package gel

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

	"github.com/p9c/p9/pkg/gel/fonts/p9fonts"
	"github.com/p9c/p9/pkg/opts/binary"
	"github.com/p9c/p9/pkg/opts/meta"
	"github.com/p9c/p9/pkg/qu"

	l "github.com/p9c/p9/pkg/gel/gio/layout"
	"github.com/p9c/p9/pkg/gel/gio/op"
)

// testWindow creates a Window suitable for testing without actual GUI.
func testWindow(t *testing.T) *Window {
	t.Helper()
	quit := qu.T()
	th := NewTheme(
		binary.New(meta.Data{}, false, nil),
		p9fonts.Collection(),
		quit,
	)
	w := &Window{
		Theme: th,
		scale: &scaledConfig{1},
	}
	th.WidgetPool = w.NewPool()
	return w
}

// testContext creates a layout.Context for testing with the given size.
func testContext(t *testing.T, size image.Point) l.Context {
	t.Helper()
	ops := new(op.Ops)
	return l.Context{
		Ops: ops,
		Constraints: l.Constraints{
			Min: image.Point{},
			Max: size,
		},
	}
}

// assertDimensionsNonZero checks that dimensions have non-zero width and height.
func assertDimensionsNonZero(t *testing.T, dims l.Dimensions, msg string) {
	t.Helper()
	if dims.Size.X == 0 && dims.Size.Y == 0 {
		t.Errorf("%s: got zero dimensions", msg)
	}
}

// assertDimensionsWithin checks dimensions are within expected bounds.
func assertDimensionsWithin(t *testing.T, dims l.Dimensions, maxX, maxY int, msg string) {
	t.Helper()
	if dims.Size.X > maxX {
		t.Errorf("%s: width %d exceeds max %d", msg, dims.Size.X, maxX)
	}
	if dims.Size.Y > maxY {
		t.Errorf("%s: height %d exceeds max %d", msg, dims.Size.Y, maxY)
	}
}

// assertColorEqual checks two colors are equal.
func assertColorEqual(t *testing.T, got, want color.NRGBA, msg string) {
	t.Helper()
	if got != want {
		t.Errorf("%s: got color %v, want %v", msg, got, want)
	}
}

// assertNoError fails the test if err is not nil.
func assertNoError(t *testing.T, err error, msg string) {
	t.Helper()
	if err != nil {
		t.Errorf("%s: unexpected error: %v", msg, err)
	}
}