package display

// FallbackTemplate is the no-video kiosk layout: a cleared black canvas with
// the fallback lines. While decoded video is present the fallback
// disappears: the canvas stays plain black so the video window keeps
// rendering priority without stale text around or behind it, and the exact
// fallback lines return when video ends.
type FallbackTemplate struct {
	fallback StatusTemplate
	video    *VideoPresence
}

// NewFallbackTemplate builds a template that draws the given fallback lines
// only while the shared presence reports no video.
func NewFallbackTemplate(video *VideoPresence, lines ...string) FallbackTemplate {
	return FallbackTemplate{fallback: NewStatusTemplate(lines...), video: video}
}

func (t FallbackTemplate) Draw(canvas Canvas) {
	canvas.Clear()
	if !t.video.Active() {
		drawLines(canvas, t.fallback.lines)
	}
	canvas.Flush()
}