{OutputEvent, SessionLockEvent},
        futures::{self, SinkExt},
        platform_specific::shell::wayland::commands::session_lock::{
            destroy_lock_surface, get_lock_surface, lock, unlock,
        },
    },
    iced_runtime::core::window::Id as SurfaceId,
    theme, widget,
};
use cosmic_config::CosmicConfigEntry;
use cosmic_greeter_daemon::{TimeAppletConfig, UserData};
use std::time::Duration;
use std::{
    any::TypeId,
    env,
    ffi::{CStr, CString},
    fs,
    os::fd::OwnedFd,
    path::PathBuf,
    process,
    sync::Arc,
};
use tokio::{sync::mpsc, task};
use wayland_client::{Proxy, protocol::wl_output::WlOutput};

use crate::{
    common::{self, Common},
    fl,
};

fn lockfile_opt() -> Option<PathBuf> {
    let runtime_dir = dirs::runtime_dir()?;
    let session_id = env::var("XDG_SESSION_ID").ok()?;
    Some(runtime_dir.join(format!("cosmic-greeter-{}.lock", session_id)))
}

pub fn main(user: pwd::Passwd) -> Result<(), Box<dyn std::error::Error>> {
    env_logger::Builder::from_env(env_logger::Env::default().default_filter_or("warn")).init();

    crate::localize::localize();

    let mut user_data = UserData::from(user);
    // We are already the user at this point
    user_data.load_config_as_user();

    let flags = Flags {
        user_data,
        lockfile_opt: lockfile_opt(),
    };

    let settings = Settings::default().no_main_window(true);

    cosmic::app::run::<App>(settings, flags)?;

    Ok(())
}

pub fn pam_thread(username: String, conversation: Conversation) -> Result<(), pam_client::Error> {
    //TODO: send errors to GUI, restart process

    // Create PAM context
    let mut context = pam_client::Context::new("cosmic-greeter", Some(&username), conversation)?;

    // Authenticate the user (ask for password, 2nd-factor token, fingerprint, etc.)
    log::info!("authenticate");
    context.authenticate(pam_client::Flag::NONE)?;

    // Validate the account (is not locked, expired, etc.)
    log::info!("acct_mgmt");
    context.acct_mgmt(pam_client::Flag::NONE)?;

    Ok(())
}

pub struct Conversation {
    msg_tx: futures::channel::mpsc::Sender<cosmic::Action<Message>>,
    value_rx: mpsc::Receiver<String>,
}

impl Conversation {
    fn prompt_value(
        &mut self,
        prompt_c: &CStr,
        secret: bool,
    ) -> Result<CString, pam_client::ErrorCode> {
        let prompt = prompt_c.to_str().map_err(|err| {
            log::error!("failed to convert prompt to UTF-8: {:?}", err);
            pam_client::ErrorCode::CONV_ERR
        })?;

        futures::executor::block_on(async {
            self.msg_tx
                .send(cosmic::Action::App(
                    common::Message::Prompt(prompt.to_string(), secret, Some(String::new())).into(),
                ))
                .await
        })
        .map_err(|err| {
            log::error!("failed to send prompt: {:?}", err);
            pam_client::ErrorCode::CONV_ERR
        })?;

        let value = self.value_rx.blocking_recv().ok_or_else(|| {
            log::error!("failed to receive value: channel closed");
            pam_client::ErrorCode::CONV_ERR
        })?;

        CString::new(value).map_err(|err| {
            log::error!("failed to convert value to C string: {:?}", err);
            pam_client::ErrorCode::CONV_ERR
        })
    }

    fn message(&mut self, prompt_c: &CStr) -> Result<(), pam_client::ErrorCode> {
        let prompt = prompt_c.to_str().map_err(|err| {
            log::error!("failed to convert prompt to UTF-8: {:?}", err);
            pam_client::ErrorCode::CONV_ERR
        })?;

        futures::executor::block_on(async {
            self.msg_tx
                .send(cosmic::Action::App(
                    common::Message::Prompt(prompt.to_string(), false, None).into(),
                ))
                .await
        })
        .map_err(|err| {
            log::error!("failed to send prompt: {:?}", err);
            pam_client::ErrorCode::CONV_ERR
        })
    }
}

impl pam_client::ConversationHandler for Conversation {
    fn prompt_echo_on(&mut self, prompt_c: &CStr) -> Result<CString, pam_client::ErrorCode> {
        log::info!("prompt_echo_on {:?}", prompt_c);
        self.prompt_value(prompt_c, false)
    }
    fn prompt_echo_off(&mut self, prompt_c: &CStr) -> Result<CString, pam_client::ErrorCode> {
        log::info!("prompt_echo_off {:?}", prompt_c);
        self.prompt_value(prompt_c, true)
    }
    fn text_info(&mut self, prompt_c: &CStr) {
        log::info!("text_info {:?}", prompt_c);
        match self.message(prompt_c) {
            Ok(()) => (),
            Err(err) => {
                log::warn!("failed to send text_info: {:?}", err);
            }
        }
    }
    fn error_msg(&mut self, prompt_c: &CStr) {
        //TODO: treat error type differently?
        log::info!("error_msg {:?}", prompt_c);
        match self.message(prompt_c) {
            Ok(()) => (),
            Err(err) => {
                log::warn!("failed to send error_msg: {:?}", err);
            }
        }
    }
}

#[derive(Clone)]
pub struct Flags {
    user_data: UserData,
    lockfile_opt: Option<PathBuf>,
}

///TODO: this is custom code that should be better handled by libcosmic
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum Dropdown {
    Keyboard,
}

/// Messages that are used specifically by our [`App`].
#[derive(Clone, Debug)]
pub enum Message {
    None,
    Common(common::Message),
    OutputEvent(OutputEvent, WlOutput),
    SessionLockEvent(SessionLockEvent),
    Channel(mpsc::Sender<String>),
    BackgroundState(cosmic_bg_config::state::State),
    DropdownToggle(Dropdown),
    KeyboardLayout(usize),
    Inhibit(Arc<OwnedFd>),
    Submit(String),
    Surface(surface::Action),
    Suspend,
    TimeAppletConfig(TimeAppletConfig),
    Error(String),
    Lock,
    Unlock,
}

impl From<common::Message> for Message {
    fn from(message: common::Message) -> Self {
        Self::Common(message)
    }
}

#[derive(Clone, Debug)]
enum State {
    Locking,
    Locked {
        task_handle: cosmic::iced::task::Handle,
    },
    Unlocking,
    Unlocked,
}

impl Drop for State {
    fn drop(&mut self) {
        // Abort the locked task when the state is changed.
        if let Self::Locked { task_handle } = self {
            log::info!("dropping lockscreen tasks");
            task_handle.abort();
        }
    }
}

/// The [`App`] stores application-specific state.
pub struct App {
    common: Common<Message>,
    flags: Flags,
    state: State,
    dropdown_opt: Option<Dropdown>,
    inhibit_opt: Option<Arc<OwnedFd>>,
    value_tx_opt: Option<mpsc::Sender<String>>,
}

impl App {
    fn menu(&self, surface_id: SurfaceId) -> Element<Message> {
        let window_width = self
            .common
            .window_size
            .get(&surface_id)
            .map(|s| s.width)
            .unwrap_or(800.);
        let menu_width = if window_width > 800. {
            800.
        } else {
            window_width
        };
        let left_element = {
            let military_time = self.flags.user_data.time_applet_config.military_time;
            let date_time_column = self.common.time.date_time_widget(military_time);

            let mut status_row = widget::row::with_capacity(2).padding(16.0).spacing(12.0);

            if let Some(network_icon) = self.common.network_icon_opt {
                status_row = status_row.push(widget::icon::from_name(network_icon));
            }

            if let Some((power_icon, power_percent)) = &self.common.power_info_opt {
                status_row = status_row.push(iced::widget::row![
                    widget::icon::from_name(power_icon.clone()),
                    widget::text(format!("{:.0}%", power_percent)),
                ]);
            }

            //TODO: move code for custom dropdowns to libcosmic
            let menu_checklist = |label, value, message| {
                Element::from(
                    widget::menu::menu_button(vec![
                        if value {
                            widget::icon::from_name("object-select-symbolic")
                                .size(16)
                                .icon()
                                .width(Length::Fixed(16.0))
                                .into()
                        } else {
                            widget::Space::with_width(Length::Fixed(17.0)).into()
                        },
                        widget::Space::with_width(Length::Fixed(8.0)).into(),
                        widget::text(label)
                            .align_x(iced::alignment::Horizontal::Left)
                            .into(),
                    ])
                    .on_press(message),
                )
            };
            let dropdown_menu = |items| {
                widget::container(widget::column::with_children(items))
                    .padding(1)
                    //TODO: move style to libcosmic
                    .class(theme::Container::custom(|theme| {
                        let cosmic = theme.cosmic();
                        let component = &cosmic.background.component;
                        widget::container::Style {
                            icon_color: Some(component.on.into()),
                            text_color: Some(component.on.into()),
                            background: Some(Background::Color(component.base.into())),
                            border: Border {
                                radius: 8.0.into(),
                                width: 1.0,
                                color: component.divider.into(),
                            },
                            ..Default::default()
                        }
                    }))
                    .width(Length::Fixed(240.0))
            };

            let mut input_button = widget::popover(
                widget::button::custom(widget::icon::from_name("input-keyboard-symbolic"))
                    .padding(12.0)
                    .on_press(Message::DropdownToggle(Dropdown::Keyboard)),
            )
            .position(widget::popover::Position::Bottom);
            if matches!(self.dropdown_opt, Some(Dropdown::Keyboard)) {
                let mut items = Vec::with_capacity(self.common.active_layouts.len());
                for (i, layout) in self.common.active_layouts.iter().enumerate() {
                    items.push(menu_checklist(
                        &layout.description,
                        i == 0,
                        Message::KeyboardLayout(i),
                    ));
                }
                input_button = input_button.popup(dropdown_menu(items));
            }

            //TODO: implement these buttons
            let button_row = iced::widget::row![
                /*TODO: greeter accessibility options
                widget::button::custom(widget::icon::from_name(
                    "applications-accessibility-symbolic"
                ))
                .padding(12.0)
                .on_press(Message::None),
                */
                widget::tooltip(
                    input_button,
                    widget::text(fl!("keyboard-layout")),
                    widget::tooltip::Position::Top
                ),
                widget::tooltip(
                    widget::button::custom(widget::icon::from_name("system-suspend-symbolic"))
                        .padding(12.0)
                        .on_press(Message::Suspend),
                    widget::text(fl!("suspend")),
                    widget::tooltip::Position::Top
                ),
            ]
            .padding([16.0, 0.0, 0.0, 0.0])
            .spacing(8.0);

            widget::container(iced::widget::column![
                date_time_column,
                widget::divider::horizontal::default().width(Length::Fixed(menu_width / 2. - 16.)),
                status_row,
                widget::divider::horizontal::default().width(Length::Fixed(menu_width / 2. - 16.)),
                button_row,
            ])
            .align_x(alignment::Horizontal::Left)
        };

        let right_element = {
            let mut column = widget::column::with_capacity(2)
                .spacing(12.0)
                .max_width(280.0);

            match &self.flags.user_data.icon_opt {
                Some(icon) => {
                    column = column.push(
                        widget::container(
                            //TODO: cache image handle?
                            widget::Image::new(widget::image::Handle::from_bytes(icon.clone()))
                                .width(Length::Fixed(78.0))
                                .height(Length::Fixed(78.0)),
                        )
                        .width(Length::Fill)
                        .align_x(alignment::Horizontal::Center),
                    )
                }
                None => {}
            }

            column = column.push(
                widget::container(widget::text::title4(&self.flags.user_data.full_name))
                    .width(Length::Fill)
                    .align_x(alignment::Horizontal::Center),
            );

            match &self.common.prompt_opt {
                Some((prompt, secret, value_opt)) => match value_opt {
                    Some(value) => {
                        let text_input_id = self
                            .common
                            .surface_names
                            .get(&surface_id)
                            .and_then(|id| self.common.text_input_ids.get(id))
                            .cloned()
                            .unwrap_or_else(|| cosmic::widget::Id::new("text_input"));

                        let mut text_input = widget::secure_input(
                            prompt.clone(),
                            value.as_str(),
                            Some(
                                common::Message::Prompt(
                                    prompt.clone(),
                                    !*secret,
                                    Some(value.clone()),
                                )
                                .into(),
                            ),
                            *secret,
                        )
                        .id(text_input_id)
                        .on_input(|input| {
                            common::Message::Prompt(prompt.clone(), *secret, Some(input)).into()
                        })
                        .on_submit(Message::Submit);

                        if *secret {
                            text_input = text_input.password()
                        }

                        column = column.push(text_input);

                        if self.common.caps_lock {
                            column = column.push(widget::text(fl!("caps-lock")));
                        }
                    }
                    None => {
                        column = column.push(widget::text(prompt));
                    }
                },
                None => {}
            }

            if let Some(error) = &self.common.error_opt {
                column = column.push(widget::text(error));
            }

            widget::container(column)
                .align_x(alignment::Horizontal::Center)
                .width(Length::Fill)
        };

        widget::container(
            widget::layer_container(
                iced::widget::row![left_element, right_element]
                    .align_y(alignment::Alignment::Center),
            )
            .layer(cosmic::cosmic_theme::Layer::Background)
            .padding(16)
            .class(cosmic::theme::Container::Custom(Box::new(
                |theme: &cosmic::Theme| {
                    // Use background appearance as the base
                    let mut appearance = widget::container::Catalog::style(
                        theme,
                        &cosmic::theme::Container::Background,
                    );
                    appearance.border = iced::Border::default().rounded(16.0);
                    appearance
                },
            )))
            .width(Length::Fill)
            .height(Length::Shrink),
        )
        .padding([32.0, 0.0, 0.0, 0.0])
        .width(Length::Fill)
        .height(Length::Fill)
        .align_x(alignment::Horizontal::Center)
        .align_y(alignment::Vertical::Top)
        .class(cosmic::theme::Container::Transparent)
        .into()
    }
}

/// Implement [`cosmic::Application`] to integrate with COSMIC.
impl cosmic::Application for App {
    /// Default async executor to use with the app.
    type Executor = executor::Default;

    /// Argument received [`cosmic::Application::new`].
    type Flags = Flags;

    /// Message type specific to our [`App`].
    type Message = Message;

    /// The unique application ID to supply to the window manager.
    const APP_ID: &'static str = "com.system76.CosmicGreeter";

    fn core(&self) -> &Core {
        &self.common.core
    }

    fn core_mut(&mut self) -> &mut Core {
        &mut self.common.core
    }

    /// Creates the application, and optionally emits command on initialize.
    fn init(core: Core, flags: Self::Flags) -> (Self, Task<Self::Message>) {
        let (mut common, common_task) = Common::init(core);
        common.on_output_event = Some(Box::new(|output_event, output| {
            Message::OutputEvent(output_event, output)
        }));
        common.on_session_lock_event = Some(Box::new(|evt| Message::SessionLockEvent(evt)));
        common.update_user_data(&flags.user_data);

        let already_locked = match flags.lockfile_opt {
            Some(ref lockfile) => lockfile.exists(),
            None => false,
        };

        let mut app = App {
            common,
            flags,
            state: State::Unlocked,
            dropdown_opt: None,
            inhibit_opt: None,
            value_tx_opt: None,
        };

        let task = if cfg!(feature = "logind") {
            if already_locked {
                // Recover previously locked state
                log::info!("recovering previous locked state");
                app.state = State::Locking;
                lock()
            } else {
                // When logind feature is used, wait for lock signal
                Task::none()
            }
        } else {
            // When logind feature not used, lock immediately
            log::info!("locking immediately");
            app.state = State::Locking;
            lock()
        };

        (app, Task::batch([task, common_task]))
    }

    /// Handle application events here.
    fn update(&mut self, message: Self::Message) -> Task<Self::Message> {
        match message {
            Message::None => {}
            Message::Common(common_message) => {
                return self.common.update(common_message);
            }
            Message::OutputEvent(output_event, output) => {
                match output_event {
                    OutputEvent::Created(output_info_opt) => {
                        log::info!("output {}: created", output.id());

                        let surface_id = SurfaceId::unique();
                        let subsurface_id = SurfaceId::unique();

                        if let Some(old_surface_id) =
                            self.common.surface_ids.insert(output.clone(), surface_id)
                        {
                            //TODO: remove old surface?
                            log::warn!(
                                "output {}: already had surface ID {:?}",
                                output.id(),
                                old_surface_id
                            );
                            return Task::none();
                        }

                        let size = if let Some((w, h)) =
                            output_info_opt.as_ref().and_then(|info| info.logical_size)
                        {
                            Some((Some(w as u32), Some(h as u32)))
                        } else {
                            Some((None, None))
                        };
                        match output_info_opt {
                            Some(output_info) => match output_info.name {
                                Some(output_name) => {
                                    self.common
                                        .output_names
                                        .insert(output.clone(), output_name.clone());
                                    self.common
                                        .surface_names
                                        .insert(surface_id, output_name.clone());
                                    self.common
                                        .surface_names
                                        .insert(subsurface_id, output_name.clone());
                                    self.common.surface_images.remove(&surface_id);
                                    self.common.update_wallpapers(&self.flags.user_data);
                                    let text_input_id =
                                        widget::Id::new(format!("input-{output_name}",));
                                    self.common
                                        .text_input_ids
                                        .insert(output_name.clone(), text_input_id.clone());
                                }
                                None => {
                                    log::warn!("output {}: no output name", output.id());
                                }
                            },
                            None => {
                                log::warn!("output {}: no output info", output.id());
                            }
                        }

                        let unwrapped_size = size
                            .map(|s| (s.0.unwrap_or(1920), s.1.unwrap_or(1080)))
                            .unwrap_or((1920, 1080));
                        let (loc, sub_size) = if unwrapped_size.0 > 800 {
                            (
                                Point::new(unwrapped_size.0 as f32 / 2. - 400., 32.),
                                Size::new(800., unwrapped_size.1 as f32 - 32.),
                            )
                        } else {
                            (
                                Point::new(0., 32.),
                                Size::new(unwrapped_size.0 as f32, unwrapped_size.1 as f32 - 32.),
                            )
                        };
                        self.common.window_size.insert(
                            surface_id,
                            Size::new(unwrapped_size.0 as f32, unwrapped_size.1 as f32),
                        );

                        self.common
                            .subsurface_rects
                            .insert(output.clone(), Rectangle::new(loc, sub_size));

                        let msg = cosmic::surface::action::subsurface(
                            move |_: &mut App| SctkSubsurfaceSettings {
                                parent: surface_id,
                                id: subsurface_id,
                                loc,
                                size: Some(sub_size),
                                z: 10,
                                steal_keyboard_focus: true,
                                gravity: Gravity::BottomRight,
                                offset: (0, 0),
                                input_zone: None,
                            },
                            Some(Box::new(move |app: &App| {
                                app.menu(subsurface_id).map(cosmic::Action::App)
                            })),
                        );

                        if matches!(self.state, State::Locked { .. }) {
                            return Task::batch([
                                get_lock_surface(surface_id, output),
                                cosmic::task::message(cosmic::Action::Cosmic(
                                    cosmic::app::Action::Surface(msg),
                                )),
                            ]);
                        }
                    }
                    OutputEvent::Removed => {
                        log::info!("output {}: removed", output.id());
                        match self.common.surface_ids.remove(&output) {
                            Some(surface_id) => {
                                self.common.surface_images.remove(&surface_id);
                                self.common.surface_names.remove(&surface_id);
                                self.common.window_size.remove(&surface_id);
                                if let Some(n) = self.common.surface_names.remove(&surface_id) {
                                    self.common.text_input_ids.remove(&n);
                                }
                                if matches!(self.state, State::Locked { .. }) {
                                    return destroy_lock_surface(surface_id);
                                }
                            }
                            None => {
                                log::warn!("output {}: no surface found", output.id());
                            }
                        }
                    }
                    OutputEvent::InfoUpdate(info) => {
                        let size = if let Some((w, h)) = info.logical_size {
                            Some((Some(w as u32), Some(h as u32)))
                        } else {
                            Some((None, None))
                        };
                        let unwrapped_size = size
                            .map(|s| (s.0.unwrap_or(1920), s.1.unwrap_or(1080)))
                            .unwrap_or((1920, 1080));
                        let (loc, sub_size) = if unwrapped_size.0 > 800 {
                            (
                                Point::new(unwrapped_size.0 as f32 / 2. - 400., 32.),
                                Size::new(800., unwrapped_size.1 as f32 - 32.),
                            )
                        } else {
                            (Point::ORIGIN, Size::new(1920., 1080.))
                        };
                        self.common
                            .subsurface_rects
                            .insert(output.clone(), Rectangle::new(loc, sub_size));

                        log::info!("output {}: info update", output.id());
                    }
                }
            }
            Message::SessionLockEvent(session_lock_event) => match session_lock_event {
                SessionLockEvent::Focused(..) => {}
                SessionLockEvent::Locked => {
                    log::info!("session locked");
                    if matches!(self.state, State::Locked { .. }) {
                        return Task::none();
                    }

                    let username = self.flags.user_data.name.clone();
                    let (locked_task, locked_handle) = cosmic::task::stream(
                        cosmic::iced_futures::stream::channel(16, |mut msg_tx| async move {
                            // Send heartbeat once a second to update time.
                            let heartbeat_future = {
                                let mut output = msg_tx.clone();
                                async move {
                                    let mut interval =
                                        tokio::time::interval(Duration::from_secs(1));

                                    loop {
                                        output
                                            .send(cosmic::Action::App(Message::None))
                                            .await
                                            .unwrap();

                                        interval.tick().await;
                                    }
                                }
                            };

                            let pam_future = async {
                                loop {
                                    let (value_tx, value_rx) = mpsc::channel(16);
                                    msg_tx
                                        .send(cosmic::Action::App(Message::Channel(value_tx)))
                                        .await
                                        .unwrap();

                                    let pam_res = {
                                        let username = username.clone();
                                        let msg_tx = msg_tx.clone();
                                        task::spawn_blocking(move || {
                                            pam_thread(username, Conversation { msg_tx, value_rx })
                                        })
                                        .await
                                        .unwrap()
                                    };

                                    match pam_res {
                                        Ok(()) => {
                                            log::info!("successfully authenticated");
                                            msg_tx
                                                .send(cosmic::Action::App(Message::Unlock))
                                                .await
                                                .unwrap();
                                            break;
                                        }
                                        Err(err) => {
                                            log::warn!("authentication error: {}", err);
                                            msg_tx
                                                .send(cosmic::Action::App(Message::Error(
                                                    err.to_string(),
                                                )))
                                                .await
                                                .unwrap();
                                        }
                                    }
                                }
                            };

                            futures::pin_mut!(heartbeat_future);
                            futures::pin_mut!(pam_future);
                            futures::future::select(heartbeat_future, pam_future).await;
                        }),
                    )
                    .abortable();

                    let mut commands = Vec::with_capacity(self.common.surface_ids.len() + 1);
                    commands.push(locked_task);

                    self.state = State::Locked {
                        task_handle: locked_handle,
                    };

                    // Allow suspend
                    self.inhibit_opt = None;
                    // Create lock surfaces

                    for (output, surface_id) in self.common.surface_ids.iter() {
                        commands.push(get_lock_surface(*surface_id, output.clone()));

                        if let Some((rect, name)) = self
                            .common
                            .subsurface_rects
                            .get(output)
                            .copied()
                            .zip(self.common.output_names.get(output))
                        {
                            let subsurface_id = SurfaceId::unique();
                            let surface_id = *surface_id;
                            self.common.surface_names.insert(surface_id, name.clone());
                            self.common
                                .surface_names
                                .insert(subsurface_id, name.clone());
                            let msg = cosmic::surface::action::subsurface(
                                move |_: &mut App| SctkSubsurfaceSettings {
                                    parent: surface_id,
                                    id: subsurface_id,
                                    loc: Point::new(rect.x, rect.y),
                                    size: Some(Size::new(rect.width, rect.height)),
                                    z: 10,
                                    steal_keyboard_focus: true,
                                    gravity: Gravity::BottomRight,
                                    offset: (0, 0),
                                    input_zone: None,
                                },
                                Some(Box::new(move |app: &App| {
                                    app.menu(subsurface_id).map(cosmic::Action::App)
                                })),
                            );
                            commands.push(cosmic::task::message(cosmic::Action::Cosmic(
                                cosmic::app::Action::Surface(msg),
                            )));
                        } else {
                            log::error!("no rectangle for subsurface...");
                        }
                    }
                    return Task::batch(commands);
                }
                SessionLockEvent::Unlocked => {
                    log::info!("session unlocked");
                    self.state = State::Unlocked;

                    let mut commands = Vec::new();
                    for (_output, surface_id) in self.common.surface_ids.iter() {
                        self.common.surface_names.remove(surface_id);
                        self.common.window_size.remove(surface_id);
                        commands.push(destroy_lock_surface(*surface_id));
                    }
                    if cfg!(feature = "logind") {
                        return Task::batch(commands);
                        // When using logind feature, stick around for more lock signals
                    } else {
                        // When not using logind feature, exit immediately after unlocking
                        //TODO: cleaner method to exit?
                        process::exit(0);
                    }
                }
                //TODO: handle finished signal
                _ => {}
            },
            Message::Channel(value_tx) => {
                self.value_tx_opt = Some(value_tx);
            }
            Message::BackgroundState(bg_state) => {
                self.flags.user_data.bg_state = bg_state;
                self.flags.user_data.load_wallpapers_as_user();
                self.common.surface_images.clear();
                self.common.update_wallpapers(&self.flags.user_data);
            }
            Message::DropdownToggle(dropdown) => {
                if self.dropdown_opt == Some(dropdown) {
                    self.dropdown_opt = None;
                } else {
                    self.dropdown_opt = Some(dropdown);
                }
            }
            Message::Inhibit(inhibit) => {
                self.inhibit_opt = Some(inhibit);
            }
            Message::KeyboardLayout(layout_i) => {
                if layout_i < self.common.active_layouts.len() {
                    self.common.active_layouts.swap(0, layout_i);
                    self.common.set_xkb_config(&self.flags.user_data);
                }
                if self.dropdown_opt == Some(Dropdown::Keyboard) {
                    self.dropdown_opt = None
                }
            }
            Message::Submit(value) => {
                self.common.prompt_opt = None;
                self.common.error_opt = None;
                match self.value_tx_opt.take() {
                    Some(value_tx) => {
                        // Clear errors
                        self.common.error_opt = None;
                        return cosmic::task::future(async move {
                            value_tx.send(value).await.unwrap();
                            Message::Channel(value_tx)
                        });
                    }
                    None => log::warn!("tried to submit when value_tx_opt not set"),
                }
            }
            Message::Suspend => {
                #[cfg(feature = "logind")]
                return cosmic::Task::future(async move { crate::logind::suspend().await.err() })
                    .and_then(|err| {
                        log::error!("failed to suspend: {:?}", err);
                        cosmic::task::message(cosmic::Action::App(Message::Error(err.to_string())))
                    });
            }
            Message::TimeAppletConfig(config) => {
                self.flags.user_data.time_applet_config = config;
            }
            Message::Error(error) => {
                self.common.error_opt = Some(error);
            }
            Message::Lock => match self.state {
                State::Unlocked => {
                    log::info!("session locking");
                    self.state = State::Locking;
                    // Clear errors
                    self.common.error_opt = None;
                    // Clear value_tx
                    self.value_tx_opt = None;
                    // Try to create lockfile when locking
                    if let Some(ref lockfile) = self.flags.lockfile_opt {
                        if let Err(err) = fs::File::create(lockfile) {
                            log::warn!("failed to create lockfile {:?}: {}", lockfile, err);
                        }
                    }
                    // Tell compositor to lock
                    return lock();
                }
                State::Unlocking => {
                    log::info!("session still unlocking");
                }
                State::Locking | State::Locked { .. } => {
                    log::info!("session already locking or locked");
                }
            },
            Message::Unlock => {
                match self.state {
                    State::Locked { .. } => {
                        log::info!("sessing unlocking");
                        self.state = State::Unlocking;
                        // Clear errors
                        self.common.error_opt = None;
                        // Clear value_tx
                        self.value_tx_opt = None;
                        // Try to delete lockfile when unlocking
                        if let Some(ref lockfile) = self.flags.lockfile_opt {
                            if let Err(err) = fs::remove_file(lockfile) {
                                log::warn!("failed to remove lockfile {:?}: {}", lockfile, err);
                            }
                        }

                        // Destroy lock surfaces
                        let mut commands = Vec::with_capacity(self.common.surface_ids.len() + 1);

                        for (_output, surface_id) in self.common.surface_ids.iter() {
                            self.common.surface_names.remove(surface_id);
                            self.common.window_size.remove(&surface_id);
                            commands.push(destroy_lock_surface(*surface_id));
                        }

                        // Tell compositor to unlock
                        commands.push(unlock());

                        // Wait to exit until `Unlocked` event, when server has processed unlock
                        return Task::batch(commands);
                    }
                    State::Locking => {
                        log::info!("session still locking");
                    }
                    State::Unlocking | State::Unlocked => {
                        log::info!("session already unlocking or unlocked");
                    }
                }
            }
            Message::Surface(a) => {
                return cosmic::task::message(cosmic::Action::Cosmic(
                    cosmic::app::Action::Surface(a),
                ));
            }
        }
        Task::none()
    }

    // Not used for layer surface window
    fn view(&self) -> Element<Self::Message> {
        unimplemented!()
    }

    /// Creates a view after each update.
    fn view_window(&self, surface_id: SurfaceId) -> Element<Self::Message> {
        let img = self
            .common
            .surface_images
            .get(&surface_id)
            .unwrap_or(&self.common.fallback_background);
        widget::image(img)
            .content_fit(iced::ContentFit::Cover)
            .width(Length::Fill)
            .height(Length::Fill)
            .into()
    }

    fn subscription(&self) -> Subscription<Self::Message> {
        let mut subscriptions = Vec::with_capacity(7);

        subscriptions.push(self.common.subscription().map(Message::from));

        struct BackgroundSubscription;
        subscriptions.push(
            cosmic_config::config_state_subscription(
                TypeId::of::<BackgroundSubscription>(),
                cosmic_bg_config::NAME.into(),
                cosmic_bg_config::state::State::version(),
            )
            .map(|res| {
                if !res.errors.is_empty() {
                    log::info!("errors loading background state: {:?}", res.errors);
                }
                Message::BackgroundState(res.config)
            }),
        );

        struct TimeAppletSubscription;
        subscriptions.push(
            cosmic_config::config_subscription(
                TypeId::of::<TimeAppletSubscription>(),
                "com.system76.CosmicAppletTime".into(),
                TimeAppletConfig::VERSION,
            )
            .map(|res| {
                if !res.errors.is_empty() {
                    log::info!("errors loading background state: {:?}", res.errors);
                }
                Message::TimeAppletConfig(res.config)
            }),
        );

        #[cfg(feature = "logind")]
        {
            subscriptions.push(crate::logind::subscription());
        }

        Subscription::batch(subscriptions)
    }
}