// See LICENSE file for copyright and license details.

use x11::xlib;
use x11::xlib::{
    Display,
    XErrorEvent,
    Atom,
    XChangeProperty,
};

use safe_x11::{
    open_display,
    close_display,
    atom,
};

use safe_x11::window::{
    XWindow,
};
use desktop::Desktop;

use std::ptr;
use std::process::exit;
use std::mem::uninitialized;
use std::collections::HashMap;
use libc::c_int;
use libc::c_char;

#[allow(unused_variables)]
unsafe extern "C" fn error_handler(d: *mut Display, evptr: *mut XErrorEvent) -> c_int {
    println!("ERROR");
    let ev = ptr::read(evptr);
    if ev.error_code == xlib::BadAccess {
        println!("Another widnow manager is running :C");
        exit(1);
    }

    println!("Error code {:?}", ev.error_code);
    let mut buf: [i8; 1000] = [0i8; 1000];
    let bufptr = buf.as_mut_ptr();
    xlib::XGetErrorText(d, ev.error_code as c_int, bufptr as *mut c_char, 1000);
    let string = String::from_raw_parts(bufptr as *mut u8, 1000, 1000);
    println!("Error: {}", string);

    0
}

#[derive(Hash,Eq,PartialEq)]
pub enum WmAtom {
    Protocols,
    DeleteWindow,
}

#[derive(Hash,Eq,PartialEq)]
pub enum NetAtom {
    NetSupported,
    NetFullscreen,
    NetWmState,
    NetActive,
}

/// State of the window manager.
pub struct DotWM {
    /// Reference to the X display.
    pub display: *mut Display,
    /// Check if the window manager needs to end.
    pub finish: bool,
    /// Vec holding atoms for ICCCM support
    pub wmatoms: HashMap<WmAtom, Atom>,
    /// Vec holding atoms for EWHM support
    pub netatoms: HashMap<NetAtom, Atom>,
    /// Number of the active desctop
    pub desktop_idx: usize,
    /// Desktops
    pub desktops: Vec<Desktop>,
}

/// DotWM state.
impl DotWM {
    /// Create a state of the Dot Window Manager
    pub fn new() -> DotWM {
        let d = open_display("").unwrap();
        unsafe { xlib::XSetErrorHandler(Some(error_handler)) };

        // Add substructure notify mask
        let root = unsafe { xlib::XDefaultRootWindow(d) };

        unsafe {
            let mut attrs: xlib::XSetWindowAttributes = uninitialized();
            attrs.event_mask = xlib::SubstructureNotifyMask;
            xlib::XChangeWindowAttributes(d, root, xlib::CWEventMask, &mut attrs);
        }

        // Get the wmatoms
        let mut wmatoms = HashMap::new();
        wmatoms.insert(WmAtom::Protocols, atom(d, "WM_PROTOCOLS"));
        wmatoms.insert(WmAtom::DeleteWindow, atom(d, "WM_DELETE_WINDOW"));

        // Get the netatoms
        let mut netatoms = HashMap::new();
        netatoms.insert(NetAtom::NetSupported, atom(d, "_NET_SUPPORTED"));
        netatoms.insert(NetAtom::NetFullscreen, atom(d, "_NET_WM_STATE_FULLSCREEN"));
        netatoms.insert(NetAtom::NetWmState, atom(d, "_NET_ACTIVE_WINDOW"));
        netatoms.insert(NetAtom::NetActive, atom(d, "_NET_WM_STATE"));

        // Propagate EWHM support
        unsafe {
            let atomvec: Vec<&Atom> = netatoms.values().collect();
            let len: i32 = netatoms.len() as i32;
            let atomptr = atomvec.as_ptr();

            XChangeProperty(d, root, netatoms[&NetAtom::NetSupported], xlib::XA_ATOM,
                            32, xlib::PropModeReplace, atomptr as *const u8, len);
        }

        DotWM {
            display: d,
            finish: false,
            wmatoms: wmatoms,
            netatoms: netatoms,
            desktop_idx: 0,
            desktops: vec![
                Desktop::new(d, "main"),
                Desktop::new(d, "other")
            ],
        }
    }

    /// this should always return a desktop.
    pub fn current_desktop_mut(&mut self) -> &mut Desktop {
        self.desktops.get_mut(self.desktop_idx).unwrap()
    }

    pub fn current_desktop(&self) -> &Desktop {
        self.desktops.get(self.desktop_idx).unwrap()
    }
    
    /// Add a window to the current desktop
    pub fn add_window(&mut self, w: xlib::Window) {
        self.current_desktop_mut().add_window(w);
    }

    pub fn current_window(&self) -> Option<&XWindow> {
        let d = self.desktops.get(self.desktop_idx);
        if let Some(desktop) = d {
            desktop.current_window()
        } else {
            None
        }
    }

    pub fn current_window_mut(&mut self) -> Option<&mut XWindow> {
        let d = self.desktops.get_mut(self.desktop_idx);
        if let Some(desktop) = d {
            desktop.current_window_mut()
        } else {
            None
        }
    }

    pub fn remove_window(&mut self, w: xlib::Window) {
        //let iter = self.desktops.iter_mut();
        //for desktop in iter {
        //    desktop.remove_window(w);
        //}
        self.current_desktop_mut().remove_window(w);
    }

    pub fn change_focus_of(&mut self, idx: usize) {
        self.current_desktop_mut().change_focus_of(idx);
    }

    /// Find a given window and returns it's position on the window_list.
    pub fn find_window(&self, w: xlib::Window) -> Option<usize> {
        self.current_desktop().find_window(w)
    }

    /// Focus the next window.
    ///
    /// There're 3 posibilities. There's no window, there's one window or there
    /// are more windows.
    pub fn focus_next(&mut self) {
        self.current_desktop_mut().focus_next();
    }

    pub fn x_geometries(&self) -> Vec<i32> {
        self.current_desktop().geometries().iter().map(|x| x.0).collect()
    }

    pub fn y_geometries(&self) -> Vec<i32> {
        self.current_desktop().geometries().iter().map(|x| x.1).collect()
    }

    pub fn change_desktop(&mut self,desktop: usize) {
        if desktop > self.desktops.len() {
            return;
        }

        if desktop == self.desktop_idx {
            return;
        }

        let new_desktop = &self.desktops[desktop];
        let old_desktop = &self.desktops[self.desktop_idx];

        new_desktop.show_windows();
        // let mut do_not_propagate: xlib::XSetWindowAttributes = unsafe { uninitialized() };
        // let root = root_window(self.display);
        // do_not_propagate.do_not_propagate_mask = xlib::SubstructureNotifyMask;
        // change_window_attributes(self.display, root, xlib::CWEventMask,
        //                          &mut do_not_propagate);

        old_desktop.hide_windows();
        // let mut root_mask: xlib::XSetWindowAttributes = unsafe { uninitialized() };
        // root_mask.event_mask = xlib::SubstructureRedirectMask|xlib::ButtonPressMask|xlib::SubstructureNotifyMask|xlib::PropertyChangeMask;
        // change_window_attributes(self.display, root, xlib::CWEventMask,
        //                          &mut root_mask);
        self.desktop_idx = desktop;
    }
}

impl Drop for DotWM {
    fn drop(&mut self) {
        close_display(self.display);
    }
}