// +build darwin linux

package main

import (
	"fmt"
	"image/color"
	"log"
	"time"

	gio "git.wow.st/gmp/giowrap"

	"gioui.org/ui"
	"gioui.org/ui/app"
	"gioui.org/ui/layout"
	"gioui.org/ui/text"

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

var (
	sel  int32
	face text.Face
)

func main() {
	log.Print("Staring event loop")
	go eventloop()
	app.Main()
	log.Print("App closed")
}

func NewButton(t string, lops ...gio.LabelOption) gio.Clickable {
	lops = append([]gio.LabelOption{gio.Face(face), gio.Align(text.Middle)}, lops...)
	lbl := gio.NewLabel(t, lops...)
	bg := gio.NewBackground(
		gio.Color(color.RGBA{A: 0xff, R: 0xf0, G: 0xf0, B: 0xe0}),
		gio.Radius(ui.Dp(4)))
	return gio.AsClickable(bg(lbl))
}

type SLabel struct {
	w      gio.Clickable
	bg     *gio.Background
	active *bool
}

func NewSLabel(t string, active *bool, lops ...gio.LabelOption) *SLabel {
	ret := &SLabel{}
	lops = append([]gio.LabelOption{gio.Face(face)}, lops...)
	lbl := gio.NewLabel(t, lops...)
	bg := &gio.Background{
		Color:  color.RGBA{A: 0xff, R: 0xf0, G: 0xf0, B: 0xe0},
		Radius: ui.Dp(4),
		Inset:  layout.UniformInset(ui.Dp(4)),
	}
	if *active {
		bg.Color = color.RGBA{A: 0xff, R: 0xf0, G: 0xf0, B: 0xe0}
	}
	l := gio.AsClickable(gio.Enclose(bg, lbl))
	ret.w = l
	ret.bg = bg
	ret.active = active
	return ret
}

func (w *SLabel) Layout(ctx *gio.Context) {
	if *w.active {
		w.bg.Color = color.RGBA{A: 0xff, R: 0xe0, G: 0xe0, B: 0xe0}
	} else {
		w.bg.Color = color.RGBA{A: 0xff, R: 0xf0, G: 0xf0, B: 0xe0}
	}
	w.w.Layout(ctx)
	if w.w.Clicked(ctx) {
		if *w.active {
			*w.active = false
		} else {
			*w.active = true
		}
	}
}

func NewCal(sm *SelectableMonth) gio.Widget {
	pad := gio.NewLabel("", gio.Face(face), gio.Align(text.End))
	ds := make([]gio.Widget, 42)
	for i := 0; i < len(ds); i++ {
		if i < sm.Pad || i >= sm.DaysIn+sm.Pad {
			ds[i] = pad
		} else {
			ds[i] = NewSLabel(fmt.Sprintf("%d", i+1-sm.Pad), &sm.S[i+1-sm.Pad], gio.Align(text.End))
		}
	}
	return gio.NewGrid(7)(ds...)
}

func eventloop() {
	w := app.NewWindow(
		app.WithWidth(ui.Dp(600)),
		app.WithHeight(ui.Dp(600)),
		app.WithTitle("Calendar"))
	ctx := gio.NewContext(w)
	sm := NewMonth(time.Now())

	regular, err := sfnt.Parse(goregular.TTF)
	face = ctx.Faces.For(regular, ui.Sp(20))
	if err != nil {
		log.Fatal("Cannot parse font.")
	}

	bg := gio.NewBackground(
		gio.Color(color.RGBA{A: 0xff, R: 0xf0, G: 0xf0, B: 0xe0}))

	margin := gio.NewInset(gio.Size(ui.Dp(10)))
	f1 := gio.NewFlex(gio.Axis(layout.Vertical))
	f2 := gio.NewFlex(gio.Axis(layout.Horizontal))
	sidegrid := gio.NewGrid(1)
	yrs := make([]gio.Widget, 6)
	curyr := sm.Year

	topgrid := gio.NewGrid(3)
	lbtn := NewButton("   <   ")
	mth := gio.NewLabel("", gio.Face(face), gio.Align(text.Middle))
	rbtn := NewButton("   >   ")

	var cal gio.Widget

	f3 := gio.NewFlex(gio.Axis(layout.Vertical))
	daygrid := gio.NewGrid(7)
	sun := NewSLabel("Sun", &sm.Ws[time.Sunday], gio.Align(text.End))
	mon := NewSLabel("Mon", &sm.Ws[time.Monday], gio.Align(text.End))
	tue := NewSLabel("Tue", &sm.Ws[time.Tuesday], gio.Align(text.End))
	wed := NewSLabel("Wed", &sm.Ws[time.Wednesday], gio.Align(text.End))
	thu := NewSLabel("Thu", &sm.Ws[time.Thursday], gio.Align(text.End))
	fri := NewSLabel("Fri", &sm.Ws[time.Friday], gio.Align(text.End))
	sat := NewSLabel("Sat", &sm.Ws[time.Saturday], gio.Align(text.End))

	resetCal := func() {
		cal = NewCal(sm)
		for i, _ := range yrs {
			yrs[i] = NewButton(fmt.Sprintf("%d", curyr-i),
				gio.Align(text.Start))
		}
		w.Invalidate()
	}
	resetCal()

	for {
		select {
		case e := <-w.Events():
			switch e := e.(type) {
			case app.DestroyEvent:
				return
			case app.UpdateEvent:
				ctx.Reset(e)

				mth.SetText(fmt.Sprintf("%s %d", sm.Month.String(), sm.Year))

				ows := sm.Ws
				bg(margin(f1(
					topgrid(lbtn, mth, rbtn),
					f2(
						sidegrid(yrs...),
						f3(
							daygrid(sun, mon, tue, wed, thu, fri, sat),
							cal,
						),
					),
				))).Layout(ctx)
				ctx.Update()

				for i := time.Sunday; i < 7; i++ {
					switch {
					case sm.Ws[i] && !ows[i]:
						sm.SelectWeekday(i)
						resetCal()
					case !sm.Ws[i] && ows[i]:
						sm.DeselectWeekday(i)
						resetCal()
					}
				}
				if lbtn.Clicked(ctx) {
					sm.Previous()
					resetCal()
				}
				if rbtn.Clicked(ctx) {
					sm.Next()
					resetCal()
				}
				for i, y := range yrs {
					if y.(gio.Clickable).Clicked(ctx) {
						sm.Year = curyr - i
						sm.Refresh()
						resetCal()
					}
				}
				sm.CheckSel()
			}
		}
	}
}