package world

import (
	"image/color"
	"testing"

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

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

	base := Style{
		FillColor:        color.RGBA{R: 1, A: 255},
		StrokeColor:      color.RGBA{G: 2, A: 255},
		StrokeWidthPx:    1.0,
		StrokeDashes:     []float64{3, 1},
		StrokeDashOffset: 0.5,
		PointRadiusPx:    2.0,
	}

	newWidth := 5.0
	newRadius := 7.0

	override := StyleOverride{
		StrokeWidthPx: &newWidth,
		PointRadiusPx: &newRadius,
		// Everything else is unset (nil) => must remain from base.
	}

	out := override.Apply(base)

	require.Equal(t, base.FillColor, out.FillColor)
	require.Equal(t, base.StrokeColor, out.StrokeColor)
	require.Equal(t, 5.0, out.StrokeWidthPx)
	require.Equal(t, base.StrokeDashes, out.StrokeDashes)
	require.Equal(t, base.StrokeDashOffset, out.StrokeDashOffset)
	require.Equal(t, 7.0, out.PointRadiusPx)
}

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

	tbl := NewStyleTable()

	_, ok := tbl.Get(StyleIDDefaultLine)
	require.True(t, ok)

	_, ok = tbl.Get(StyleIDDefaultCircle)
	require.True(t, ok)

	_, ok = tbl.Get(StyleIDDefaultPoint)
	require.True(t, ok)
}

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

	tbl := NewStyleTable()

	dashes := []float64{10, 5}
	override := StyleOverride{
		StrokeDashes: &dashes,
	}
	id := tbl.AddDerived(StyleIDDefaultLine, override)

	got, ok := tbl.Get(id)
	require.True(t, ok)
	require.Equal(t, []float64{10, 5}, got.StrokeDashes)

	// Mutate caller slice; table must not change.
	dashes[0] = 999

	got2, ok := tbl.Get(id)
	require.True(t, ok)
	require.Equal(t, []float64{10, 5}, got2.StrokeDashes)

	// Mutate returned slice; table must not change.
	got2.StrokeDashes[0] = 123

	got3, ok := tbl.Get(id)
	require.True(t, ok)
	require.Equal(t, []float64{10, 5}, got3.StrokeDashes)
}

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

	require.Equal(t, 100, DefaultPriorityLine)
	require.Equal(t, 200, DefaultPriorityCircle)
	require.Equal(t, 300, DefaultPriorityPoint)

	require.Less(t, DefaultPriorityLine, DefaultPriorityCircle)
	require.Less(t, DefaultPriorityCircle, DefaultPriorityPoint)
}