package world

import (
	"image/color"
	"testing"

	"github.com/stretchr/testify/require"
)

func TestRender_CircleRadiusScale_AffectsRenderedRadiusPx(t *testing.T) {
	t.Parallel()

	w := NewWorld(10, 10)
	w.resetGrid(2 * SCALE)

	// Ensure index state is initialized so Add triggers rebuild if needed.
	w.IndexOnViewportChange(10, 10, 1.0)

	_, err := w.AddCircle(5, 5, 2) // raw radius = 2 units
	require.NoError(t, err)

	// scale = 2.0
	require.NoError(t, w.SetCircleRadiusScaleFp(2*SCALE))

	// Reindex explicitly (safe).
	w.Reindex()

	params := RenderParams{
		ViewportWidthPx:  10,
		ViewportHeightPx: 10,
		MarginXPx:        0,
		MarginYPx:        0,
		CameraXWorldFp:   5 * SCALE,
		CameraYWorldFp:   5 * SCALE,
		CameraZoom:       1.0,
		Options: &RenderOptions{
			BackgroundColor: color.RGBA{A: 255},
		},
	}

	d := &fakePrimitiveDrawer{}
	require.NoError(t, w.Render(d, params))

	circles := d.CommandsByName("AddCircle")
	require.NotEmpty(t, circles)

	// AddCircle args: cx, cy, rPx
	rPx := circles[0].Args[2]
	require.Equal(t, float64(4), rPx, "raw radius=2 with scale=2 => eff radius=4 => rPx=4 at zoom=1")
}