core/server: add generic dbus service

- Add QML client with subscribe/introspect/getprop/setprop/call
- Add CLI helper `dms notify` that allows async calls with action
  handlers.

core/pkg/dbusutil/variant.go

@@ -0,0 +1,69 @@
+package dbusutil
+
+import "github.com/godbus/dbus/v5"
+
+func As[T any](v dbus.Variant) (T, bool) {
+	val, ok := v.Value().(T)
+	return val, ok
+}
+
+func AsOr[T any](v dbus.Variant, def T) T {
+	if val, ok := v.Value().(T); ok {
+		return val
+	}
+	return def
+}
+
+func Get[T any](m map[string]dbus.Variant, key string) (T, bool) {
+	v, ok := m[key]
+	if !ok {
+		var zero T
+		return zero, false
+	}
+	return As[T](v)
+}
+
+func GetOr[T any](m map[string]dbus.Variant, key string, def T) T {
+	v, ok := m[key]
+	if !ok {
+		return def
+	}
+	return AsOr(v, def)
+}
+
+func Normalize(v any) any {
+	switch val := v.(type) {
+	case dbus.Variant:
+		return Normalize(val.Value())
+	case dbus.ObjectPath:
+		return string(val)
+	case []dbus.ObjectPath:
+		result := make([]string, len(val))
+		for i, p := range val {
+			result[i] = string(p)
+		}
+		return result
+	case map[string]dbus.Variant:
+		result := make(map[string]any)
+		for k, vv := range val {
+			result[k] = Normalize(vv.Value())
+		}
+		return result
+	case []any:
+		result := make([]any, len(val))
+		for i, item := range val {
+			result[i] = Normalize(item)
+		}
+		return result
+	default:
+		return v
+	}
+}
+
+func NormalizeSlice(values []any) []any {
+	result := make([]any, len(values))
+	for i, v := range values {
+		result[i] = Normalize(v)
+	}
+	return result
+}

core/pkg/dbusutil/variant_test.go

@@ -0,0 +1,155 @@
+package dbusutil
+
+import (
+	"testing"
+
+	"github.com/godbus/dbus/v5"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestAs(t *testing.T) {
+	t.Run("string", func(t *testing.T) {
+		v := dbus.MakeVariant("hello")
+		val, ok := As[string](v)
+		assert.True(t, ok)
+		assert.Equal(t, "hello", val)
+	})
+
+	t.Run("bool", func(t *testing.T) {
+		v := dbus.MakeVariant(true)
+		val, ok := As[bool](v)
+		assert.True(t, ok)
+		assert.True(t, val)
+	})
+
+	t.Run("int32", func(t *testing.T) {
+		v := dbus.MakeVariant(int32(42))
+		val, ok := As[int32](v)
+		assert.True(t, ok)
+		assert.Equal(t, int32(42), val)
+	})
+
+	t.Run("wrong type", func(t *testing.T) {
+		v := dbus.MakeVariant("hello")
+		_, ok := As[int](v)
+		assert.False(t, ok)
+	})
+}
+
+func TestAsOr(t *testing.T) {
+	t.Run("exists", func(t *testing.T) {
+		v := dbus.MakeVariant("hello")
+		val := AsOr(v, "default")
+		assert.Equal(t, "hello", val)
+	})
+
+	t.Run("wrong type uses default", func(t *testing.T) {
+		v := dbus.MakeVariant(123)
+		val := AsOr(v, "default")
+		assert.Equal(t, "default", val)
+	})
+}
+
+func TestGet(t *testing.T) {
+	m := map[string]dbus.Variant{
+		"name":    dbus.MakeVariant("test"),
+		"enabled": dbus.MakeVariant(true),
+		"count":   dbus.MakeVariant(int32(5)),
+	}
+
+	t.Run("exists", func(t *testing.T) {
+		val, ok := Get[string](m, "name")
+		assert.True(t, ok)
+		assert.Equal(t, "test", val)
+	})
+
+	t.Run("missing key", func(t *testing.T) {
+		_, ok := Get[string](m, "missing")
+		assert.False(t, ok)
+	})
+
+	t.Run("wrong type", func(t *testing.T) {
+		_, ok := Get[int](m, "name")
+		assert.False(t, ok)
+	})
+}
+
+func TestGetOr(t *testing.T) {
+	m := map[string]dbus.Variant{
+		"name": dbus.MakeVariant("test"),
+	}
+
+	t.Run("exists", func(t *testing.T) {
+		val := GetOr(m, "name", "default")
+		assert.Equal(t, "test", val)
+	})
+
+	t.Run("missing uses default", func(t *testing.T) {
+		val := GetOr(m, "missing", "default")
+		assert.Equal(t, "default", val)
+	})
+
+	t.Run("wrong type uses default", func(t *testing.T) {
+		val := GetOr(m, "name", 42)
+		assert.Equal(t, 42, val)
+	})
+}
+
+func TestNormalize(t *testing.T) {
+	t.Run("variant unwrap", func(t *testing.T) {
+		v := dbus.MakeVariant("hello")
+		result := Normalize(v)
+		assert.Equal(t, "hello", result)
+	})
+
+	t.Run("nested variant", func(t *testing.T) {
+		v := dbus.MakeVariant(dbus.MakeVariant("nested"))
+		result := Normalize(v)
+		assert.Equal(t, "nested", result)
+	})
+
+	t.Run("object path", func(t *testing.T) {
+		v := dbus.ObjectPath("/org/test")
+		result := Normalize(v)
+		assert.Equal(t, "/org/test", result)
+	})
+
+	t.Run("object path slice", func(t *testing.T) {
+		v := []dbus.ObjectPath{"/org/a", "/org/b"}
+		result := Normalize(v)
+		assert.Equal(t, []string{"/org/a", "/org/b"}, result)
+	})
+
+	t.Run("variant map", func(t *testing.T) {
+		v := map[string]dbus.Variant{
+			"key": dbus.MakeVariant("value"),
+		}
+		result := Normalize(v)
+		expected := map[string]any{"key": "value"}
+		assert.Equal(t, expected, result)
+	})
+
+	t.Run("any slice", func(t *testing.T) {
+		v := []any{dbus.MakeVariant("a"), dbus.ObjectPath("/b")}
+		result := Normalize(v)
+		expected := []any{"a", "/b"}
+		assert.Equal(t, expected, result)
+	})
+
+	t.Run("passthrough primitives", func(t *testing.T) {
+		assert.Equal(t, "hello", Normalize("hello"))
+		assert.Equal(t, 42, Normalize(42))
+		assert.Equal(t, true, Normalize(true))
+	})
+}
+
+func TestNormalizeSlice(t *testing.T) {
+	input := []any{
+		dbus.MakeVariant("a"),
+		dbus.ObjectPath("/b"),
+		"c",
+	}
+	result := NormalizeSlice(input)
+	expected := []any{"a", "/b", "c"}
+	assert.Equal(t, expected, result)
+}