package x // import "hhvn.uk/hbspbar/x"

import (
	"os"
	"image"

	"hhvn.uk/hbspbar/config"
	"hhvn.uk/hbspbar/common"

	"github.com/jezek/xgb"
	"github.com/jezek/xgb/xproto"
	"github.com/jezek/xgbutil"
	"github.com/jezek/xgbutil/xgraphics"
	"github.com/BurntSushi/freetype-go/freetype/truetype"
)

var InitErr error
var X       *xgb.Conn
var XU      *xgbutil.XUtil
var Screen  *xproto.ScreenInfo

var font    *truetype.Font
var tw, th  int
var tbpad   int

func init() {
	var err error

	X, err = xgb.NewConn()
	if err != nil {
		InitErr = err
		return
	}

	XU, err = xgbutil.NewConnXgb(X)
	if err != nil {
		InitErr = err
		return
	}

	setup := xproto.Setup(X)
	Screen = setup.DefaultScreen(X)

	read, err := os.Open(config.Font)
	if err != nil {
		InitErr = common.Perror("os.Open", err)
		return
	}

	font, err = xgraphics.ParseFont(read)
	if err != nil {
		InitErr = common.Perror("xgraphics.ParseFont", err)
		return
	}

	test := xgraphics.New(XU, image.Rect(0, 0, int(config.FontSize * 10), int(config.FontSize * 10)))
	tw, th, _ = test.Text(0, 0, int2BGRA(config.Fg), config.FontSize, font, "X")
	tbpad = (int(config.H) - th) / 2
}

func int2BGRA(argb uint32) (xgraphics.BGRA) {
	return xgraphics.BGRA{
		B: uint8( argb & 0x000000ff),
		G: uint8((argb & 0x0000ff00) >> 8),
		R: uint8((argb & 0x00ff0000) >> 16),
		A: uint8((argb & 0xff000000) >> 24) }
}

func GraphicReInit(i **xgraphics.Image, r image.Rectangle) {
	if *i != nil {
		(*i).Destroy()
	}

	*i = xgraphics.New(XU, r)
}

func DrawText(i *xgraphics.Image, x int, col uint32, text string) (int, error) {
	nx, _, err := i.Text(x, config.FontYPad,
		int2BGRA(col), config.FontSize, font, text)
	return nx - x, err
}

func TextWidth(text string) (int) {
	return tw * len(text)
}

func DrawRect(i *xgraphics.Image, x, y, w, h int, c uint32, fill bool) {
	col := int2BGRA(c)

	var ix, iy int

	for ix = x; ix < x + w; ix++ {
		for iy = y; iy < y + h; iy++ {
			if fill || ix == x || ix == x + w - 1 ||
					iy == y || iy == y + h - 1 {
				i.Set(ix, iy, col)
			}
		}
	}
}