use std::{
    cell::RefCell,
    rc::Rc,
    sync::{Arc, Mutex},
};

use rand;

use smithay::{
    wayland::{
        compositor::{compositor_init, CompositorToken, SurfaceAttributes, SurfaceEvent},
        data_device::DnDIconRole,
        seat::CursorImageRole,
        shell::{
            legacy::{
                wl_shell_init, ShellRequest, ShellState as WlShellState, ShellSurfaceKind, ShellSurfaceRole,
            },
            xdg::{
                xdg_shell_init, PopupConfigure, ShellState as XdgShellState, ToplevelConfigure, XdgRequest,
                XdgSurfaceRole,
            },
        },
    },
    reexports::wayland_server::{
        protocol::{wl_buffer, wl_callback, wl_shell_surface, wl_surface},
        Display, Resource,
    },
};

use crate::window_map::{Kind as SurfaceKind, WindowMap};

define_roles!(Roles =>
    [ XdgSurface, XdgSurfaceRole ]
    [ ShellSurface, ShellSurfaceRole<()>]
    [ DnDIcon, DnDIconRole ]
    [ CursorImage, CursorImageRole ]
);

pub type MyWindowMap =
    WindowMap<SurfaceData, Roles, (), (), fn(&SurfaceAttributes<SurfaceData>) -> Option<(i32, i32)>>;

pub type MyCompositorToken = CompositorToken<SurfaceData, Roles>;

pub fn init_shell(
    display: &mut Display,
    log: ::slog::Logger,
) -> (
    CompositorToken<SurfaceData, Roles>,
    Arc<Mutex<XdgShellState<SurfaceData, Roles, ()>>>,
    Arc<Mutex<WlShellState<SurfaceData, Roles, ()>>>,
    Rc<RefCell<MyWindowMap>>,
) {
    // Create the compositor
    let (compositor_token, _, _) = compositor_init(
        display,
        move |request, surface, ctoken| match request {
            SurfaceEvent::Commit => surface_commit(&surface, ctoken),
            SurfaceEvent::Frame { callback } => callback
                .implement(|e, _| match e {}, None::<fn(_)>, ())
                .send(wl_callback::Event::Done { callback_data: 0 }),
        },
        log.clone(),
    );

    // Init a window map, to track the location of our windows
    let window_map = Rc::new(RefCell::new(WindowMap::<_, _, (), (), _>::new(
        compositor_token,
        get_size as _,
    )));

    // init the xdg_shell
    let xdg_window_map = window_map.clone();
    let (xdg_shell_state, _, _) = xdg_shell_init(
        display,
        compositor_token,
        move |shell_event| match shell_event {
            XdgRequest::NewToplevel { surface } => {
                // place the window at a random location in the [0;800]x[0;800] square
                use rand::distributions::{IndependentSample, Range};
                let range = Range::new(0, 800);
                let mut rng = rand::thread_rng();
                let x = range.ind_sample(&mut rng);
                let y = range.ind_sample(&mut rng);
                surface.send_configure(ToplevelConfigure {
                    size: None,
                    states: vec![],
                    serial: 42,
                });
                xdg_window_map
                    .borrow_mut()
                    .insert(SurfaceKind::Xdg(surface), (x, y));
            }
            XdgRequest::NewPopup { surface } => surface.send_configure(PopupConfigure {
                size: (10, 10),
                position: (10, 10),
                serial: 42,
            }),
            _ => (),
        },
        log.clone(),
    );

    // init the wl_shell
    let shell_window_map = window_map.clone();
    let (wl_shell_state, _) = wl_shell_init(
        display,
        compositor_token,
        move |req: ShellRequest<_, _, ()>| {
            if let ShellRequest::SetKind {
                surface,
                kind: ShellSurfaceKind::Toplevel,
            } = req
            {
                // place the window at a random location in the [0;300]x[0;300] square
                use rand::distributions::{IndependentSample, Range};
                let range = Range::new(0, 300);
                let mut rng = rand::thread_rng();
                let x = range.ind_sample(&mut rng);
                let y = range.ind_sample(&mut rng);
                surface.send_configure((0, 0), wl_shell_surface::Resize::None);
                shell_window_map
                    .borrow_mut()
                    .insert(SurfaceKind::Wl(surface), (x, y));
            }
        },
        log.clone(),
    );

    (compositor_token, xdg_shell_state, wl_shell_state, window_map)
}

#[derive(Default)]
pub struct SurfaceData {
    pub buffer: Option<Resource<wl_buffer::WlBuffer>>,
    pub texture: Option<crate::glium_drawer::TextureMetadata>,
}

fn surface_commit(surface: &Resource<wl_surface::WlSurface>, token: CompositorToken<SurfaceData, Roles>) {
    // we retrieve the contents of the associated buffer and copy it
    token.with_surface_data(surface, |attributes| {
        match attributes.buffer.take() {
            Some(Some((buffer, (_x, _y)))) => {
                // new contents
                // TODO: handle hotspot coordinates
                attributes.user_data.buffer = Some(buffer);
                attributes.user_data.texture = None;
            }
            Some(None) => {
                // erase the contents
                attributes.user_data.buffer = None;
                attributes.user_data.texture = None;
            }
            None => {}
        }
    });
}

fn get_size(attrs: &SurfaceAttributes<SurfaceData>) -> Option<(i32, i32)> {
    attrs
        .user_data
        .texture
        .as_ref()
        .map(|ref meta| meta.dimensions)
        .map(|(x, y)| (x as i32, y as i32))
}