use {
    crate::{
        backend::ConnectorId,
        cursor::KnownCursor,
        fixed::Fixed,
        ifs::wl_seat::{NodeSeatState, WlSeatGlobal, tablet::TabletTool},
        rect::Rect,
        renderer::Renderer,
        state::State,
        tree::{
            Direction, FindTreeResult, FindTreeUsecase, FoundNode, Node, NodeId, NodeLayerLink,
            NodeLocation, OutputNode, StackedNode, TileDragDestination, WorkspaceDragDestination,
            WorkspaceNodeId, walker::NodeVisitor,
        },
        utils::{copyhashmap::CopyHashMap, linkedlist::LinkedList},
    },
    std::{
        cell::{Cell, RefCell},
        mem,
        ops::Deref,
        rc::{Rc, Weak},
    },
};

pub struct DisplayNode {
    pub id: NodeId,
    pub extents: Cell<Rect>,
    visible: Cell<bool>,
    suspend_restore_kb_foci: RefCell<Vec<(Rc<WlSeatGlobal>, Weak<dyn Node>)>>,
    pub outputs: CopyHashMap<ConnectorId, Rc<OutputNode>>,
    pub stacked: Rc<LinkedList<Rc<dyn StackedNode>>>,
    pub stacked_above_layers: Rc<LinkedList<Rc<dyn StackedNode>>>,
    pub seat_state: NodeSeatState,
}

impl DisplayNode {
    pub fn new(id: NodeId) -> Self {
        let slf = Self {
            id,
            extents: Default::default(),
            visible: Default::default(),
            suspend_restore_kb_foci: Default::default(),
            outputs: Default::default(),
            stacked: Default::default(),
            stacked_above_layers: Default::default(),
            seat_state: Default::default(),
        };
        slf.seat_state.disable_focus_history();
        slf
    }

    pub fn clear(&self) {
        self.outputs.clear();
        self.seat_state.clear();
    }

    pub fn update_extents(&self) {
        let outputs = self.outputs.lock();
        let mut x1 = i32::MAX;
        let mut y1 = i32::MAX;
        let mut x2 = i32::MIN;
        let mut y2 = i32::MIN;
        for output in outputs.values() {
            let pos = output.global.pos.get();
            x1 = x1.min(pos.x1());
            y1 = y1.min(pos.y1());
            x2 = x2.max(pos.x2());
            y2 = y2.max(pos.y2());
        }
        if x1 >= x2 {
            x1 = 0;
            x2 = 0;
        }
        if y1 >= y2 {
            y1 = 0;
            y2 = 0;
        }
        self.extents.set(Rect::new_saturating(x1, y1, x2, y2));
    }

    pub fn update_visible(&self, state: &State) {
        let visible = state.root_visible();
        let was_visible = self.visible.replace(visible);
        if !visible && was_visible {
            let mut foci = self.suspend_restore_kb_foci.borrow_mut();
            foci.clear();
            for seat in state.globals.seats.lock().values() {
                let node = seat.get_keyboard_node();
                if node.node_id() != self.id {
                    foci.push((seat.clone(), Rc::downgrade(&node)));
                }
            }
        }
        for output in self.outputs.lock().values() {
            output.update_visible();
        }
        for stacked in self.stacked.iter() {
            if !stacked.stacked_has_workspace_link() {
                stacked.stacked_set_visible(visible);
            }
        }
        for seat in state.globals.seats.lock().values() {
            seat.set_visible(visible);
        }
        if visible && !was_visible {
            for (seat, node) in mem::take(&mut *self.suspend_restore_kb_foci.borrow_mut()) {
                if seat.get_keyboard_node().node_id() == self.id {
                    if let Some(node) = node.upgrade()
                        && node.node_visible()
                    {
                        seat.focus_node(node);
                    } else {
                        seat.get_fallback_output()
                            .take_keyboard_navigation_focus(&seat, Direction::Unspecified);
                    }
                }
            }
        }
        if visible {
            state.damage(self.extents.get());
        }
    }

    pub fn tile_drag_destination(
        &self,
        source: NodeId,
        x: i32,
        y: i32,
    ) -> Option<TileDragDestination> {
        for output in self.outputs.lock().values() {
            let pos = output.node_absolute_position();
            if pos.contains(x, y) {
                return output.tile_drag_destination(source, x, y);
            }
        }
        None
    }

    pub fn workspace_drag_destination(
        &self,
        source: WorkspaceNodeId,
        x: i32,
        y: i32,
    ) -> Option<WorkspaceDragDestination> {
        for output in self.outputs.lock().values() {
            let pos = output.node_absolute_position();
            if pos.contains(x, y) {
                return output.workspace_drag_destination(source, x, y);
            }
        }
        None
    }
}

impl Node for DisplayNode {
    fn node_id(&self) -> NodeId {
        self.id
    }

    fn node_seat_state(&self) -> &NodeSeatState {
        &self.seat_state
    }

    fn node_visit(self: Rc<Self>, visitor: &mut dyn NodeVisitor) {
        visitor.visit_display(&self);
    }

    fn node_visit_children(&self, visitor: &mut dyn NodeVisitor) {
        let outputs = self.outputs.lock();
        for (_, output) in outputs.deref() {
            visitor.visit_output(output);
        }
        for stacked in self.stacked.iter() {
            stacked.deref().clone().node_visit(visitor);
        }
    }

    fn node_visible(&self) -> bool {
        true
    }

    fn node_absolute_position(&self) -> Rect {
        self.extents.get()
    }

    fn node_output(&self) -> Option<Rc<OutputNode>> {
        None
    }

    fn node_location(&self) -> Option<NodeLocation> {
        None
    }

    fn node_layer(&self) -> NodeLayerLink {
        NodeLayerLink::Display
    }

    fn node_find_tree_at(
        &self,
        x: i32,
        y: i32,
        tree: &mut Vec<FoundNode>,
        usecase: FindTreeUsecase,
    ) -> FindTreeResult {
        let outputs = self.outputs.lock();
        for output in outputs.values() {
            let pos = output.global.pos.get();
            if pos.contains(x, y) {
                let (x, y) = pos.translate(x, y);
                tree.push(FoundNode {
                    node: output.clone(),
                    x,
                    y,
                });
                output.node_find_tree_at(x, y, tree, usecase);
                break;
            }
        }
        FindTreeResult::AcceptsInput
    }

    fn node_render(&self, renderer: &mut Renderer, x: i32, y: i32, _bounds: Option<&Rect>) {
        renderer.render_display(self, x, y);
    }

    fn node_on_pointer_focus(&self, seat: &Rc<WlSeatGlobal>) {
        // log::info!("display focus");
        seat.pointer_cursor().set_known(KnownCursor::Default);
    }

    fn node_on_tablet_tool_enter(
        self: Rc<Self>,
        tool: &Rc<TabletTool>,
        _time_usec: u64,
        _x: Fixed,
        _y: Fixed,
    ) {
        tool.cursor().set_known(KnownCursor::Default)
    }
}