package main

import (
	"image"
	"image/color"

	"gioui.org/f32"
	"gioui.org/gesture"
	"gioui.org/io/pointer"
	"gioui.org/layout"
	"gioui.org/op/clip"
	"gioui.org/op/paint"
	"gioui.org/text"
	"gioui.org/unit"
	"gioui.org/widget/material"
)

var (
	black    = color.RGBA{A: 0xff, R: 0, G: 0, B: 0}
	white    = color.RGBA{A: 0xff, R: 0xff, G: 0xff, B: 0xff}
	gray     = color.RGBA{A: 0xff, R: 0xf0, G: 0xf0, B: 0xf0}
	darkgray = color.RGBA{A: 0xff, R: 0xa0, G: 0xa0, B: 0xa0}
)

type Overlay struct {
	Size       unit.Value
	Text       string
	Click      gesture.Click
	Color      color.RGBA
	Background color.RGBA
	Alignment  text.Alignment
}

func (b *Overlay) Layout(gtx C) D {
	ins := layout.UniformInset(unit.Dp(1))
	return ins.Layout(gtx, func(gtx C) D {
		st := layout.Stack{}
		c2 := layout.Stacked(func(gtx C) D {
			l := material.Label(th, b.Size, b.Text)
			ins := layout.UniformInset(unit.Dp(4))
			l.Color = b.Color
			ret := ins.Layout(gtx, func(gtx C) D {
				return l.Layout(gtx)
			})
			pointer.Rect(image.Rect(0, 0, ret.Size.X, ret.Size.Y)).Add(gtx.Ops)
			return ret
		})
		c1 := layout.Expanded(func(gtx C) D {
			return layoutRRect(b.Background, gtx)
		})
		return st.Layout(gtx, c1, c2)
	})
}

type SelButton struct {
	Button
	SelColor color.RGBA
	Selected bool
}

type Button struct {
	Size       unit.Value
	Label      string
	Click      gesture.Click
	Color      color.RGBA
	Background color.RGBA
	Alignment  text.Alignment
	clicked    bool
}

func layoutRRect(col color.RGBA, gtx C) D {
	r := float32(gtx.Px(unit.Dp(4)))
	sz := image.Point{X: gtx.Constraints.Min.X, Y: gtx.Constraints.Min.Y}
	w, h := float32(sz.X), float32(sz.Y)
	rect := f32.Rectangle{
			f32.Point{0, 0},
			f32.Point{w, h},
		}
	//clip.RoundRect(gtx.Ops, rect, r, r, r, r)
	clip.RRect{Rect: rect, NE: r, NW: r, SE: r, SW: r}.Add(gtx.Ops)
	paint.ColorOp{Color: col}.Add(gtx.Ops)
	paint.PaintOp{Rect: f32.Rectangle{Max: f32.Point{X: w, Y: h}}}.Add(gtx.Ops)
	return layout.Dimensions{Size: sz}
}

func (b *Button) Layout(gtx C) D {
	mwidth := gtx.Constraints.Min.X
	b.clicked = false
	for _, ev := range b.Click.Events(gtx) {
		if ev.Type == gesture.TypeClick {
			b.clicked = true
		}
	}
	ins := layout.UniformInset(unit.Dp(1))
	return ins.Layout(gtx, func(gtx C) D {
		st := layout.Stack{}
		c2 := layout.Stacked(func(gtx C) D {
			l := material.Label(th, b.Size, b.Label)
			ins := layout.UniformInset(unit.Dp(4))
			//paint.ColorOp{Color: b.Color}.Add(ops)
			ret := ins.Layout(gtx, func(gtx C) D {
				return l.Layout(gtx)
			})
			pointer.Rect(image.Rect(0, 0, ret.Size.X, ret.Size.Y)).Add(gtx.Ops)
			b.Click.Add(gtx.Ops)
			return ret
		})
		c1 := layout.Expanded(func(gtx C) D {
			gtx.Constraints.Min.X = mwidth
			return layoutRRect(b.Background, gtx)
		})
		return st.Layout(gtx, c1, c2)
	})
}

func (b *Button) Clicked() bool {
	return b.clicked
}

func (b *SelButton) Toggle() {
	b.Selected = !b.Selected
	b.SelColor, b.Background = b.Background, b.SelColor
}

func (b *SelButton) Select() {
	if !b.Selected {
		b.Toggle()
	}
}

func (b *SelButton) Deselect() {
	if b.Selected {
		b.Toggle()
	}
}

func (b *SelButton) Clicked() bool {
	if b.clicked {
		b.Toggle()
		return true
	} else {
		return false
	}
}