// +build darwin linux

package main

import (
	"image/color"
	"log"

	"gioui.org/app"
	"gioui.org/layout"
	"gioui.org/text"
	"gioui.org/text/shape"
	"gioui.org/unit"

	"golang.org/x/image/font/gofont/goregular"
	"golang.org/x/image/font/sfnt"
)

var (
	face  text.Face
	white = color.RGBA{A: 0xff, R: 0xff, G: 0xff, B: 0xff}
	gray  = color.RGBA{A: 0xff, R: 0xb0, G: 0xb0, B: 0xb0}
	black = color.RGBA{A: 0xff, R: 0x00, G: 0x00, B: 0x00}

	labchan chan string
)

func main() {
	labchan = make(chan string)
	log.Print("Staring event loop")
	go eventloop()
	app.Main()
	log.Print("App closed")
}

func diffInsets(x, y app.Insets) bool {
	return x.Top != y.Top ||
		x.Bottom != y.Bottom ||
		x.Left != y.Left ||
		x.Right != y.Right
}

func eventloop() {
	w := app.NewWindow(
		app.WithWidth(unit.Dp(400)),
		app.WithHeight(unit.Dp(400)),
		app.WithTitle("Hello"))
	gtx := &layout.Context{Queue: w.Queue()}
	var faces shape.Faces

	regular, err := sfnt.Parse(goregular.TTF)
	if err != nil {
		log.Fatal("Cannot parse font.")
	}
	face = faces.For(regular, unit.Sp(16))

	sysinset := &layout.Inset{}
	margin := layout.UniformInset(unit.Dp(10))
	labels := []*text.Label{}
	list := &layout.List{Axis: layout.Vertical}

	resetSysinset := func(x app.Insets) {
		sysinset.Top = x.Top
		sysinset.Bottom = x.Bottom
		sysinset.Left = x.Left
		sysinset.Right = x.Right
	}

	for {
		select {
		case x := <-labchan:
			labels = append(labels, &text.Label{Face: face, Text: x})
		case e := <-w.Events():
			switch e := e.(type) {
			case app.DestroyEvent:
				return
			case app.UpdateEvent:
				gtx.Reset(&e.Config, e.Size)
				faces.Reset(&e.Config)
				resetSysinset(e.Insets)
				sysinset.Layout(gtx, func() {
					margin.Layout(gtx, func() {
						for i := 0; i < len(labels); i++ {
							list.Layout(gtx, len(labels), func(i int) {
								labels[i].Layout(gtx)
							})
						}
					})
				})
				w.Update(gtx.Ops)
			}
		}
	}
}