#include <xcb/xcb.h>
#include "dat.h"
#include "fn.h"

static xcb_connection_t *conn;
static xcb_screen_t *scr;
static xcb_window_t win;
static xcb_gcontext_t gc;
static xcb_pixmap_t pix;
static u32int *img;
static int depth;

static xcb_screen_t*
getscr(xcb_connection_t *c, int n)
{
	xcb_screen_iterator_t i;

	for(i = xcb_setup_roots_iterator(xcb_get_setup(c)); i.rem; xcb_screen_next(&i))
		if(n-- == 0)
			return i.data;
	return nil;
}

static xcb_visualtype_t*
getvisual(xcb_screen_t *s)
{
	xcb_depth_iterator_t di;
	xcb_visualtype_iterator_t vi;

	for(di = xcb_screen_allowed_depths_iterator(s); di.rem;
	    xcb_depth_next(&di)){
		if(di.data->depth != s->root_depth)
			continue;
		for(vi = xcb_depth_visuals_iterator(di.data); vi.rem;
		    xcb_visualtype_next(&vi))
			if(vi.data->visual_id == s->root_visual)
				return vi.data;
	}
	return nil;
}

static int
validformat(xcb_connection_t *c, xcb_screen_t *s)
{
	const xcb_setup_t *setup;
	xcb_format_iterator_t fi;
	xcb_visualtype_t *v;
	u32int one;
	int lsb;

	setup = xcb_get_setup(c);
	v = getvisual(s);
	if(setup == nil || v == nil || s->root_depth != 24 ||
	   v->_class != XCB_VISUAL_CLASS_TRUE_COLOR ||
	   v->bits_per_rgb_value != 8 ||
	   v->red_mask != 0xff0000 || v->green_mask != 0x00ff00 ||
	   v->blue_mask != 0x0000ff)
		return 0;
	one = 1;
	lsb = *(uchar*)&one != 0;
	if((lsb && setup->image_byte_order != XCB_IMAGE_ORDER_LSB_FIRST) ||
	   (!lsb && setup->image_byte_order != XCB_IMAGE_ORDER_MSB_FIRST))
		return 0;
	for(fi = xcb_setup_pixmap_formats_iterator(setup); fi.rem;
	    xcb_format_next(&fi))
		if(fi.data->depth == 24 && fi.data->bits_per_pixel == 32 &&
		   fi.data->scanline_pad == 32)
			return 1;
	return 0;
}

static void
wincleanup(void)
{
	free(img);
	img = nil;
	if(conn != nil){
		xcb_disconnect(conn);
		conn = nil;
	}
	scr = nil;
	win = 0;
	gc = 0;
	pix = 0;
}

static int
wininit(void)
{
	int n;
	u32int mask, vals[4];
	xcb_intern_atom_cookie_t c1, c2;
	xcb_intern_atom_reply_t *r1, *r2;

	conn = xcb_connect(nil, &n);
	if(conn == nil || xcb_connection_has_error(conn)){
		fprint(2, "strans: popup disabled: cannot connect to X display\n");
		wincleanup();
		return 0;
	}
	scr = getscr(conn, n);
	if(scr == nil || !validformat(conn, scr)){
		fprint(2, "strans: popup disabled: unsupported X root format\n");
		wincleanup();
		return 0;
	}
	depth = scr->root_depth;
	win = xcb_generate_id(conn);
	mask = XCB_CW_BACK_PIXEL | XCB_CW_BORDER_PIXEL |
	       XCB_CW_OVERRIDE_REDIRECT | XCB_CW_SAVE_UNDER;
	vals[0] = Colbg;
	vals[1] = 0;
	vals[2] = 1;
	vals[3] = 1;
	xcb_create_window(conn, XCB_COPY_FROM_PARENT, win, scr->root,
		0, 0, 1, 1, 0, XCB_WINDOW_CLASS_INPUT_OUTPUT,
		scr->root_visual, mask, vals);
	c1 = xcb_intern_atom(conn, 0,
		strlen("_NET_WM_WINDOW_TYPE"), "_NET_WM_WINDOW_TYPE");
	c2 = xcb_intern_atom(conn, 0,
		strlen("_NET_WM_WINDOW_TYPE_TOOLTIP"),
		"_NET_WM_WINDOW_TYPE_TOOLTIP");
	r1 = xcb_intern_atom_reply(conn, c1, nil);
	r2 = xcb_intern_atom_reply(conn, c2, nil);
	if(r1 != nil && r2 != nil)
		xcb_change_property(conn, XCB_PROP_MODE_REPLACE,
			win, r1->atom, XCB_ATOM_ATOM, 32, 1, &r2->atom);
	free(r1);
	free(r2);
	gc = xcb_generate_id(conn);
	xcb_create_gc(conn, gc, win, 0, nil);
	pix = xcb_generate_id(conn);
	xcb_create_pixmap(conn, depth, pix, win, Imgw, Imgh);
	mask = XCB_CW_BACK_PIXMAP;
	xcb_change_window_attributes(conn, win, mask, &pix);
	img = emalloc(Imgw * Imgh * sizeof(img[0]));
	if(!textinit()){
		fprint(2, "strans: popup disabled: no usable fonts\n");
		wincleanup();
		return 0;
	}
	return 1;
}

static void
putimage(int w, int h)
{
	if(w <= 0 || w > Imgw || h <= 0 || h > Imgh)
		return;
	xcb_put_image(conn, XCB_IMAGE_FORMAT_Z_PIXMAP, pix, gc,
		w, h, 0, 0, 0, depth, w * h * 4, (u8int*)img);
	/* The retained background pixmap lets the server repaint exposures. */
	xcb_clear_area(conn, 0, win, 0, 0, w, h);
}

static int
winhide(void)
{
	xcb_unmap_window(conn, win);
	return xcb_flush(conn) > 0;
}

static int
winshow(Drawcmd *dc)
{
	Popup p;
	int px, py;
	u32int vals[4];
	xcb_query_pointer_reply_t *ptr;
	xcb_query_pointer_cookie_t cookie;

	if(dc->nkouho <= 0 && dc->pre.n == 0){
		return winhide();
	}
	popuplayout(dc, scr->width_in_pixels, &p);
	if(p.w <= 0 || p.w > Imgw || p.h <= 0 || p.h > Imgh)
		return 0;
	vals[2] = p.w;
	vals[3] = p.h;
	px = py = 0;
	if(!dc->caret.valid){
		cookie = xcb_query_pointer(conn, scr->root);
		ptr = xcb_query_pointer_reply(conn, cookie, nil);
		if(ptr == nil)
			return 0;
		px = ptr->root_x;
		py = ptr->root_y;
		free(ptr);
	}
	popupposition(&dc->caret, px, py, scr->width_in_pixels,
		scr->height_in_pixels, p.w, p.h, &px, &py);
	vals[1] = py;
	vals[0] = px;
	xcb_configure_window(conn, win,
		XCB_CONFIG_WINDOW_X | XCB_CONFIG_WINDOW_Y |
		XCB_CONFIG_WINDOW_WIDTH | XCB_CONFIG_WINDOW_HEIGHT,
		vals);
	xcb_map_window(conn, win);
	popupdraw(img, dc, &p);
	putimage(p.w, p.h);
	return xcb_flush(conn) > 0;
}

void
drawthread(void*)
{
	Drawcmd dc;

	threadsetname("draw");
	if(!wininit())
		return;
	while(chanrecv(drawc, &dc) > 0){
		while(channbrecv(drawc, &dc) > 0)
			;
		if(dc.nkouho == 0 && dc.pre.n == 0){
			if(!winhide())
				break;
		}else if(!winshow(&dc))
			break;
	}
	wincleanup();
}