use super::WindowMap;
use rand;
use smithay::compositor::{compositor_init, CompositorToken, SurfaceAttributes, SurfaceUserImplementation};
use smithay::shell::{shell_init, PopupConfigure, ShellState, ShellSurfaceRole,
                     ShellSurfaceUserImplementation, ToplevelConfigure};
use smithay::shm::with_buffer_contents;
use std::cell::RefCell;
use std::rc::Rc;
use wayland_server::{EventLoop, StateToken};

define_roles!(Roles => [ ShellSurface, ShellSurfaceRole ] );

#[derive(Default)]
pub struct SurfaceData {
    pub buffer: Option<(Vec<u8>, (u32, u32))>,
}

pub fn surface_implementation() -> SurfaceUserImplementation<SurfaceData, Roles, ()> {
    SurfaceUserImplementation {
        commit: |_, _, surface, token| {
            // 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)))) => {
                        // we ignore hotspot coordinates in this simple example
                        with_buffer_contents(&buffer, |slice, data| {
                            let offset = data.offset as usize;
                            let stride = data.stride as usize;
                            let width = data.width as usize;
                            let height = data.height as usize;
                            let mut new_vec = Vec::with_capacity(width * height * 4);
                            for i in 0..height {
                                new_vec
                                    .extend(&slice[(offset + i * stride)..(offset + i * stride + width * 4)]);
                            }
                            attributes.user_data.buffer =
                                Some((new_vec, (data.width as u32, data.height as u32)));
                        }).unwrap();
                        buffer.release();
                    }
                    Some(None) => {
                        // erase the contents
                        attributes.user_data.buffer = None;
                    }
                    None => {}
                }
            });
        },
        frame: |_, _, _, callback, _| {
            callback.done(0);
        },
    }
}

pub struct ShellIData<F> {
    pub token: CompositorToken<SurfaceData, Roles, ()>,
    pub window_map: Rc<RefCell<super::WindowMap<SurfaceData, Roles, (), (), F>>>,
}

pub fn shell_implementation<F>() -> ShellSurfaceUserImplementation<SurfaceData, Roles, (), ShellIData<F>, ()>
where
    F: Fn(&SurfaceAttributes<SurfaceData>) -> Option<(i32, i32)>,
{
    ShellSurfaceUserImplementation {
        new_client: |_, _, _| {},
        client_pong: |_, _, _| {},
        new_toplevel: |_, idata, toplevel| {
            // 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);
            idata.window_map.borrow_mut().insert(toplevel, (x, y));
            ToplevelConfigure {
                size: None,
                states: vec![],
                serial: 42,
            }
        },
        new_popup: |_, _, _| {
            PopupConfigure {
                size: (10, 10),
                position: (10, 10),
                serial: 42,
            }
        },
        move_: |_, _, _, _, _| {},
        resize: |_, _, _, _, _, _| {},
        grab: |_, _, _, _, _| {},
        change_display_state: |_, _, _, _, _, _, _| {
            ToplevelConfigure {
                size: None,
                states: vec![],
                serial: 42,
            }
        },
        show_window_menu: |_, _, _, _, _, _, _| {},
    }
}

fn get_size(attrs: &SurfaceAttributes<SurfaceData>) -> Option<(i32, i32)> {
    attrs
        .user_data
        .buffer
        .as_ref()
        .map(|&(_, (w, h))| (w as i32, h as i32))
}

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

pub fn init_shell(
    evl: &mut EventLoop, log: ::slog::Logger)
    -> (
        CompositorToken<SurfaceData, Roles, ()>,
        StateToken<ShellState<SurfaceData, Roles, (), ()>>,
        Rc<RefCell<MyWindowMap>>,
    ) {
    let (compositor_token, _, _) = compositor_init(evl, surface_implementation(), (), log.clone());

    let window_map = Rc::new(RefCell::new(WindowMap::<_, _, _, (), _>::new(
        compositor_token,
        get_size as _,
    )));

    let (shell_state_token, _, _) = shell_init(
        evl,
        compositor_token,
        shell_implementation(),
        ShellIData {
            token: compositor_token,
            window_map: window_map.clone(),
        },
        log.clone(),
    );

    (compositor_token, shell_state_token, window_map)
}