maint(authd): Expose public API to build and parse UI layouts

README.md

@@ -47,7 +47,7 @@ in addition to information about authd architecture and troubleshooting.
 ## Brokers
 
 authd uses brokers to interface with cloud identity providers through a
-[DBus API](https://github.com/ubuntu/authd/blob/HEAD/examplebroker/com.ubuntu.auth.ExampleBroker.xml).
+[DBus API](https://github.com/ubuntu/authd/blob/HEAD/internal/examplebroker/com.ubuntu.auth.ExampleBroker.xml).
 
 Currently [MS Entra ID](https://learn.microsoft.com/en-us/entra/fundamentals/whatis)
 and [Google IAM](https://cloud.google.com/iam/docs/overview)

brokers/auth/generate.go

@@ -0,0 +1,5 @@
+//go:build generate
+
+//go:generate go run -tags generate ../../internal/cmd/types-parser -source-package "github.com/ubuntu/authd/internal/proto/authd" -types "authd.GAMResponse_AuthenticationMode" -types-aliases "Mode" -package auth -output ./authmode.go -converter ../../internal/proto/authd/authmode.go -converter-import "github.com/ubuntu/authd/brokers/auth" -converter-package "authd"
+
+package auth

brokers/auth/mode.go

@@ -0,0 +1,81 @@
+package auth
+
+import (
+	"fmt"
+
+	"github.com/ubuntu/authd/brokers/layouts"
+)
+
+// InvalidModeError defines an error for invalid [Mode] errors.
+type InvalidModeError struct {
+	Message string
+}
+
+// Error is the implementation of the error interface.
+func (e InvalidModeError) Error() string {
+	return e.Message
+}
+
+// Is makes this error insensitive to the actual error content.
+func (InvalidModeError) Is(err error) bool { return err == InvalidModeError{} }
+
+// ModeOptions is the function signature used to tweak the qrcode.
+type ModeOptions func(*Mode)
+
+// NewMode allows to create a new [Mode] with [ModeOptions].
+func NewMode(id, label string, opts ...ModeOptions) Mode {
+	mode := Mode{Id: id, Label: label}
+	for _, opt := range opts {
+		opt(&mode)
+	}
+
+	return mode
+}
+
+// ToMap creates a string map from the [Mode] that is used by DBus protocol.
+func (mode Mode) ToMap() (map[string]string, error) {
+	if mode.Id == "" {
+		return nil, InvalidModeError{"invalid empty mode ID"}
+	}
+	if mode.Label == "" {
+		return nil, InvalidModeError{"invalid empty mode label"}
+	}
+
+	return map[string]string{
+		layouts.ID:    mode.Id,
+		layouts.Label: mode.Label,
+	}, nil
+}
+
+// NewModeFromMap allows to create a new [Mode] from a map of strings how it's used in the DBus protocol.
+func NewModeFromMap(mode map[string]string) (Mode, error) {
+	id := mode[layouts.ID]
+	label := mode[layouts.Label]
+
+	if id == "" {
+		return Mode{}, InvalidModeError{
+			fmt.Sprintf("invalid authentication mode, missing %q key: %v", layouts.ID, mode),
+		}
+	}
+	if label == "" {
+		return Mode{}, InvalidModeError{
+			fmt.Sprintf("invalid authentication mode, missing %q key: %v", layouts.Label, mode),
+		}
+	}
+
+	return NewMode(id, label), nil
+}
+
+// NewModeMaps creates a list of string maps from the list of [Mode] how it's used by DBus protocol.
+func NewModeMaps(modes []Mode) ([]map[string]string, error) {
+	var maps []map[string]string
+
+	for _, m := range modes {
+		m, err := m.ToMap()
+		if err != nil {
+			return nil, err
+		}
+		maps = append(maps, m)
+	}
+	return maps, nil
+}

brokers/auth/mode_test.go

@@ -0,0 +1,152 @@
+package auth_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"github.com/ubuntu/authd/brokers/auth"
+	"github.com/ubuntu/authd/brokers/layouts"
+)
+
+func TestAuthModeMap(t *testing.T) {
+	t.Parallel()
+
+	testCases := map[string]struct {
+		id    string
+		label string
+
+		want      map[string]string
+		wantError error
+	}{
+		"Simple": {
+			id:    "some-id",
+			label: "Some Label",
+			want: map[string]string{
+				layouts.ID:    "some-id",
+				layouts.Label: "Some Label",
+			},
+		},
+
+		// Error cases.
+		"Error on Empty ID": {
+			wantError: auth.InvalidModeError{},
+		},
+		"Error on Empty Label": {
+			id:        "some-id",
+			wantError: auth.InvalidModeError{},
+		},
+	}
+	for name, tc := range testCases {
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			mode := auth.NewMode(tc.id, tc.label)
+			require.NotNil(t, mode, "Setup: Mode creation failed")
+
+			m, err := mode.ToMap()
+			require.ErrorIs(t, err, tc.wantError)
+			require.Equal(t, tc.want, m)
+
+			if tc.wantError != nil {
+				return
+			}
+
+			newMode, err := auth.NewModeFromMap(m)
+			require.NoError(t, err)
+			require.Equal(t, mode, newMode)
+		})
+	}
+}
+
+func TestAuthModesFromMapErrors(t *testing.T) {
+	t.Parallel()
+
+	testCases := map[string]struct {
+		id        string
+		wantError error
+	}{
+		"Error on Empty ID": {},
+		"Error on Empty Label": {
+			id: "some-id",
+		},
+	}
+	for name, tc := range testCases {
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			newMode, err := auth.NewModeFromMap(map[string]string{
+				layouts.ID: tc.id,
+			})
+			require.Zero(t, newMode, "Mode should be unset")
+			require.ErrorIs(t, err, auth.InvalidModeError{})
+		})
+	}
+}
+
+func TestModeList(t *testing.T) {
+	t.Parallel()
+
+	testCases := map[string]struct {
+		modes []auth.Mode
+
+		want      []map[string]string
+		wantError error
+	}{
+		"Empty": {},
+		"Single mode": {
+			modes: []auth.Mode{
+				auth.NewMode("some-id", "Some Label"),
+			},
+			want: []map[string]string{
+				{
+					layouts.ID:    "some-id",
+					layouts.Label: "Some Label",
+				},
+			},
+		},
+		"Multiple modes": {
+			modes: []auth.Mode{
+				auth.NewMode("some-id", "Some Label"),
+				auth.NewMode("some-other-id", "Some Other Label"),
+			},
+			want: []map[string]string{
+				{
+					layouts.ID:    "some-id",
+					layouts.Label: "Some Label",
+				},
+				{
+					layouts.ID:    "some-other-id",
+					layouts.Label: "Some Other Label",
+				},
+			},
+		},
+
+		// Error cases
+		"Error for invalid ID": {
+			modes: []auth.Mode{
+				auth.NewMode("some-id", "Some Label"),
+				auth.NewMode("", ""),
+				auth.NewMode("some-other-id", "Some Other Label"),
+			},
+			wantError: auth.InvalidModeError{},
+		},
+		// Error cases
+		"Error for invalid Label": {
+			modes: []auth.Mode{
+				auth.NewMode("some-id", "Some Label"),
+				auth.NewMode("some-id", ""),
+				auth.NewMode("some-other-id", "Some Other Label"),
+			},
+			wantError: auth.InvalidModeError{},
+		},
+	}
+	for name, tc := range testCases {
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			maps, err := auth.NewModeMaps(tc.modes)
+			require.ErrorIs(t, err, tc.wantError)
+			require.Equal(t, tc.want, maps)
+		})
+	}
+}

brokers/layouts/generate.go

@@ -0,0 +1,5 @@
+//go:build generate
+
+//go:generate go run -tags generate ../../internal/cmd/types-parser -source-package "github.com/ubuntu/authd/internal/proto/authd" -types "authd.UILayout" -types-aliases "UILayout" -package layouts -output ./uilayout.go -converter ../../internal/proto/authd/uilayout.go -converter-import "github.com/ubuntu/authd/brokers/layouts" -converter-package "authd"
+
+package layouts