use crate::client::{Client, ClientError};
use crate::ifs::wl_seat::NodeSeatState;
use crate::ifs::wl_surface::{
    CommitAction, CommitContext, SurfaceExt, SurfaceRole, WlSurface, WlSurfaceError,
};
use crate::ifs::zwlr_layer_shell_v1::{ZwlrLayerShellV1, OVERLAY};
use crate::leaks::Tracker;
use crate::object::Object;
use crate::rect::Rect;
use crate::render::Renderer;
use crate::tree::walker::NodeVisitor;
use crate::tree::{FindTreeResult, FoundNode, Node, NodeId, OutputNode};
use crate::utils::bitflags::BitflagsExt;
use crate::utils::buffd::MsgParser;
use crate::utils::buffd::MsgParserError;
use crate::utils::linkedlist::LinkedNode;
use crate::wire::zwlr_layer_surface_v1::*;
use crate::wire::{WlSurfaceId, ZwlrLayerSurfaceV1Id};
use crate::NumCell;
use std::cell::Cell;
use std::ops::Deref;
use std::rc::Rc;
use thiserror::Error;

const KI_NONE: u32 = 0;
#[allow(dead_code)]
const KI_EXCLUSIVE: u32 = 1;
const KI_ON_DEMAND: u32 = 2;

const TOP: u32 = 1;
const BOTTOM: u32 = 2;
const LEFT: u32 = 4;
const RIGHT: u32 = 8;

tree_id!(ZwlrLayerSurfaceV1NodeId);
pub struct ZwlrLayerSurfaceV1 {
    pub id: ZwlrLayerSurfaceV1Id,
    node_id: ZwlrLayerSurfaceV1NodeId,
    pub shell: Rc<ZwlrLayerShellV1>,
    pub client: Rc<Client>,
    pub surface: Rc<WlSurface>,
    pub output: Rc<OutputNode>,
    pub namespace: String,
    pub tracker: Tracker<Self>,
    pos: Cell<Rect>,
    mapped: Cell<bool>,
    layer: Cell<u32>,
    pending: Pending,
    requested_serial: NumCell<u32>,
    acked_serial: Cell<Option<u32>>,
    size: Cell<(i32, i32)>,
    anchor: Cell<u32>,
    exclusive_zone: Cell<i32>,
    margin: Cell<(i32, i32, i32, i32)>,
    keyboard_interactivity: Cell<u32>,
    link: Cell<Option<LinkedNode<Rc<Self>>>>,
    seat_state: NodeSeatState,
}

#[derive(Default)]
struct Pending {
    size: Cell<Option<(i32, i32)>>,
    anchor: Cell<Option<u32>>,
    exclusive_zone: Cell<Option<i32>>,
    margin: Cell<Option<(i32, i32, i32, i32)>>,
    keyboard_interactivity: Cell<Option<u32>>,
    layer: Cell<Option<u32>>,
}

impl ZwlrLayerSurfaceV1 {
    pub fn new(
        id: ZwlrLayerSurfaceV1Id,
        shell: &Rc<ZwlrLayerShellV1>,
        surface: &Rc<WlSurface>,
        output: &Rc<OutputNode>,
        layer: u32,
        namespace: &str,
    ) -> Self {
        Self {
            id,
            node_id: shell.client.state.node_ids.next(),
            shell: shell.clone(),
            client: shell.client.clone(),
            surface: surface.clone(),
            output: output.clone(),
            namespace: namespace.to_string(),
            tracker: Default::default(),
            pos: Cell::new(Default::default()),
            mapped: Cell::new(false),
            layer: Cell::new(layer),
            pending: Default::default(),
            requested_serial: Default::default(),
            acked_serial: Cell::new(None),
            size: Cell::new((0, 0)),
            anchor: Cell::new(0),
            exclusive_zone: Cell::new(0),
            margin: Cell::new((0, 0, 0, 0)),
            keyboard_interactivity: Cell::new(0),
            link: Cell::new(None),
            seat_state: Default::default(),
        }
    }

    pub fn install(self: &Rc<Self>) -> Result<(), ZwlrLayerSurfaceV1Error> {
        self.surface.set_role(SurfaceRole::ZwlrLayerSurface)?;
        if self.surface.ext.get().is_some() {
            return Err(ZwlrLayerSurfaceV1Error::AlreadyAttached(self.surface.id));
        }
        self.surface.ext.set(self.clone());
        Ok(())
    }

    fn send_configure(&self, serial: u32, width: u32, height: u32) {
        self.client.event(Configure {
            self_id: self.id,
            serial,
            width,
            height,
        });
    }

    #[allow(dead_code)]
    fn send_closed(&self) {
        self.client.event(Closed { self_id: self.id });
    }

    fn set_size(&self, parser: MsgParser<'_, '_>) -> Result<(), SetSizeError> {
        let req: SetSize = self.client.parse(self, parser)?;
        if req.width > u16::MAX as u32 || req.height > u16::MAX as u32 {
            return Err(SetSizeError::ExcessiveSize);
        }
        self.pending
            .size
            .set(Some((req.width as _, req.height as _)));
        Ok(())
    }

    fn set_anchor(&self, parser: MsgParser<'_, '_>) -> Result<(), SetAnchorError> {
        let req: SetAnchor = self.client.parse(self, parser)?;
        if req.anchor & !(LEFT | RIGHT | TOP | BOTTOM) != 0 {
            return Err(SetAnchorError::UnknownAnchor(req.anchor));
        }
        self.pending.anchor.set(Some(req.anchor));
        Ok(())
    }

    fn set_exclusive_zone(&self, parser: MsgParser<'_, '_>) -> Result<(), SetExclusiveZoneError> {
        let req: SetExclusiveZone = self.client.parse(self, parser)?;
        self.pending.exclusive_zone.set(Some(req.zone));
        Ok(())
    }

    fn set_margin(&self, parser: MsgParser<'_, '_>) -> Result<(), SetMarginError> {
        let req: SetMargin = self.client.parse(self, parser)?;
        self.pending
            .margin
            .set(Some((req.top, req.right, req.bottom, req.left)));
        Ok(())
    }

    fn set_keyboard_interactivity(
        &self,
        parser: MsgParser<'_, '_>,
    ) -> Result<(), SetKeyboardInteractivityError> {
        let req: SetKeyboardInteractivity = self.client.parse(self, parser)?;
        if req.keyboard_interactivity > KI_ON_DEMAND {
            return Err(SetKeyboardInteractivityError::UnknownKi(
                req.keyboard_interactivity,
            ));
        }
        self.pending
            .keyboard_interactivity
            .set(Some(req.keyboard_interactivity));
        Ok(())
    }

    fn get_popup(&self, parser: MsgParser<'_, '_>) -> Result<(), GetPopupError> {
        let _req: GetPopup = self.client.parse(self, parser)?;
        Ok(())
    }

    fn ack_configure(&self, parser: MsgParser<'_, '_>) -> Result<(), AckConfigureError> {
        let req: AckConfigure = self.client.parse(self, parser)?;
        self.acked_serial.set(Some(req.serial));
        Ok(())
    }

    fn destroy(&self, parser: MsgParser<'_, '_>) -> Result<(), DestroyError> {
        let _req: Destroy = self.client.parse(self, parser)?;
        self.destroy_node(true);
        self.client.remove_obj(self)?;
        self.surface.unset_ext();
        Ok(())
    }

    fn set_layer(&self, parser: MsgParser<'_, '_>) -> Result<(), SetLayerError> {
        let req: SetLayer = self.client.parse(self, parser)?;
        if req.layer > OVERLAY {
            return Err(SetLayerError::UnknownLayer(req.layer));
        }
        self.pending.layer.set(Some(req.layer));
        Ok(())
    }

    fn pre_commit(&self) -> Result<(), ZwlrLayerSurfaceV1Error> {
        let mut send_configure = false;
        if let Some(size) = self.pending.size.take() {
            self.size.set(size);
        }
        if let Some(anchor) = self.pending.anchor.take() {
            self.anchor.set(anchor);
        }
        if let Some(ez) = self.pending.exclusive_zone.take() {
            self.exclusive_zone.set(ez);
        }
        if let Some(margin) = self.pending.margin.take() {
            self.margin.set(margin);
        }
        if let Some(ki) = self.pending.keyboard_interactivity.take() {
            self.keyboard_interactivity.set(ki);
        }
        if let Some(layer) = self.pending.layer.take() {
            self.layer.set(layer);
        }
        {
            let (mut width, mut height) = self.size.get();
            let anchor = self.anchor.get();
            if width == 0 {
                if !anchor.contains(LEFT | RIGHT) {
                    return Err(ZwlrLayerSurfaceV1Error::WidthZero);
                }
                send_configure = true;
                width = self.output.global.position().width();
            }
            if height == 0 {
                if !anchor.contains(TOP | BOTTOM) {
                    return Err(ZwlrLayerSurfaceV1Error::HeightZero);
                }
                send_configure = true;
                height = self.output.global.position().height();
            }
            self.size.set((width, height));
        }
        if self.acked_serial.get().is_none() {
            send_configure = true;
        }
        if send_configure {
            let (width, height) = self.size.get();
            let serial = self.requested_serial.fetch_add(1) + 1;
            self.send_configure(serial, width as _, height as _);
        }
        Ok(())
    }

    pub fn position(&self) -> Rect {
        self.pos.get()
    }

    fn compute_position(&self) {
        let (width, height) = self.size.get();
        let mut anchor = self.anchor.get();
        if anchor == 0 {
            anchor = LEFT | RIGHT | TOP | BOTTOM;
        }
        let opos = self.output.position.get();
        let mut x1 = opos.x1();
        let mut y1 = opos.y1();
        if anchor.contains(LEFT) {
            if anchor.contains(RIGHT) {
                x1 += (opos.width() - width) / 2;
            }
        } else if anchor.contains(RIGHT) {
            x1 += opos.width() - width;
        }
        if anchor.contains(TOP) {
            if anchor.contains(BOTTOM) {
                y1 += (opos.height() - height) / 2;
            }
        } else if anchor.contains(BOTTOM) {
            y1 += opos.height() - height;
        }
        self.pos
            .set(Rect::new_sized(x1, y1, width, height).unwrap());
        self.client.state.tree_changed();
    }
}

impl SurfaceExt for ZwlrLayerSurfaceV1 {
    fn pre_commit(self: Rc<Self>, _ctx: CommitContext) -> Result<CommitAction, WlSurfaceError> {
        self.deref().pre_commit()?;
        Ok(CommitAction::ContinueCommit)
    }

    fn post_commit(self: Rc<Self>) {
        let buffer = self.surface.buffer.get();
        if self.mapped.get() {
            if buffer.is_none() {
                self.destroy_node(true);
            } else {
                let pos = self.pos.get();
                let (width, height) = self.size.get();
                if width != pos.width() || height != pos.height() {
                    self.compute_position();
                }
            }
        } else if buffer.is_some() {
            let layer = &self.output.layers[self.layer.get() as usize];
            self.link.set(Some(layer.add_last(self.clone())));
            self.mapped.set(true);
            self.compute_position();
        }
        if self.mapped.get() {
            match self.keyboard_interactivity.get() {
                KI_NONE => {
                    let was_active = self.surface.seat_state.is_active();
                    self.surface.seat_state.release_kb_focus();
                    if was_active {
                        self.surface.active_changed(false);
                    }
                }
                KI_ON_DEMAND => self.surface.seat_state.release_kb_grab(),
                KI_EXCLUSIVE => {
                    let seats = self.client.state.globals.seats.lock();
                    for seat in seats.values() {
                        seat.grab(self.surface.clone());
                    }
                }
                _ => unreachable!(),
            }
        }
    }

    fn accepts_kb_focus(&self) -> bool {
        self.keyboard_interactivity.get() != KI_NONE
    }
}

impl Node for ZwlrLayerSurfaceV1 {
    fn id(&self) -> NodeId {
        self.node_id.into()
    }

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

    fn destroy_node(&self, _detach: bool) {
        self.link.set(None);
        self.mapped.set(false);
        self.surface.destroy_node(false);
        self.seat_state.destroy_node(self);
    }

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

    fn visit_children(&self, visitor: &mut dyn NodeVisitor) {
        self.surface.clone().visit(visitor);
    }

    fn render(&self, renderer: &mut Renderer, x: i32, y: i32) {
        renderer.render_layer_surface(self, x, y);
    }

    fn absolute_position(&self) -> Rect {
        self.pos.get()
    }

    fn find_tree_at(&self, x: i32, y: i32, tree: &mut Vec<FoundNode>) -> FindTreeResult {
        tree.push(FoundNode {
            node: self.surface.clone(),
            x,
            y,
        });
        self.surface.find_tree_at(x, y, tree)
    }

    fn change_extents(self: Rc<Self>, _rect: &Rect) {
        self.compute_position();
    }
}

object_base! {
    ZwlrLayerSurfaceV1, ZwlrLayerSurfaceV1Error;

    SET_SIZE                   => set_size,
    SET_ANCHOR                 => set_anchor,
    SET_EXCLUSIVE_ZONE         => set_exclusive_zone,
    SET_MARGIN                 => set_margin,
    SET_KEYBOARD_INTERACTIVITY => set_keyboard_interactivity,
    GET_POPUP                  => get_popup,
    ACK_CONFIGURE              => ack_configure,
    DESTROY                    => destroy,
    SET_LAYER                  => set_layer,
}

impl Object for ZwlrLayerSurfaceV1 {
    fn num_requests(&self) -> u32 {
        let last_req = match self.shell.version {
            0..=1 => DESTROY,
            _ => SET_LAYER,
        };
        last_req + 1
    }

    fn break_loops(&self) {
        self.destroy_node(true);
        self.link.set(None);
    }
}

simple_add_obj!(ZwlrLayerSurfaceV1);

#[derive(Debug, Error)]
pub enum ZwlrLayerSurfaceV1Error {
    #[error("Could not process `set_size` request")]
    SetSizeError(#[from] SetSizeError),
    #[error("Could not process `set_anchor` request")]
    SetAnchorError(#[from] SetAnchorError),
    #[error("Could not process `set_exclusive_zone` request")]
    SetExclusiveZoneError(#[from] SetExclusiveZoneError),
    #[error("Could not process `set_margin` request")]
    SetMarginError(#[from] SetMarginError),
    #[error("Could not process `set_keyboard_interactivity` request")]
    SetKeyboardInteractivityError(#[from] SetKeyboardInteractivityError),
    #[error("Could not process `get_popup` request")]
    GetPopupError(#[from] GetPopupError),
    #[error("Could not process `ack_configure` request")]
    AckConfigureError(#[from] AckConfigureError),
    #[error("Could not process `destroy` request")]
    DestroyError(#[from] DestroyError),
    #[error("Could not process `set_layer` request")]
    SetLayerError(#[from] SetLayerError),
    #[error("Surface {0} cannot be turned into a zwlr_layer_surface because it already has an attached zwlr_layer_surface")]
    AlreadyAttached(WlSurfaceId),
    #[error("Width was set to 0 but anchor did not contain LEFT and RIGHT")]
    WidthZero,
    #[error("Height was set to 0 but anchor did not contain TOP and BOTTOM")]
    HeightZero,
    #[error(transparent)]
    WlSurfaceError(Box<WlSurfaceError>),
}
efrom!(ZwlrLayerSurfaceV1Error, WlSurfaceError);

#[derive(Debug, Error)]
pub enum SetSizeError {
    #[error("Parsing failed")]
    MsgParserError(#[source] Box<MsgParserError>),
    #[error(transparent)]
    ClientError(Box<ClientError>),
    #[error("Surface size must not be larger than 65535x65535")]
    ExcessiveSize,
}
efrom!(SetSizeError, MsgParserError);
efrom!(SetSizeError, ClientError);

#[derive(Debug, Error)]
pub enum SetAnchorError {
    #[error("Parsing failed")]
    MsgParserError(#[source] Box<MsgParserError>),
    #[error(transparent)]
    ClientError(Box<ClientError>),
    #[error("Unknown anchor {0}")]
    UnknownAnchor(u32),
}
efrom!(SetAnchorError, MsgParserError);
efrom!(SetAnchorError, ClientError);

#[derive(Debug, Error)]
pub enum SetExclusiveZoneError {
    #[error("Parsing failed")]
    MsgParserError(#[source] Box<MsgParserError>),
    #[error(transparent)]
    ClientError(Box<ClientError>),
}
efrom!(SetExclusiveZoneError, MsgParserError);
efrom!(SetExclusiveZoneError, ClientError);

#[derive(Debug, Error)]
pub enum SetMarginError {
    #[error("Parsing failed")]
    MsgParserError(#[source] Box<MsgParserError>),
    #[error(transparent)]
    ClientError(Box<ClientError>),
}
efrom!(SetMarginError, MsgParserError);
efrom!(SetMarginError, ClientError);

#[derive(Debug, Error)]
pub enum SetKeyboardInteractivityError {
    #[error("Parsing failed")]
    MsgParserError(#[source] Box<MsgParserError>),
    #[error(transparent)]
    ClientError(Box<ClientError>),
    #[error("Unknown keyboard interactivity {0}")]
    UnknownKi(u32),
}
efrom!(SetKeyboardInteractivityError, MsgParserError);
efrom!(SetKeyboardInteractivityError, ClientError);

#[derive(Debug, Error)]
pub enum GetPopupError {
    #[error("Parsing failed")]
    MsgParserError(#[source] Box<MsgParserError>),
    #[error(transparent)]
    ClientError(Box<ClientError>),
}
efrom!(GetPopupError, MsgParserError);
efrom!(GetPopupError, ClientError);

#[derive(Debug, Error)]
pub enum AckConfigureError {
    #[error("Parsing failed")]
    MsgParserError(#[source] Box<MsgParserError>),
    #[error(transparent)]
    ClientError(Box<ClientError>),
}
efrom!(AckConfigureError, MsgParserError);
efrom!(AckConfigureError, ClientError);

#[derive(Debug, Error)]
pub enum DestroyError {
    #[error("Parsing failed")]
    MsgParserError(#[source] Box<MsgParserError>),
    #[error(transparent)]
    ClientError(Box<ClientError>),
}
efrom!(DestroyError, MsgParserError);
efrom!(DestroyError, ClientError);

#[derive(Debug, Error)]
pub enum SetLayerError {
    #[error("Parsing failed")]
    MsgParserError(#[source] Box<MsgParserError>),
    #[error(transparent)]
    ClientError(Box<ClientError>),
    #[error("Unknown layer {0}")]
    UnknownLayer(u32),
}
efrom!(SetLayerError, MsgParserError);
efrom!(SetLayerError, ClientError);