package display

import "testing"

func TestOSDTemplateStaysTransparentWhileVideoAbsent(t *testing.T) {
	canvas := &fakeCanvas{width: 800, height: 600}

	NewOSDTemplate(NewVideoPresence()).Draw(canvas)

	clears, flushes := canvas.drawCounts()
	if clears != 1 || flushes != 1 {
		t.Fatalf("clears=%d flushes=%d want 1 and 1", clears, flushes)
	}
	if lines := canvas.lines(); len(lines) != 0 {
		t.Fatalf("OSD lines=%q want none: the OSD is a telemetry surface, not a fallback", lines)
	}
}

func TestOSDTemplateStaysTransparentWhileVideoPresent(t *testing.T) {
	canvas := &fakeCanvas{width: 800, height: 600}
	presence := NewVideoPresence()
	presence.SetActive(true)

	NewOSDTemplate(presence).Draw(canvas)

	if lines := canvas.lines(); len(lines) != 0 {
		t.Fatalf("OSD lines=%q want none while video is present", lines)
	}
}

func TestOSDTemplateNeverDrawsTheFallbackText(t *testing.T) {
	canvas := &fakeCanvas{width: 800, height: 600}
	presence := NewVideoPresence()
	template := NewOSDTemplate(presence)

	for _, active := range []bool{false, true, false} {
		presence.SetActive(active)
		template.Draw(canvas)
		if lines := canvas.lines(); len(lines) != 0 {
			t.Fatalf("lines=%q after presence=%v want none", lines, active)
		}
	}
}