package main

import (
	"testing"

	"git.piksar.eu/piotr/groundstation/internal/display"
)

type recordingCanvas struct {
	width, height   int
	lines           []string
	clears, flushes int
}

func (c *recordingCanvas) Size() (int, int) { return c.width, c.height }
func (c *recordingCanvas) Clear()           { c.clears++ }
func (c *recordingCanvas) Text(_, _ int, message string) {
	c.lines = append(c.lines, message)
}
func (c *recordingCanvas) Flush() { c.flushes++ }

func TestBuildTargetWiresSharedVideoPresenceToFallback(t *testing.T) {
	opener, template, err := buildTarget("x11")
	if err != nil {
		t.Fatal(err)
	}

	x11, ok := opener.(display.X11Opener)
	if !ok {
		t.Fatalf("opener %T must be the X11 target", opener)
	}
	if x11.Video == nil {
		t.Fatal("x11 opener must observe the video presence signal")
	}

	canvas := &recordingCanvas{width: 800, height: 600}
	template.Draw(canvas)
	if len(canvas.lines) != 1 || canvas.lines[0] != "Brak połączenia WFB" {
		t.Fatalf("lines=%q want the exact fallback text", canvas.lines)
	}

	// The opener and the template must share one presence signal so the
	// video lifecycle observed by the session drives the fallback.
	x11.Video.SetActive(true)
	canvas.lines = nil
	template.Draw(canvas)
	if len(canvas.lines) != 0 {
		t.Fatalf("lines=%q must disappear while video is present", canvas.lines)
	}

	x11.Video.SetActive(false)
	canvas.lines = nil
	template.Draw(canvas)
	if len(canvas.lines) != 1 || canvas.lines[0] != "Brak połączenia WFB" {
		t.Fatalf("lines=%q want the fallback back after video end", canvas.lines)
	}
}

func TestBuildTargetRejectsUnknownTarget(t *testing.T) {
	if _, _, err := buildTarget("hdmi-mirror"); err == nil {
		t.Fatal("unknown target must fail")
	}
}