use std::sync::{Arc, Mutex, Weak};

use wayland_client::protocol::{wl_display,wl_surface};
use wayland_client::{Proxy, StateToken};

use {CreationError, MouseCursor, CursorState, WindowAttributes};
use platform::MonitorId as PlatformMonitorId;
use window::MonitorId as RootMonitorId;

use super::{EventsLoop, WindowId, make_wid, MonitorId};
use super::wayland_window::{Frame, FrameImplementation, State as FrameState};
use super::event_loop::StateContext;

pub struct Window {
    surface: wl_surface::WlSurface,
    frame: Arc<Mutex<Frame>>,
    monitors: Arc<Mutex<MonitorList>>,
    size: Arc<Mutex<(u32, u32)>>,
    kill_switch: (Arc<Mutex<bool>>, Arc<Mutex<bool>>),
    display: Arc<wl_display::WlDisplay>,
}

impl Window {
    pub fn new(evlp: &EventsLoop, attributes: &WindowAttributes) -> Result<Window, CreationError>
    {
        let (width, height) = attributes.dimensions.unwrap_or((800,600));

        // Create the decorated surface
        let size = Arc::new(Mutex::new((width, height)));
        let store_token = evlp.store.clone();
        let (surface, mut frame) = evlp.create_window(
            width, height, decorated_impl(),
            |surface| FrameIData {
                surface: surface.clone().unwrap(),
                store_token: store_token.clone()
            }
        );
        // Check for fullscreen requirements
        if let Some(RootMonitorId { inner: PlatformMonitorId::Wayland(ref monitor_id) }) = attributes.fullscreen {
            let info = monitor_id.info.lock().unwrap();
            frame.set_state(FrameState::Fullscreen(Some(&info.output)));
        } else if attributes.maximized {
            frame.set_state(FrameState::Maximized);
        }

        // set decorations
        frame.set_decorate(attributes.decorations);

        // min-max dimensions
        frame.set_min_size(attributes.min_dimensions.map(|(w, h)| (w as i32, h as i32)));
        frame.set_max_size(attributes.max_dimensions.map(|(w, h)| (w as i32, h as i32)));

        // setup the monitor tracking
        let monitor_list = Arc::new(Mutex::new(MonitorList::default()));
        {
            let mut evq = evlp.evq.borrow_mut();
            let idata = (evlp.ctxt_token.clone(), monitor_list.clone());
            evq.register(&surface, surface_impl(), idata);
        }

        let kill_switch = Arc::new(Mutex::new(false));
        let frame = Arc::new(Mutex::new(frame));

        {
            let mut evq = evlp.evq.borrow_mut();
            evq.state().get_mut(&store_token).windows.push(InternalWindow {
                closed: false,
                newsize: None,
                need_refresh: false,
                need_frame_refresh: true,
                surface: surface.clone().unwrap(),
                kill_switch: kill_switch.clone(),
                frame: Arc::downgrade(&frame)
            });
            evq.sync_roundtrip().unwrap();
        }

        Ok(Window {
            display: evlp.display.clone(),
            surface: surface,
            frame: frame,
            monitors: monitor_list,
            size: size,
            kill_switch: (kill_switch, evlp.cleanup_needed.clone())
        })
    }

    #[inline]
    pub fn id(&self) -> WindowId {
        make_wid(&self.surface)
    }

    pub fn set_title(&self, title: &str) {
        self.frame.lock().unwrap().set_title(title.into());
    }

    #[inline]
    pub fn show(&self) {
        // TODO
    }

    #[inline]
    pub fn hide(&self) {
        // TODO
    }

    #[inline]
    pub fn get_position(&self) -> Option<(i32, i32)> {
        // Not possible with wayland
        None
    }

    #[inline]
    pub fn set_position(&self, _x: i32, _y: i32) {
        // Not possible with wayland
    }

    pub fn get_inner_size(&self) -> Option<(u32, u32)> {
        Some(self.size.lock().unwrap().clone())
    }

    #[inline]
    pub fn get_outer_size(&self) -> Option<(u32, u32)> {
        let (w, h) = self.size.lock().unwrap().clone();
        let (w, h) = super::wayland_window::add_borders(w as i32, h as i32);
        Some((w as u32, h as u32))
    }

    #[inline]
    // NOTE: This will only resize the borders, the contents must be updated by the user
    pub fn set_inner_size(&self, x: u32, y: u32) {
        self.frame.lock().unwrap().resize(x as i32, y as i32);
        *(self.size.lock().unwrap()) = (x, y);
    }

    #[inline]
    pub fn set_cursor(&self, _cursor: MouseCursor) {
        // TODO
    }

    #[inline]
    pub fn set_cursor_state(&self, state: CursorState) -> Result<(), String> {
        use CursorState::{Grab, Normal, Hide};
        // TODO : not yet possible on wayland to grab cursor
        match state {
            Grab => Err("Cursor cannot be grabbed on wayland yet.".to_string()),
            Hide => Err("Cursor cannot be hidden on wayland yet.".to_string()),
            Normal => Ok(())
        }
    }

    #[inline]
    pub fn hidpi_factor(&self) -> f32 {
        let mut factor = 1.0;
        let guard = self.monitors.lock().unwrap();
        for monitor_id in &guard.monitors {
            let info = monitor_id.info.lock().unwrap();
            if info.scale > factor { factor = info.scale; }
        }
        factor
    }

    #[inline]
    pub fn set_cursor_position(&self, _x: i32, _y: i32) -> Result<(), ()> {
        // TODO: not yet possible on wayland
        Err(())
    }
    
    pub fn get_display(&self) -> &wl_display::WlDisplay {
        &*self.display
    }
    
    pub fn get_surface(&self) -> &wl_surface::WlSurface {
        &self.surface
    }

    pub fn get_current_monitor(&self) -> MonitorId {
        // we don't know how much each monitor sees us so...
        // just return the most recent one ?
        let guard = self.monitors.lock().unwrap();
        guard.monitors.last().unwrap().clone()
    }
}

impl Drop for Window {
    fn drop(&mut self) {
        *(self.kill_switch.0.lock().unwrap()) = true;
        *(self.kill_switch.1.lock().unwrap()) = true;
    }
}

/*
 * Internal store for windows
 */

struct InternalWindow {
    surface: wl_surface::WlSurface,
    newsize: Option<(i32, i32)>,
    need_refresh: bool,
    need_frame_refresh: bool,
    closed: bool,
    kill_switch: Arc<Mutex<bool>>,
    frame: Weak<Mutex<Frame>>
}

pub struct WindowStore {
    windows: Vec<InternalWindow>
}

impl WindowStore {
    pub fn new() -> WindowStore {
        WindowStore { windows: Vec::new() }
    }

    pub fn find_wid(&self, surface: &wl_surface::WlSurface) -> Option<WindowId> {
        for window in &self.windows {
            if surface.equals(&window.surface) {
                return Some(make_wid(surface));
            }
        }
        None
    }

    pub fn cleanup(&mut self) {
        self.windows.retain(|w| {
            if *w.kill_switch.lock().unwrap() {
                // window is dead, cleanup
                w.surface.destroy();
                false
            } else {
                true
            }
        });
    }

    pub fn for_each<F>(&mut self, mut f: F)
    where F: FnMut(Option<(i32, i32)>, bool, bool, bool, WindowId, Option<&mut Frame>)
    {
        for window in &mut self.windows {
            let opt_arc = window.frame.upgrade();
            let mut opt_mutex_lock = opt_arc.as_ref().map(|m| m.lock().unwrap());
            f(
                window.newsize.take(),
                window.need_refresh,
                window.need_frame_refresh,
                window.closed,
                make_wid(&window.surface),
                opt_mutex_lock.as_mut().map(|m| &mut **m)
            );
            window.need_refresh = false;
            // avoid re-spamming the event
            window.closed = false;
        }
    }
}

/*
 * Protocol implementation
 */

struct FrameIData {
    store_token: StateToken<WindowStore>,
    surface: wl_surface::WlSurface
}

fn decorated_impl() -> FrameImplementation<FrameIData> {
    FrameImplementation {
        configure: |evqh, idata, _, newsize| {
            let store = evqh.state().get_mut(&idata.store_token);
            for window in &mut store.windows {
                if window.surface.equals(&idata.surface) {
                    window.newsize = newsize;
                    window.need_refresh = true;
                    window.need_frame_refresh = true;
                    return;
                }
            }
        },
        close: |evqh, idata| {
            let store = evqh.state().get_mut(&idata.store_token);
            for window in &mut store.windows {
                if window.surface.equals(&idata.surface) {
                    window.closed = true;
                    return;
                }
            }
        },
        refresh: |evqh, idata| {
            let store = evqh.state().get_mut(&idata.store_token);
            for window in &mut store.windows {
                if window.surface.equals(&idata.surface) {
                    window.need_frame_refresh = true;
                    return;
                }
            }
        }
    }
}

#[derive(Default)]
struct MonitorList {
    monitors: Vec<MonitorId>
}

fn surface_impl() -> wl_surface::Implementation<(StateToken<StateContext>, Arc<Mutex<MonitorList>>)> {
    wl_surface::Implementation {
        enter: |evqh, &mut (ref token, ref list), _, output| {
            let mut guard = list.lock().unwrap();
            let ctxt = evqh.state().get(token);
            let monitor = ctxt.monitor_id_for(output);
            guard.monitors.push(monitor);
        },
        leave: |evqh, &mut (ref token, ref list), _, output| {
            let mut guard = list.lock().unwrap();
            let ctxt = evqh.state().get(token);
            let monitor = ctxt.monitor_id_for(output);
            guard.monitors.retain(|m| !Arc::ptr_eq(&m.info, &monitor.info));
        }
    }
}