paneru 0.3.1

use accessibility_sys::{AXIsProcessTrustedWithOptions, kAXTrustedCheckOptionPrompt};
use bevy::ecs::entity::Entity;
use bevy::ecs::query::Has;
use bevy::ecs::resource::Resource;
use bevy::ecs::system::Query;
use core::ptr::NonNull;
use log::{debug, error, trace, warn};
use notify::{RecursiveMode, Watcher};
use objc2_core_foundation::{
    CFArray, CFDictionary, CFEqual, CFMutableData, CFNumber, CFNumberType, CFRetained, CFString,
    CGPoint, CGRect, kCFBooleanTrue,
};
use objc2_core_graphics::{
    CGDirectDisplayID, CGDisplayBounds, CGError, CGGetActiveDisplayList, CGRectContainsPoint,
    CGWarpMouseCursorPosition,
};
use std::ops::{Deref, DerefMut};
use std::path::Path;
use std::ptr::null_mut;
use std::slice::from_raw_parts_mut;
use std::time::Duration;
use stdext::function_name;

use crate::ecs::Unmanaged;
use crate::errors::{Error, Result};
use crate::events::{Event, EventSender};
use crate::manager::skylight::SLSGetSpaceManagementMode;
use crate::platform::{ConnID, ProcessSerialNumber, WinID};
use crate::util::{AXUIWrapper, create_array, get_array_values, get_cfdict_value, symlink_target};
use app::ApplicationOS;
pub use app::{Application, ApplicationApi};
pub use display::{Display, Panel, WindowPane};
pub use process::{Process, ProcessApi};
pub use skylight::AXUIElementCopyAttributeValue;
use skylight::{
    _AXUIElementCreateWithRemoteToken, SLSCopyActiveMenuBarDisplayIdentifier,
    SLSCopyAssociatedWindows, SLSCopyBestManagedDisplayForRect, SLSCopyManagedDisplayForWindow,
    SLSCopyManagedDisplaySpaces, SLSCopyWindowsWithOptionsAndTags, SLSFindWindowAndOwner,
    SLSGetConnectionIDForPSN, SLSGetCurrentCursorLocation, SLSGetDisplayMenubarHeight,
    SLSGetWindowBounds, SLSMainConnectionID, SLSManagedDisplayGetCurrentSpace,
    SLSWindowIteratorAdvance, SLSWindowIteratorGetAttributes, SLSWindowIteratorGetParentID,
    SLSWindowIteratorGetTags, SLSWindowIteratorGetWindowID, SLSWindowQueryResultCopyWindows,
    SLSWindowQueryWindows,
};
pub use windows::{Window, WindowApi, WindowOS, WindowPadding, ax_window_id};

mod app;
mod display;
mod process;
mod skylight;
mod windows;

/// Defines the interface for a window manager, abstracting OS-specific operations.
pub trait WindowManagerApi: Send + Sync {
    /// Creates a new `Application` instance from a given `ProcessApi`.
    ///
    /// # Arguments
    ///
    /// * `process` - A reference to the `ProcessApi` trait object representing the application's process.
    ///
    /// # Returns
    ///
    /// `Ok(Application)` if the application is successfully created, otherwise `Err(Error)`.
    fn new_application(&self, process: &dyn ProcessApi) -> Result<Application>;
    /// Refreshes the state of a given display, including its spaces and windows.
    ///
    /// # Arguments
    ///
    /// * `display` - A mutable reference to the `Display` to refresh.
    /// * `windows` - A mutable query for all `Window` components, their `Entity`, and `Has<Unmanaged>` status.
    fn refresh_display(
        &self,
        display: &mut Display,
        windows: &mut Query<(&mut Window, Entity, Has<Unmanaged>)>,
    );
    /// Retrieves a list of window IDs associated with a parent window.
    ///
    /// # Arguments
    ///
    /// * `window_id` - The `WinID` of the parent window.
    ///
    /// # Returns
    ///
    /// A `Vec<WinID>` containing the IDs of associated child windows.
    fn get_associated_windows(&self, window_id: WinID) -> Vec<WinID>;
    /// Retrieves a list of all currently present displays.
    ///
    /// # Returns
    ///
    /// A `Vec<Display>` containing `Display` objects for all present displays.
    fn present_displays(&self) -> Vec<Display>;
    /// Retrieves the `CGDirectDisplayID` of the active menu bar display.
    ///
    /// # Returns
    ///
    /// `Ok(u32)` with the display ID if successful, otherwise `Err(Error)`.
    fn active_display_id(&self) -> Result<u32>;
    /// Retrieves the ID of the current active space on a given display.
    ///
    /// # Arguments
    ///
    /// * `display_id` - The `CGDirectDisplayID` of the display.
    ///
    /// # Returns
    ///
    /// `Ok(u64)` with the space ID if successful, otherwise `Err(Error)`.
    fn active_display_space(&self, display_id: CGDirectDisplayID) -> Result<u64>;
    /// Centers the mouse cursor on a given window within its display bounds if it's not already within the window.
    ///
    /// # Arguments
    ///
    /// * `window` - A reference to the `Window` to center the mouse on.
    /// * `display_bounds` - The `CGRect` representing the bounds of the display the window is on.
    fn center_mouse(&self, window: &Window, display_bounds: &CGRect);
    /// Adds existing windows for a given application, potentially resolving unresolved windows.
    ///
    /// # Arguments
    ///
    /// * `app` - A mutable reference to the `Application` whose windows are to be added.
    /// * `spaces` - A slice of space IDs to query for windows.
    /// * `refresh_index` - An integer indicating the refresh index (used internally for tracking).
    ///
    /// # Returns
    ///
    /// `Ok(Vec<Window>)` containing the found and added windows, otherwise `Err(Error)`.
    fn add_existing_application_windows(
        &self,
        app: &mut Application,
        spaces: &[u64],
        refresh_index: i32,
    ) -> Result<Vec<Window>>;
    /// Finds the `WinID` of a window at a given screen point.
    ///
    /// # Arguments
    ///
    /// * `point` - A reference to the `CGPoint` representing the screen coordinate.
    ///
    /// # Returns
    ///
    /// `Ok(WinID)` with the found window's ID if successful, otherwise `Err(Error)`.
    fn find_window_at_point(&self, point: &CGPoint) -> Result<WinID>;
    /// Returns a list of `WinID`s for all windows in a given workspace (space).
    ///
    /// # Arguments
    ///
    /// * `space_id` - The ID of the space to query.
    ///
    /// # Returns
    ///
    /// `Ok(Vec<WinID>)` containing the list of window IDs, otherwise `Err(Error)`.
    fn windows_in_workspace(&self, space_id: u64) -> Result<Vec<WinID>>;
    /// Sends an `Event::Exit` to the event loop, signaling the application to quit.
    ///
    /// # Returns
    ///
    /// `Ok(())` if the exit event is sent successfully, otherwise `Err(Error)`.
    fn quit(&self) -> Result<()>;

    fn setup_config_watcher(&self, path: &Path) -> Result<Box<dyn Watcher>>;
}

/// `WindowManager` is a Bevy resource that holds a boxed `WindowManagerApi` trait object.
/// It allows for dynamic dispatch to the OS-specific window management implementation.
#[derive(Resource)]
pub struct WindowManager(pub Box<dyn WindowManagerApi>);

impl Deref for WindowManager {
    type Target = Box<dyn WindowManagerApi>;
    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

impl DerefMut for WindowManager {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.0
    }
}

/// `WindowManagerOS` is the macOS-specific implementation of the `WindowManagerApi` trait.
/// It directly interacts with the macOS `SkyLight` and Accessibility APIs to manage windows.
pub struct WindowManagerOS {
    main_cid: ConnID,
    event_sender: EventSender,
}

impl WindowManagerOS {
    /// Creates a new `WindowManagerOS` instance.
    /// It initializes the main connection ID to the macOS `SkyLight` API.
    ///
    /// # Arguments
    ///
    /// * `event_sender` - The `EventSender` to dispatch events from the window manager.
    ///
    /// # Returns
    ///
    /// A new `WindowManagerOS` instance.
    pub fn new(event_sender: EventSender) -> Self {
        let main_cid = unsafe { SLSMainConnectionID() };
        debug!("{}: My connection id: {main_cid}", function_name!());

        Self {
            main_cid,
            event_sender,
        }
    }

    /// Retrieves a list of space IDs for a given display UUID.
    /// It queries the `SkyLight` API for managed display spaces and filters by the provided UUID.
    ///
    /// # Arguments
    ///
    /// * `uuid` - A reference to the `CFString` representing the display's UUID.
    ///
    /// # Returns
    ///
    /// `Ok(Vec<u64>)` with the list of space IDs if successful, otherwise `Err(Error)` if the spaces cannot be retrieved or the display is not found.
    fn display_space_list(&self, uuid: &CFString) -> Result<Vec<u64>> {
        let display_spaces = NonNull::new(unsafe { SLSCopyManagedDisplaySpaces(self.main_cid) })
            .map(|ptr| unsafe { CFRetained::from_raw(ptr) })
            .ok_or(Error::PermissionDenied(format!(
                "{}: can not copy managed display spaces for {}.",
                function_name!(),
                self.main_cid
            )))?;

        for display in get_array_values(display_spaces.as_ref()) {
            let display_ref = unsafe { display.as_ref() };
            trace!("{}: display {display_ref:?}", function_name!());
            let identifier = get_cfdict_value::<CFString>(
                display_ref,
                &CFString::from_static_str("Display Identifier"),
            )?;
            let identifier_ref = unsafe { identifier.as_ref() };
            debug!(
                "{}: identifier {identifier_ref:?} uuid {uuid:?}",
                function_name!()
            );
            // FIXME: For some reason the main display does not have a UUID in the name, but is
            // referenced as simply "Main".
            if identifier_ref.to_string().ne("Main") && !CFEqual(Some(identifier_ref), Some(uuid)) {
                continue;
            }

            let spaces =
                get_cfdict_value::<CFArray>(display_ref, &CFString::from_static_str("Spaces"))?;
            debug!("{}: spaces {spaces:?}", function_name!());

            let space_list = get_array_values(unsafe { spaces.as_ref() })
                .filter_map(|space| {
                    let num = get_cfdict_value::<CFNumber>(
                        unsafe { space.as_ref() },
                        &CFString::from_static_str("id64"),
                    )
                    .ok()?;

                    let mut id = 0u64;
                    unsafe {
                        CFNumber::value(
                            num.as_ref(),
                            CFNumber::r#type(num.as_ref()),
                            NonNull::from(&mut id).as_ptr().cast(),
                        )
                    };
                    (id != 0).then_some(id)
                })
                .collect::<Vec<u64>>();
            return Ok(space_list);
        }
        Err(Error::PermissionDenied(format!(
            "{}: could not get any displays for {}",
            function_name!(),
            self.main_cid
        )))
    }

    /// Retrieves the UUID of the active menu bar display.
    /// This typically corresponds to the display where the primary menu bar is located.
    ///
    /// # Returns
    ///
    /// `Ok(CFRetained<CFString>)` with the UUID if successful, otherwise `Err(Error)` if the active display cannot be determined.
    fn active_display_uuid(&self) -> Result<CFRetained<CFString>> {
        unsafe {
            let ptr = SLSCopyActiveMenuBarDisplayIdentifier(self.main_cid);
            let ptr = NonNull::new(ptr.cast_mut()).ok_or(Error::NotFound(format!(
                "{}: can not find active display for connection {}.",
                function_name!(),
                self.main_cid
            )))?;
            Ok(CFRetained::from_raw(ptr))
        }
    }

    /// Retrieves the UUID of the display a specific window is currently on.
    /// It first tries `SLSCopyManagedDisplayForWindow` and then falls back to `SLSCopyBestManagedDisplayForRect`
    /// using the window's bounds if the first call fails.
    ///
    /// # Arguments
    ///
    /// * `window_id` - The `WinID` of the window.
    ///
    /// # Returns
    ///
    /// `Ok(CFRetained<CFString>)` with the display UUID if successful, otherwise `Err(Error)` if the display cannot be determined.
    fn display_uuid(&self, window_id: WinID) -> Result<CFRetained<CFString>> {
        let uuid = unsafe {
            NonNull::new(SLSCopyManagedDisplayForWindow(self.main_cid, window_id).cast_mut())
                .map(|uuid| CFRetained::from_raw(uuid))
        };
        uuid.or_else(|| {
            let mut frame = CGRect::default();
            unsafe {
                SLSGetWindowBounds(self.main_cid, window_id, &mut frame);
                NonNull::new(SLSCopyBestManagedDisplayForRect(self.main_cid, frame).cast_mut())
                    .map(|uuid| CFRetained::from_raw(uuid))
            }
        })
        .ok_or(Error::InvalidInput(format!(
            "{}: can not get display uuid for window {window_id}.",
            function_name!()
        )))
    }

    /// Retrieves the `CGDirectDisplayID` of the display a specific window is currently on.
    /// It internally calls `display_uuid` and then converts the UUID to a display ID.
    ///
    /// # Arguments
    ///
    /// * `window_id` - The `WinID` of the window.
    ///
    /// # Returns
    ///
    /// `Ok(u32)` with the display ID if successful, otherwise `Err(Error)`.
    fn display_id(&self, window_id: WinID) -> Result<CGDirectDisplayID> {
        let uuid = self.display_uuid(window_id);
        uuid.and_then(|uuid| Display::id_from_uuid(&uuid))
    }

    /// Repopulates the current window panel with eligible windows from a specified space.
    /// This function filters windows based on eligibility and ensures they are present in the panel.
    ///
    /// # Arguments
    ///
    /// * `space_id` - The ID of the space to refresh windows from.
    /// * `windows` - A query for all `Window` components and their `Entity`.
    ///
    /// # Returns
    ///
    /// A `Vec<Entity>` containing the entities of eligible windows in the specified space.
    fn refresh_windows_space(
        &self,
        space_id: u64,
        windows: &Query<(&Window, Entity)>,
    ) -> Vec<Entity> {
        space_window_list_for_connection(self.main_cid, &[space_id], None, false)
            .inspect_err(|err| {
                warn!(
                    "{}: getting windows for space {space_id}: {err}",
                    function_name!()
                );
            })
            .unwrap_or_default()
            .into_iter()
            .filter_map(|window_id| windows.iter().find(|(window, _)| window.id() == window_id))
            .filter_map(|(window, entity)| window.is_eligible().then_some(entity))
            .collect()
    }

    /// Returns the connection ID (`ConnID`) for a given process serial number (`PSN`).
    ///
    /// # Arguments
    ///
    /// * `psn` - The `ProcessSerialNumber` of the process.
    ///
    /// # Returns
    ///
    /// `Some(ConnID)` if the connection ID is found, otherwise `None`.
    fn connection_for_process(&self, psn: ProcessSerialNumber) -> Option<ConnID> {
        let mut connection: ConnID = 0;
        unsafe { SLSGetConnectionIDForPSN(self.main_cid, &psn, &mut connection) };
        (connection != 0).then_some(connection)
    }
}

impl WindowManagerApi for WindowManagerOS {
    fn new_application(&self, process: &dyn ProcessApi) -> Result<Application> {
        let connection = self.connection_for_process(process.psn());
        ApplicationOS::new(connection, process, &self.event_sender)
            .map(|app| Application::new(Box::new(app)))
    }

    /// Refreshes the state of a given display, including its spaces and windows.
    /// It repopulates each `WindowPane` with eligible windows from its corresponding space,
    /// ensuring that existing windows maintain their order and unmanaged windows are ignored.
    ///
    /// # Arguments
    ///
    /// * `display` - A mutable reference to the `Display` to refresh.
    /// * `windows` - A mutable query for all `Window` components, their `Entity`, and `Has<Unmanaged>` status.
    fn refresh_display(
        &self,
        display: &mut Display,
        windows: &mut Query<(&mut Window, Entity, Has<Unmanaged>)>,
    ) {
        debug!(
            "{}: Refreshing windows on display {}",
            function_name!(),
            display.id()
        );

        let display_bounds = display.bounds;
        for (space_id, pane) in &mut display.spaces {
            let mut lens = windows.transmute_lens::<(&Window, Entity)>();
            let new_windows = self.refresh_windows_space(*space_id, &lens.query());

            // Preserve the order - do not flush existing windows.
            for window_entity in pane.all_windows() {
                if !new_windows.contains(&window_entity) {
                    pane.remove(window_entity);
                }
            }
            for window_entity in new_windows {
                if windows
                    .get(window_entity)
                    .is_ok_and(|(_, _, unmanaged)| unmanaged)
                {
                    // Window is not managed, do not insert it into the panel.
                    continue;
                }
                if pane.index_of(window_entity).is_err() {
                    pane.append(window_entity);
                    if let Ok((mut window, _, _)) = windows.get_mut(window_entity) {
                        _ = window.update_frame(Some(&display_bounds));
                    }
                }
            }
            debug!(
                "{}: space {space_id}: after refresh {pane}",
                function_name!()
            );
        }
    }

    /// Returns child windows of the main window.
    fn get_associated_windows(&self, window_id: WinID) -> Vec<WinID> {
        let window_list = unsafe {
            let arr_ref = SLSCopyAssociatedWindows(self.main_cid, window_id);
            CFRetained::retain(arr_ref)
        };

        get_array_values(&window_list)
            .filter_map(|item| {
                let mut child_wid: WinID = 0;
                if unsafe {
                    CFNumber::value(
                        item.as_ref(),
                        CFNumberType::SInt32Type,
                        NonNull::from(&mut child_wid).as_ptr().cast(),
                    )
                } {
                    debug!(
                        "{}: checking {}'s childen: {}",
                        function_name!(),
                        window_id,
                        child_wid
                    );
                    (child_wid != 0).then_some(child_wid)
                } else {
                    warn!(
                        "{}: Unable to find subwindows of window {}: {item:?}.",
                        function_name!(),
                        window_id
                    );
                    None
                }
            })
            .collect()
    }

    /// Retrieves a list of all currently present displays, along with their associated spaces.
    ///
    /// # Returns
    ///
    /// A `Vec<Self>` containing `Display` objects for all present displays.
    fn present_displays(&self) -> Vec<Display> {
        let mut count = 0u32;
        unsafe {
            CGGetActiveDisplayList(0, null_mut(), &raw mut count);
        }
        if count < 1 {
            return vec![];
        }
        let mut displays = Vec::with_capacity(count.try_into().unwrap());
        unsafe {
            CGGetActiveDisplayList(count, displays.as_mut_ptr(), &raw mut count);
            displays.set_len(count.try_into().unwrap());
        }
        displays
            .into_iter()
            .flat_map(|id| {
                let uuid = Display::uuid_from_id(id);
                uuid.and_then(|uuid| {
                    self.display_space_list(uuid.as_ref()).map(|spaces| {
                        let bounds = CGDisplayBounds(id);
                        let mut menubar_height: u32 = 0;
                        unsafe { SLSGetDisplayMenubarHeight(id, &raw mut menubar_height) };
                        debug!("{}: menubar height: {menubar_height}", function_name!());
                        Display::new(id, spaces, bounds, menubar_height)
                    })
                })
            })
            .collect()
    }

    /// Retrieves the `CGDirectDisplayID` of the active menu bar display.
    ///
    /// # Returns
    ///
    /// `Ok(u32)` with the display ID if successful, otherwise `Err(Error)`.
    fn active_display_id(&self) -> Result<u32> {
        let uuid = self.active_display_uuid()?;
        Display::id_from_uuid(&uuid)
    }

    /// Retrieves the ID of the current active space on this display.
    ///
    /// # Returns
    ///
    /// `Ok(u64)` with the space ID if successful, otherwise `Err(Error)`.
    fn active_display_space(&self, display_id: CGDirectDisplayID) -> Result<u64> {
        // let cid = self.main_cid;
        // let uuid = Display::active_display_uuid(cid);
        // uuid.map(|uuid| unsafe { SLSManagedDisplayGetCurrentSpace(cid, uuid.deref()) })
        Display::uuid_from_id(display_id).map(|uuid| unsafe {
            SLSManagedDisplayGetCurrentSpace(self.main_cid, &raw const *uuid)
        })
    }

    /// Centers the mouse cursor on the window if it's not already within the window's bounds.
    fn center_mouse(&self, window: &Window, display_bounds: &CGRect) {
        let mut cursor = CGPoint::default();
        if unsafe { CGError::Success != SLSGetCurrentCursorLocation(self.main_cid, &mut cursor) } {
            warn!(
                "{}: Unable to get current cursor position.",
                function_name!()
            );
            return;
        }
        let frame = window.frame();
        if CGRectContainsPoint(frame, cursor) {
            return;
        }

        let center = CGPoint::new(
            display_bounds.origin.x + frame.origin.x + frame.size.width / 2.0,
            display_bounds.origin.y + frame.origin.y + frame.size.height / 2.0,
        );
        let display_id = self.display_id(window.id());
        #[allow(clippy::redundant_closure)]
        let bounds = display_id.map(|display_id| CGDisplayBounds(display_id));
        if bounds.is_ok_and(|bounds| !CGRectContainsPoint(bounds, center)) {
            return;
        }
        CGWarpMouseCursorPosition(center);
    }

    /// Adds existing windows for a given application, attempting to resolve any that are not yet found.
    /// It compares the application's reported window list with the global window list and uses brute-forcing if necessary.
    ///
    /// # Arguments
    ///
    /// * `app` - A mutable reference to the `Application` whose windows are to be added.
    /// * `spaces` - A slice of space IDs to query.
    /// * `refresh_index` - An integer indicating the refresh index, used to determine if all windows are resolved.
    ///
    /// # Returns
    ///
    /// `Ok(Vec<Window>)` containing the found windows, otherwise `Err(Error)`.
    // bool window_manager_add_existing_application_windows(struct space_manager *sm,
    // struct window_manager *wm, struct application *application, int refresh_index)
    fn add_existing_application_windows(
        &self,
        app: &mut Application,
        spaces: &[u64],
        refresh_index: i32,
    ) -> Result<Vec<Window>> {
        // uint32_t *global_window_list = window_manager_existing_application_window_list(application, &global_window_count);
        // if (!global_window_list) return result;
        let global_window_list = existing_application_window_list(self.main_cid, app, spaces)?;
        if global_window_list.is_empty() {
            return Err(Error::InvalidInput(format!(
                "{}: No windows found for {app}",
                function_name!()
            )));
        }
        debug!(
            "{}: {app} has global windows: {global_window_list:?}",
            function_name!()
        );

        let mut found_windows: Vec<Window> = Vec::new();
        for found in app.window_list()? {
            match found {
                Ok(found_window) => {
                    if !found_windows
                        .iter()
                        .any(|window| window.id() == found_window.id())
                    {
                        found_windows.push(found_window);
                    }
                }
                Err(err) => {
                    debug!("{}: create window: {err}", function_name!());
                }
            }
        }

        // if (global_window_count == window_count-empty_count)
        if global_window_list.len() == found_windows.len() {
            if refresh_index != -1 {
                debug!(
                    "{}: All windows for {:?} are now resolved",
                    function_name!(),
                    app.psn(),
                );
            }
        } else {
            // for (int i = 0; i < global_window_count; ++i) {
            //     struct window *window = window_manager_find_window(wm, global_window_list[i]);
            //     if (!window) {
            //         missing_window = true;
            //         break;
            //     }
            // }
            let find_window =
                |window_id| found_windows.iter().find(|window| window.id() == window_id);
            let mut app_window_list: Vec<WinID> = global_window_list
                .iter()
                .filter(|window_id| find_window(**window_id).is_none())
                .copied()
                .collect();

            // if (missing_window) {
            if !app_window_list.is_empty() {
                debug!(
                    "{}: {:?} has windows that are not yet resolved",
                    function_name!(),
                    app.psn(),
                );
                found_windows.extend(bruteforce_windows(app, &mut app_window_list));

                // } else {
                //     // debug("%s: all windows for %s are now resolved\n", __FUNCTION__, application->name);
                //     info!(
                //         "add_existing_application_windows: All windows for {} are now resolved (second pass)",
                //         app.inner().name
                //     );
                //     // buf_del(wm->applications_to_refresh, refresh_index);
                //     result = true;
            }
        }

        // if (window_list_ref) CFRelease(window_list_ref);
        Ok(found_windows)
    }

    /// Finds a window at a given screen point using `SkyLight` API.
    ///
    /// # Arguments
    ///
    /// * `point` - A reference to the `CGPoint` representing the screen coordinate.
    ///
    /// # Returns
    ///
    /// `Ok(WinID)` with the found window's ID if successful, otherwise `Err(Error)`.
    fn find_window_at_point(&self, point: &CGPoint) -> Result<WinID> {
        let mut window_id: WinID = 0;
        let mut window_conn_id: ConnID = 0;
        let mut window_point = CGPoint { x: 0f64, y: 0f64 };
        unsafe {
            SLSFindWindowAndOwner(
                self.main_cid,
                0, // filter window id
                1,
                0,
                point,
                &mut window_point,
                &mut window_id,
                &mut window_conn_id,
            )
        };
        if self.main_cid == window_conn_id {
            unsafe {
                SLSFindWindowAndOwner(
                    self.main_cid,
                    window_id,
                    -1,
                    0,
                    point,
                    &mut window_point,
                    &mut window_id,
                    &mut window_conn_id,
                )
            };
        }
        if window_id == 0 {
            Err(Error::invalid_window(&format!(
                "{}: could not find a window at {point:?}",
                function_name!()
            )))
        } else {
            Ok(window_id)
        }
    }

    /// Returns a list of windows in a given workspace.
    fn windows_in_workspace(&self, space_id: u64) -> Result<Vec<WinID>> {
        space_window_list_for_connection(self.main_cid, &[space_id], None, true)
    }

    fn quit(&self) -> Result<()> {
        self.event_sender.send(Event::Exit)
    }

    fn setup_config_watcher(&self, path: &Path) -> Result<Box<dyn Watcher>> {
        let setup = notify::Config::default()
            .with_poll_interval(Duration::from_secs(3))
            .with_follow_symlinks(false);
        let config_handler = ConfigHandler(self.event_sender.clone());
        let symlink = symlink_target(path);

        let mut watcher = if let Some(symlink) = symlink {
            setup.with_follow_symlinks(true);
            let mut watcher = notify::PollWatcher::new(config_handler, setup)?;
            debug!(
                "{}: watching symlink target {} for changes.",
                function_name!(),
                symlink.display()
            );
            watcher.watch(&symlink, RecursiveMode::NonRecursive)?;

            Ok::<Box<dyn Watcher>, Error>(Box::new(watcher))
        } else {
            Ok::<Box<dyn Watcher>, Error>(Box::new(notify::RecommendedWatcher::new(
                config_handler,
                setup,
            )?))
        }?;
        debug!(
            "{}: watching config file {} for changes.",
            function_name!(),
            path.display()
        );
        watcher.watch(path, RecursiveMode::NonRecursive)?;
        Ok(watcher)
    }
}

/// Retrieves a list of window IDs for specified spaces and connection, with an option to include minimized windows.
/// This function uses `SkyLight` API calls to query windows based on their space, connection, and visibility tags.
///
/// # Arguments
///
/// * `main_cid` - The main connection ID.
/// * `spaces` - A slice of space IDs to query windows from.
/// * `cid` - An optional connection ID. If `None`, the main connection ID is used.
/// * `also_minimized` - A boolean indicating whether to include minimized windows in the result.
///
/// # Returns
///
/// `Ok(Vec<WinID>)` containing the list of window IDs if successful, otherwise `Err(Error)`.
fn space_window_list_for_connection(
    main_cid: ConnID,
    spaces: &[u64],
    cid: Option<ConnID>,
    also_minimized: bool,
) -> Result<Vec<WinID>> {
    let space_list_ref = create_array(spaces, CFNumberType::SInt64Type)?;

    let mut set_tags = 0i64;
    let mut clear_tags = 0i64;
    let options = if also_minimized { 0x7 } else { 0x2 };
    let ptr = NonNull::new(unsafe {
        SLSCopyWindowsWithOptionsAndTags(
            main_cid,
            cid.unwrap_or(0),
            &raw const *space_list_ref,
            options,
            &mut set_tags,
            &mut clear_tags,
        )
    })
    .ok_or(Error::InvalidInput(format!(
        "{}: nullptr returned from SLSCopyWindowsWithOptionsAndTags.",
        function_name!()
    )))?;
    let window_list_ref = unsafe { CFRetained::from_raw(ptr) };

    let count = window_list_ref.count();
    if count == 0 {
        return Err(Error::NotFound(format!(
            "{}: zero windows returned",
            function_name!()
        )));
    }

    let query = unsafe {
        CFRetained::from_raw(SLSWindowQueryWindows(
            main_cid,
            &raw const *window_list_ref,
            count,
        ))
    };
    let iterator =
        unsafe { CFRetained::from_raw(SLSWindowQueryResultCopyWindows(query.deref().into())) };

    let mut window_list = Vec::with_capacity(count.try_into()?);
    while unsafe { SLSWindowIteratorAdvance(&raw const *iterator) } {
        let tags = unsafe { SLSWindowIteratorGetTags(&raw const *iterator) };
        let attributes = unsafe { SLSWindowIteratorGetAttributes(&raw const *iterator) };
        let parent_wid: WinID = unsafe { SLSWindowIteratorGetParentID(&raw const *iterator) };
        let window_id: WinID = unsafe { SLSWindowIteratorGetWindowID(&raw const *iterator) };

        trace!(
            "{}: id: {window_id} parent: {parent_wid} tags: 0x{tags:x} attributes: 0x{attributes:x}",
            function_name!()
        );
        if found_valid_window(parent_wid, attributes, tags) {
            window_list.push(window_id);
        }
    }
    Ok(window_list)
}

/// Determines if a window is valid based on its parent ID, attributes, and tags.
/// This function implements complex logic to filter out irrelevant or invalid windows.
///
/// # Arguments
///
/// * `parent_wid` - The parent window ID.
/// * `attributes` - The attributes of the window.
/// * `tags` - The tags associated with the window.
///
/// # Returns
///
/// `true` if the window is considered valid, `false` otherwise.
fn found_valid_window(parent_wid: WinID, attributes: i64, tags: i64) -> bool {
    parent_wid == 0
        && ((0 != (attributes & 0x2) || 0 != (tags & 0x0400_0000_0000_0000))
            && (0 != (tags & 0x1) || (0 != (tags & 0x2) && 0 != (tags & 0x8000_0000))))
        || ((attributes == 0x0 || attributes == 0x1)
            && (0 != (tags & 0x1000_0000_0000_0000) || 0 != (tags & 0x0300_0000_0000_0000))
            && (0 != (tags & 0x1) || (0 != (tags & 0x2) && 0 != (tags & 0x8000_0000))))
}

/// Retrieves a list of existing application window IDs for a given application.
/// It queries windows across all active displays and spaces associated with the application's connection.
///
/// # Arguments
///
/// * `cid` - The main connection ID.
/// * `app` - A reference to the `Application` for which to retrieve window IDs.
/// * `spaces` - A slice of space IDs to query.
///
/// # Returns
///
/// `Ok(Vec<WinID>)` containing the list of window IDs if successful, otherwise `Err(Error)`.
fn existing_application_window_list(
    cid: ConnID,
    app: &Application,
    spaces: &[u64],
) -> Result<Vec<WinID>> {
    if spaces.is_empty() {
        return Err(Error::NotFound(format!(
            "{}: no spaces returned",
            function_name!()
        )));
    }
    space_window_list_for_connection(cid, spaces, app.connection(), true)
}

/// Attempts to find and add unresolved windows for a given application by brute-forcing `element_id` values.
/// This is a workaround for macOS API limitations that do not return `AXUIElementRef` for windows on inactive spaces.
///
/// # Arguments
///
/// * `app` - A reference to the `Application` whose windows are to be brute-forced.
/// * `window_list` - A mutable vector of `WinID`s representing the expected global window list; found windows are removed from this list.
fn bruteforce_windows(app: &mut Application, window_list: &mut Vec<WinID>) -> Vec<Window> {
    const MAGIC: u32 = 0x636f_636f;
    let mut found_windows = Vec::new();
    debug!(
        "{}: {app} has unresolved window on other desktops, bruteforcing them.",
        function_name!()
    );

    //
    // NOTE: MacOS API does not return AXUIElementRef of windows on inactive spaces. However,
    // we can just brute-force the element_id and create the AXUIElementRef ourselves.
    //  https://github.com/decodism
    //  https://github.com/lwouis/alt-tab-macos/issues/1324#issuecomment-2631035482
    //

    unsafe {
        const BUFSIZE: isize = 0x14;
        let Some(data_ref) = CFMutableData::new(None, BUFSIZE) else {
            error!("{}: error creating mutable data", function_name!());
            return found_windows;
        };
        CFMutableData::increase_length(data_ref.deref().into(), BUFSIZE);

        let data = from_raw_parts_mut(
            CFMutableData::mutable_byte_ptr(data_ref.deref().into()),
            BUFSIZE as usize,
        );
        let bytes = app.pid().to_ne_bytes();
        data[0x0..bytes.len()].copy_from_slice(&bytes);
        let bytes = MAGIC.to_ne_bytes();
        data[0x8..0x8 + bytes.len()].copy_from_slice(&bytes);

        for element_id in 0..0x7fffu64 {
            //
            // NOTE: Only the element_id changes between iterations.
            //

            let bytes = element_id.to_ne_bytes();
            data[0xc..0xc + bytes.len()].copy_from_slice(&bytes);

            let Ok(element_ref) =
                AXUIWrapper::retain(_AXUIElementCreateWithRemoteToken(data_ref.as_ref()))
            else {
                continue;
            };
            let Ok(window_id) = ax_window_id(element_ref.as_ptr()) else {
                continue;
            };

            if let Some(index) = window_list.iter().position(|&id| id == window_id) {
                window_list.remove(index);
                debug!("{}: Found window {window_id:?}", function_name!());
                if let Ok(window) = WindowOS::new(&element_ref)
                    .inspect_err(|err| warn!("{}: {err}", function_name!()))
                {
                    found_windows.push(Window::new(Box::new(window)));
                }
            }
        }
    }
    found_windows
}

/// Checks if the application has Accessibility privileges.
/// It will prompt the user to grant permission if not already granted.
///
/// # Returns
///
/// `true` if Accessibility privileges are granted, `false` otherwise.
pub fn check_ax_privilege() -> bool {
    unsafe {
        let keys = [kAXTrustedCheckOptionPrompt
            .cast::<CFString>()
            .as_ref()
            .unwrap()];
        let values = [kCFBooleanTrue.unwrap()];
        let opts = CFDictionary::from_slices(&keys, &values);
        AXIsProcessTrustedWithOptions((&raw const *opts).cast())
    }
}

/// Checks if the macOS "Displays have separate Spaces" option is enabled.
/// This is crucial for the window manager's functionality, as Paneru relies on independent spaces per display.
///
/// # Returns
///
/// `true` if separate spaces are enabled, `false` otherwise.
pub fn check_separate_spaces() -> bool {
    unsafe {
        let cid = SLSMainConnectionID();
        SLSGetSpaceManagementMode(cid) == 1
    }
}

/// `ConfigHandler` is an implementation of `notify::EventHandler` that reloads the application configuration
/// when the configuration file changes. It also dispatches a `ConfigRefresh` event.
struct ConfigHandler(EventSender);

impl notify::EventHandler for ConfigHandler {
    /// Handles file system events for the configuration file. When the content changes, it reloads the configuration.
    /// Specifically, it responds to `ModifyKind::Data(DataChange::Content)` events.
    ///
    /// # Arguments
    ///
    /// * `event` - The result of a file system event.
    fn handle_event(&mut self, event: notify::Result<notify::Event>) {
        if let Ok(event) = event {
            _ = self.0.send(Event::ConfigRefresh(event)).inspect_err(|err| {
                warn!("{}: error sending config refresh: {err}", function_name!());
            });
        }
    }
}