// See LICENSE file for copyright and license details.

use x11::xlib;
use x11::xlib::{
    Window,
    XWindowAttributes,
    XGetWindowAttributes,
    XDefaultScreenOfDisplay,
    XMoveWindow, XMoveResizeWindow,

    XDisplayHeight, XDisplayWidth, XDefaultScreen,
    XA_ATOM, Atom, PropModeReplace,

    XSetInputFocus,
    XSetWindowBorder,

    IsViewable, RevertToParent, CurrentTime,

    XEvent, XSendEvent, XClientMessageEvent,
    ClientMessage,ClientMessageData, NoEventMask,

    XChangeProperty,
    XChangeWindowAttributes, XSetWindowAttributes,

    XMapWindow, XUnmapWindow,

    XBlackPixel,XWhitePixel,  XDrawString,
};

use std::ptr;
use std::mem::uninitialized;
use std::mem::transmute;
use std::cmp::{max};
use std::ffi::CString;

use safe_x11::{screen_ratio,get_color};

/// Representation of [`xlib::Window`](../../x11/xlib/type.Window.html)
pub struct XWindow {
    display: *mut xlib::Display,
    // The Application window.
    pub inner: Window,
    fullscreen: bool,
    prev_attribs: XWindowAttributes,
}

fn fixed_with_ratio(x: i32, ratio: f32) -> i32 {
    let fx = x as f32;
    let fixed = fx * ratio;
    fixed as i32
}

fn window_attribs(display: *mut xlib::Display, w: Window) -> XWindowAttributes {
    unsafe {
        let mut attrptr: XWindowAttributes = uninitialized();
        XGetWindowAttributes(display, w, &mut attrptr);
        attrptr
    }
}

impl XWindow {
    /// Generate a reference to the window in certain display. This will return
    /// `None` if the window is the root window.
    pub fn new(d: *mut xlib::Display, w: Window) -> Option<XWindow> {
        if w != 0 {
            let attrs: XWindowAttributes = unsafe { uninitialized() };
            println!("Window created!");
            Some(XWindow {
                display: d,
                inner: w,
                fullscreen: false,
                prev_attribs: attrs,
            })
        } else {
            None
        }
    }

    /// Set the border width To the window.
    pub fn set_border_width(&self, size: u32) {
        unsafe { xlib::XSetWindowBorderWidth(self.display, self.inner, size) };
    }

    /// clients receiving a WM_DELETE_WINDOW message should behave as if
    /// the user selected "delete window" from a hypothetical menu and
    /// also perform any confirmation dialog with the user.
    pub fn delete(&self) {
        // First delete the border window and then the main window.
        let mut ev: XClientMessageEvent = unsafe { uninitialized() };
        ev.type_ = ClientMessage;
        ev.window = self.inner;
        ev.format = 32;
        ev.message_type = 0; // WM_PROTOCOLS
        ev.data = ClientMessageData::new();
        ev.data.set_long(0, 0); // WM_DELETE_WINDOW
        ev.data.set_long(1, CurrentTime as i64);

        let mut event = XEvent::from(ev);

        unsafe { XSendEvent(self.display, self.inner, 0, NoEventMask, &mut event); }
    }

    /// Sets the border color to the selected window
    pub fn set_border_color<T: Into<Vec<u8>>>(&self, color: T) {
        let c = get_color(self.display, color);
        unsafe { XSetWindowBorder(self.display, self.inner, c); }
    }

    /// Raises a window.
    pub fn raise(&self) {
        unsafe {
            xlib::XRaiseWindow(self.display, self.inner);
        }
    }

    /// Register input events on some [`xlib::Window`](../../x11/xlib/type.Window.html)
    ///
    /// # Example
    ///
    /// if we want to handle when a pointer enter into a window rectangle, we
    /// should do something like:
    ///
    /// ```
    /// use x11::xlib;
    ///
    /// let display = open_display("").unwrap();
    /// // Raw window
    /// let window = 0xc00022;
    ///
    /// window.select_input(xlib::EnterWindowMask);
    /// ```
    pub fn select_input(&self, mask: i64) {
        unsafe { xlib::XSelectInput(self.display, self.inner, mask); }
    }

    /// Returns the window attributes from certain window.
    pub fn attributes(&self) -> XWindowAttributes {
        window_attribs(self.display, self.inner)
    }

    /// Moves the window given an offset from where it is.
    pub fn move_offset(&self, xoffset: i32, yoffset: i32) {
        unsafe {
            let mut attributes: XWindowAttributes = uninitialized();
            XGetWindowAttributes(self.display, self.inner, &mut attributes);
            XMoveWindow(self.display, self.inner,
                        attributes.x + xoffset,
                        attributes.y + yoffset);
        }
    }

    /// Moves the window to a particular coord in the screen.
    pub fn move_to(&self, x: i32, y: i32) -> Result<(), &str> {
        let screen = unsafe {
            let s = XDefaultScreenOfDisplay(self.display);
            ptr::read(s)
        };
        
        if 0 > x && x <= screen.width || 0 > y && y <= screen.height {
            Err("Cannot move the window outside the screen!")
        } else {
            unsafe {
                XMoveWindow(self.display, self.inner, x, y);
            };
            Ok(())
        }
    }

    // Some functions for moving within some boundaries.

    /// Move sticky to the left.
    pub fn move_sticky_left(&self, boundaries: &[i32]) {
        let attrs = self.attributes();
        if let Some(v) = boundaries.iter()
                                   .skip_while(|&a| *a >= attrs.x)
                                   .next() {
            let _ = self.move_to(*v, attrs.y);
        }
    }

    /// Move sticky to the right.
    pub fn move_sticky_right(&self, boundaries: &[i32]) {
        let attrs = self.attributes();
        let win_bound = attrs.x + attrs.width;

        if let Some(v) = boundaries.iter()
                                   .skip_while(|&a| *a <= win_bound)
                                   .next() {
            let _ = self.move_to(*v - attrs.width, attrs.y);
        }
    }

    /// Move up sticky.
    pub fn move_sticky_up(&self, boundaries: &[i32]) {
        let attrs = self.attributes();

        if let Some(v) = boundaries.iter()
                                   .skip_while(|&a| *a >= attrs.y)
                                   .next() {
            let _ = self.move_to(attrs.x, *v);
        }
    }

    /// Move down sticky.
    pub fn move_sticky_down(&self, boundaries: &[i32]) {
        let attrs = self.attributes();
        let win_bound = attrs.y + attrs.height;

        if let Some(v) = boundaries.iter()
                                   .skip_while(|&a| *a <= win_bound)
                                   .next() {
            let _ = self.move_to(attrs.x, *v - attrs.height);
        }
    }

    /// Move and resize the window in one step
    pub fn move_resize(&self, x:i32, y: i32, w: u32, h: u32) {
        unsafe {
            XMoveResizeWindow(self.display, self.inner, x, y, w, h as u32);
        }
    }
    
    /// Resizes the window a fixed amount within the height and width.
    pub fn resize(&self, w: i32, h: i32) {
        let ratio = screen_ratio(self.display);
        let attrs = self.attributes();
        unsafe {
            let ww: u32 = max(1, (attrs.width + fixed_with_ratio(w, ratio)) as u32);
            let wh: u32 = max(1, (attrs.height + fixed_with_ratio(h, ratio)) as u32);
            xlib::XResizeWindow(self.display, self.inner,
                                ww, wh as u32);
        }
    }

    /// Resizes the window an absolute amount within the height and width.
    pub fn resize_abs(&self, w: i32, h: i32) {
        let attrs = self.attributes();
        unsafe {
            let ww: u32 = max(1, (attrs.width + w) as u32);
            let wh: u32 = max(1, (attrs.height + h) as u32);
            xlib::XResizeWindow(self.display, self.inner,
                                ww, wh);
        }
    }

    pub fn resize_to(&self, w: i32, h: i32) {
        unsafe {
            let ww: u32 = max(1, w as u32);
            let wh: u32 = max(1, h as u32);
            xlib::XResizeWindow(self.display, self.inner,
                                ww, wh);
        }
    }

    pub fn resize_sticky_left(&self, boundaries: &[i32]) {
        let attrs = self.attributes();

        if let Some(v) = boundaries.iter()
                                   .skip_while(|&a| *a >= attrs.x + attrs.width)
                                   .next() {
            let diff = attrs.width - (*v - attrs.x);
            if *v - attrs.x > 0 {
                let _ = self.resize_to(attrs.width - diff, attrs.height);
            }
       }
    }

    pub fn resize_sticky_right(&self, boundaries: &[i32]) {
        let attrs = self.attributes();
        let win_bound = attrs.x + attrs.width;

        if let Some(v) = boundaries.iter()
                                   .skip_while(|&a| *a <= win_bound)
                                   .next() {
            let new_width = *v - attrs.x;
            let _ = self.resize_to(new_width, attrs.height);
       }
    }

    pub fn resize_sticky_up(&self, boundaries: &[i32]) {
        let attrs = self.attributes();

        if let Some(v) = boundaries.iter()
                                   .skip_while(|&a| *a >= attrs.y + attrs.height)
                                   .next() {
            let diff = attrs.height - (*v - attrs.y);
            if *v - attrs.y > 0 {
                let _ = self.resize_to(attrs.width, attrs.height - diff);
            }
       }
    }

    pub fn resize_sticky_down(&self, boundaries: &[i32]) {
        let attrs = self.attributes();
        let win_bound = attrs.y + attrs.height;

        if let Some(v) = boundaries.iter()
                                   .skip_while(|&a| *a <= win_bound)
                                   .next() {
            let new_height = *v - attrs.y;
            let _ = self.resize_to(attrs.width, new_height);
       }
    }

    /// Raise the focus of the window and set a border.
    pub fn focus(&self) {
        let attrs = self.attributes();
        if attrs.map_state == IsViewable {
            unsafe {
                XSetInputFocus(self.display, self.inner,
                               RevertToParent, CurrentTime)
            };
        }
        self.raise();
        self.set_border_width(1);
        self.set_border_color("red");
    }

    /// Give a black border.
    pub fn unfocus(&self) {
        self.set_border_width(1);
        self.set_border_color("black");
    }

    /// Fullscreen toggle
    pub fn fullscreen(&mut self, wm_state_atom: Atom, fs_atom: Atom) {
        let screen = unsafe { XDefaultScreen(self.display) };
        let dh: u32 = unsafe { XDisplayHeight(self.display, screen) as u32 };
        let dw: u32 = unsafe { XDisplayWidth(self.display, screen) as u32 };

        if !self.fullscreen {
            // First, store the XWindowAttributes to query later.
            self.prev_attribs = self.attributes();

            self.fullscreen = true;
            self.move_resize(0, 0, dw, dh);
            self.set_border_width(0);
        } else {
            self.fullscreen = false;
            self.move_resize(self.prev_attribs.x,
                             self.prev_attribs.y,
                             self.prev_attribs.width as u32,
                             self.prev_attribs.height as u32);
            self.set_border_width(1);
        }

        // EWMH for fullscreen (Don't know how to test it.)
        let fs_atom_slice: &[Atom; 1]  = &[fs_atom];
        let fs_atom_ptr: *const u8 = unsafe { transmute(fs_atom_slice) };

        unsafe {
            XChangeProperty(self.display, self.inner, wm_state_atom,
                            XA_ATOM, 32, PropModeReplace, fs_atom_ptr,
                            self.fullscreen as i32);
        }
    }

    pub fn draw_string<T: Into<Vec<u8>>>(&self, s: T) {
        // Title :D
        println!("Drawing string for {}", self.inner);
        let cstr = CString::new(s).unwrap();
        unsafe {
            let gc = xlib::XCreateGC(self.display, self.inner, 0, ptr::null_mut());
            xlib::XSetForeground(self.display, gc, XWhitePixel(self.display, 0));
            xlib::XSetBackground(self.display, gc, XBlackPixel(self.display, 0));
            println!("Loading fixed");
            let font: xlib::XFontStruct = ptr::read(xlib::XLoadQueryFont(self.display, CString::new("fixed").unwrap().as_ptr()));
            xlib::XSetFont(self.display, gc, font.fid);
            xlib::XClearWindow(self.display, self.inner);
            XDrawString(self.display, self.inner, gc,
                        3, 10, cstr.as_ptr(), cstr.to_bytes().len() as i32);
        }
    }

    pub fn map(&self) {
        unsafe { XMapWindow(self.display, self.inner); }
    }

    pub fn unmap(&self) {
        unsafe { XUnmapWindow(self.display, self.inner); }
    }
}

pub fn change_window_attributes(display: *mut xlib::Display, win: Window, mask: u64,
                                window_attribs: *mut XSetWindowAttributes) {
    unsafe {
        XChangeWindowAttributes(display, win, mask, window_attribs);
    }
}