package world

import (
	"image"
	"image/color"
	"testing"

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

type bgOffsetTheme struct {
	img       image.Image
	scaleMode BackgroundScaleMode
}

func (t bgOffsetTheme) ID() string   { return "bgscale" }
func (t bgOffsetTheme) Name() string { return "bgscale" }

func (t bgOffsetTheme) BackgroundColor() color.Color { return color.RGBA{A: 255} }
func (t bgOffsetTheme) BackgroundImage() image.Image { return t.img }

func (t bgOffsetTheme) BackgroundTileMode() BackgroundTileMode     { return BackgroundTileNone }
func (t bgOffsetTheme) BackgroundScaleMode() BackgroundScaleMode   { return t.scaleMode }
func (t bgOffsetTheme) BackgroundAnchorMode() BackgroundAnchorMode { return BackgroundAnchorViewport }

func (t bgOffsetTheme) PointStyle() Style {
	return Style{FillColor: color.RGBA{A: 255}, PointRadiusPx: 2}
}
func (t bgOffsetTheme) LineStyle() Style {
	return Style{StrokeColor: color.RGBA{A: 255}, StrokeWidthPx: 1}
}
func (t bgOffsetTheme) CircleStyle() Style {
	return Style{FillColor: color.RGBA{A: 255}, StrokeColor: color.RGBA{A: 255}, StrokeWidthPx: 1}
}

func (t bgOffsetTheme) PointClassOverride(PointClassID) (StyleOverride, bool) {
	return StyleOverride{}, false
}
func (t bgOffsetTheme) LineClassOverride(LineClassID) (StyleOverride, bool) {
	return StyleOverride{}, false
}
func (t bgOffsetTheme) CircleClassOverride(CircleClassID) (StyleOverride, bool) {
	return StyleOverride{}, false
}

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

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

	img := image.NewRGBA(image.Rect(0, 0, 4, 4))
	w.SetTheme(bgOffsetTheme{img: img, scaleMode: BackgroundScaleNone})

	params := RenderParams{
		ViewportWidthPx:  10,
		ViewportHeightPx: 10,
		MarginXPx:        2,
		MarginYPx:        2,
		CameraXWorldFp:   5 * SCALE,
		CameraYWorldFp:   5 * SCALE,
		CameraZoom:       1.0,
	}

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

	require.NotEmpty(t, d.CommandsByName("DrawImage"))
	require.Empty(t, d.CommandsByName("DrawImageScaled"))
}

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

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

	img := image.NewRGBA(image.Rect(0, 0, 4, 4))
	w.SetTheme(bgOffsetTheme{img: img, scaleMode: BackgroundScaleFit})

	params := RenderParams{
		ViewportWidthPx:  10,
		ViewportHeightPx: 10,
		MarginXPx:        2,
		MarginYPx:        2,
		CameraXWorldFp:   5 * SCALE,
		CameraYWorldFp:   5 * SCALE,
		CameraZoom:       1.0,
	}

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

	require.NotEmpty(t, d.CommandsByName("DrawImageScaled"))
}