use crate::xtypes::*;
use crate::xcolor::DisplayColorExt;

use std::sync::Arc;

use xcb::{ Xid };
use xcb::x::{
  self,
  ClientMessageData,
  Cw, CreateWindow,
  EventMask,
  Screen,
  WindowClass
};

mod xcolor;
mod xtypes;


#[derive(Clone, Copy, PartialEq, Eq)]
enum ScreenSide { Top, Bottom, Left, Right }

struct DockConfiguration {
  thickness: u16,
  side: ScreenSide,
  background_pixel: u32,
}

struct Dock {
  configuration: DockConfiguration,
  window: Window,
}

impl HasWindow for Dock {
  fn window(&self) -> &Window { &self.window }
}


#[derive(Debug)]
struct Rectangle<T> {
  left: T,
  top: T,
  width: T,
  height: T,
}



fn main() -> xcb::Result<()> {
  let display = Arc::new(Display::new()?);

  // #d4ffcc
  let background_pixel = display.allocate_color(54484, 65535, 52428)?;

  let _dock = Dock::new(Arc::clone(&display), DockConfiguration {
    thickness: 50,
    side: ScreenSide::Bottom,
    background_pixel,
  })?;

  loop {
    match display.wait_for_event()? {
      xcb::Event::X(x::Event::ButtonPress(event)) => {
        println!("click {:?}", event);
      }

      xcb::Event::X(x::Event::ClientMessage(event)) => {
        if let ClientMessageData::Data32([atom, ..]) = event.data() {
          if atom == display.atoms().wm_delete_window.resource_id() {
            break;
          }
        }
      }

      event => { println!("unknown event {:?}", event); }
    }
  }

  Ok(())
}


impl Dock {
  fn new(display: Arc<Display>, configuration: DockConfiguration)
    -> xcb::Result<Dock>
  {
    let screen = display.screen();

    let dock_bounds = Dock::compute_bounds(&screen, &configuration);

    println!("back pixel {:?}", configuration.background_pixel);
    let window = Window::new(Arc::clone(&display), &mut CreateWindow {
      depth: x::COPY_FROM_PARENT as u8,
      wid: x::Window::none(),
      parent: screen.root(),
      x: dock_bounds.left as i16,
      y: dock_bounds.top as i16,
      width: dock_bounds.width,
      height: dock_bounds.height,
      border_width: 0,
      class: WindowClass::InputOutput,
      visual: screen.root_visual(),
      value_list: &[
        Cw::BackPixel(configuration.background_pixel),
        Cw::EventMask(EventMask::EXPOSURE | EventMask::BUTTON_PRESS),
      ],
    })?;
    let dock = Dock { window, configuration };

    dock.set_string_property(&x::ATOM_WM_NAME, b"grass bar")?;

    dock.set_atom_property(&display.atoms().wm_protocols,
                           &[display.atoms().wm_delete_window])?;

    dock.set_atom_property(&display.atoms().wm_type,
                           &[display.atoms().wm_type_dock])?;

    dock.set_strut_properties(&screen)?;

    dock.map_window()?;

    Ok(dock)
  }


  fn set_strut_properties(&self, screen: &Screen) -> xcb::Result<()> {
    let atoms = self.atoms();

    let thickness = self.configuration.thickness as u32;

    let strut_values = match self.configuration.side {
      ScreenSide::Left => &[thickness, 0 as u32, 0 as u32, 0 as u32],
      ScreenSide::Right => &[0 as u32, thickness, 0 as u32, 0 as u32],
      ScreenSide::Top => &[0 as u32, 0 as u32, thickness, 0 as u32],
      ScreenSide::Bottom => &[0 as u32, 0 as u32, 0 as u32, thickness],
    };
    self.set_cardinal_property(&atoms.wm_strut, strut_values)?;

    let strut_partial_values = &[
      strut_values[0],
      strut_values[1],
      strut_values[2],
      strut_values[3],

      0 as u32,
      if self.configuration.side == ScreenSide::Left {
        screen.height_in_pixels() as u32
      } else { 0 as u32 },

      0 as u32,
      if self.configuration.side == ScreenSide::Right {
        screen.height_in_pixels() as u32
      } else { 0 as u32 },

      0 as u32,
      if self.configuration.side == ScreenSide::Top {
        screen.width_in_pixels() as u32
      } else { 0 as u32 },

      0 as u32,
      if self.configuration.side == ScreenSide::Bottom {
        screen.width_in_pixels() as u32
      } else { 0 as u32 },
    ];

    self.set_cardinal_property(&atoms.wm_strut_partial,
                               strut_partial_values)?;

    Ok(())
  }


  fn compute_bounds(screen: &Screen, configuration: &DockConfiguration)
    -> Rectangle<u16>
  {
    if configuration.side == ScreenSide::Top
       || configuration.side == ScreenSide::Bottom
    {
      let left = 0;
      let width = screen.width_in_pixels();
      let height = configuration.thickness;

      let top = if configuration.side == ScreenSide::Bottom {
        screen.height_in_pixels() - height
      } else { 0 };

      Rectangle { left, top, width, height }
    } else {
      let top = 0;
      let height = screen.height_in_pixels();
      let width = configuration.thickness;

      let left = if configuration.side == ScreenSide::Right {
        screen.width_in_pixels() - width
      } else { 0 };

      Rectangle { left, top, width, height }
    }
  }
}