package webcam

import (
	"image"
	"image/color"
	"time"

	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/canvas"
	"fyne.io/fyne/v2/widget"
	"gocv.io/x/gocv"
)

var _ fyne.WidgetRenderer = (*webcamRenderer)(nil)

type Webcam struct {
	widget.BaseWidget

	WebcamID  int64
	UpdateFPS int64
	fpsTimer  *time.Ticker
}

func NewWebcam() *Webcam {
	w := &Webcam{}
	w.ExtendBaseWidget(w)
	w.WebcamID = 0
	w.UpdateFPS = 25

	return w
}

func (w *Webcam) Resize(s fyne.Size) {
	w.BaseWidget.Resize(s)
}

func (w *Webcam) CreateRenderer() fyne.WidgetRenderer {
	fpsTimer := time.NewTicker(time.Duration(1000/25) * time.Millisecond)
	go func(w *Webcam) {
		for {
			_ = <-fpsTimer.C
			w.Refresh()
		}
	}(w)
	return newWebcamRenderer(w)
}

type webcamRenderer struct {
	webcam           *Webcam
	background       *canvas.Rectangle
	currentframe     *canvas.Raster
	goCVVideoCapture *gocv.VideoCapture
}

func renderframe(w, h int) image.Image {
	frameImage := image.NewRGBA(image.Rect(0, 0, w, h))
	return frameImage
}

func (r *webcamRenderer) actualrenderframe(w, h int) image.Image {
	webcam, _ := gocv.VideoCaptureDevice(int(r.webcam.WebcamID))
	img := gocv.NewMat()
	webcam.Read(&img)
	frameImage, _ := img.ToImage() //no point doing anything other than returning anyway!
	return frameImage
}

func newWebcamRenderer(w *Webcam) *webcamRenderer {
	renderer := &webcamRenderer{
		webcam:     w,
		background: canvas.NewRectangle(color.RGBA{255, 0, 255, 255}),
	}
	renderer.currentframe = canvas.NewRaster(renderer.actualrenderframe)
	return renderer
}

func (r *webcamRenderer) Objects() []fyne.CanvasObject {
	// The order is critical, rect is drawn first then currentframe
	return []fyne.CanvasObject{r.background, r.currentframe}
}

func (r *webcamRenderer) Layout(s fyne.Size) {
	r.background.Resize(s)
	r.currentframe.Resize(s)
}

func (r *webcamRenderer) MinSize() fyne.Size {
	return fyne.NewSize(200, 200)
}

func (r *webcamRenderer) Refresh() {
	r.currentframe.Refresh()
}

func (r *webcamRenderer) Destroy() {
	r.webcam.fpsTimer.Stop()
} // Called when the renderer is destroyed