use crate::window::GraphicsContext;
use buffer::Buffer;
use geometry::HasDimensions;
use raw_window_handle::XlibHandle;
use std::os::raw::{c_char, c_uint};
use x11_dl::xlib::{Display, Visual, Xlib, ZPixmap, GC};

pub struct X11GraphicsContext {
    handle: XlibHandle,
    lib: Xlib,
    gc: GC,
    visual: *mut Visual,
    depth: i32,
}

impl X11GraphicsContext {
    pub unsafe fn new(handle: XlibHandle) -> Self {
        let lib = match Xlib::open() {
            Ok(lib) => lib,
            Err(e) => panic!("{:?}", e),
        };
        let screen = (lib.XDefaultScreen)(handle.display as *mut Display);
        let gc = (lib.XDefaultGC)(handle.display as *mut Display, screen);
        let visual = (lib.XDefaultVisual)(handle.display as *mut Display, screen);
        let depth = (lib.XDefaultDepth)(handle.display as *mut Display, screen);

        Self { handle, lib, gc, visual, depth }
    }
}

impl GraphicsContext for X11GraphicsContext {
    unsafe fn blit(&mut self, buffer: &Buffer) {
        let array = buffer.as_u32_slice();
        let dimensions = buffer.dimensions();
        //create image
        let image = (self.lib.XCreateImage)(
            self.handle.display as *mut Display,
            self.visual,
            self.depth as u32,
            ZPixmap,
            0,
            (array.as_ptr()) as *mut c_char,
            dimensions.width as u32,
            dimensions.height as u32,
            32,
            (dimensions.width * 4) as i32,
        );

        //push image to window
        (self.lib.XPutImage)(
            self.handle.display as *mut Display,
            self.handle.window,
            self.gc,
            image,
            0,
            0,
            0,
            0,
            dimensions.width as c_uint,
            dimensions.height as c_uint,
        );

        (*image).data = std::ptr::null_mut();
        (self.lib.XDestroyImage)(image);
    }
}