feat(dialog): add dialog core.Service with Platform interface and IPC

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pkg/dialog/messages.go

@@ -0,0 +1,14 @@
+// pkg/dialog/messages.go
+package dialog
+
+// TaskOpenFile shows an open file dialog. Result: []string (paths)
+type TaskOpenFile struct{ Opts OpenFileOptions }
+
+// TaskSaveFile shows a save file dialog. Result: string (path)
+type TaskSaveFile struct{ Opts SaveFileOptions }
+
+// TaskOpenDirectory shows a directory picker. Result: string (path)
+type TaskOpenDirectory struct{ Opts OpenDirectoryOptions }
+
+// TaskMessageDialog shows a message dialog. Result: string (button clicked)
+type TaskMessageDialog struct{ Opts MessageDialogOptions }

pkg/dialog/platform.go

@@ -0,0 +1,59 @@
+// pkg/dialog/platform.go
+package dialog
+
+// Platform abstracts the native dialog backend.
+type Platform interface {
+	OpenFile(opts OpenFileOptions) ([]string, error)
+	SaveFile(opts SaveFileOptions) (string, error)
+	OpenDirectory(opts OpenDirectoryOptions) (string, error)
+	MessageDialog(opts MessageDialogOptions) (string, error)
+}
+
+// DialogType represents the type of message dialog.
+type DialogType int
+
+const (
+	DialogInfo DialogType = iota
+	DialogWarning
+	DialogError
+	DialogQuestion
+)
+
+// OpenFileOptions contains options for the open file dialog.
+type OpenFileOptions struct {
+	Title         string       `json:"title,omitempty"`
+	Directory     string       `json:"directory,omitempty"`
+	Filename      string       `json:"filename,omitempty"`
+	Filters       []FileFilter `json:"filters,omitempty"`
+	AllowMultiple bool         `json:"allowMultiple,omitempty"`
+}
+
+// SaveFileOptions contains options for the save file dialog.
+type SaveFileOptions struct {
+	Title     string       `json:"title,omitempty"`
+	Directory string       `json:"directory,omitempty"`
+	Filename  string       `json:"filename,omitempty"`
+	Filters   []FileFilter `json:"filters,omitempty"`
+}
+
+// OpenDirectoryOptions contains options for the directory picker.
+type OpenDirectoryOptions struct {
+	Title         string `json:"title,omitempty"`
+	Directory     string `json:"directory,omitempty"`
+	AllowMultiple bool   `json:"allowMultiple,omitempty"`
+}
+
+// MessageDialogOptions contains options for a message dialog.
+type MessageDialogOptions struct {
+	Type    DialogType `json:"type"`
+	Title   string     `json:"title"`
+	Message string     `json:"message"`
+	Buttons []string   `json:"buttons,omitempty"`
+}
+
+// FileFilter represents a file type filter for dialogs.
+type FileFilter struct {
+	DisplayName string   `json:"displayName"`
+	Pattern     string   `json:"pattern"`
+	Extensions  []string `json:"extensions,omitempty"`
+}

pkg/dialog/service.go

@@ -0,0 +1,57 @@
+// pkg/dialog/service.go
+package dialog
+
+import (
+	"context"
+
+	"forge.lthn.ai/core/go/pkg/core"
+)
+
+// Options holds configuration for the dialog service.
+type Options struct{}
+
+// Service is a core.Service managing native dialogs via IPC.
+type Service struct {
+	*core.ServiceRuntime[Options]
+	platform Platform
+}
+
+// Register creates a factory closure that captures the Platform adapter.
+func Register(p Platform) func(*core.Core) (any, error) {
+	return func(c *core.Core) (any, error) {
+		return &Service{
+			ServiceRuntime: core.NewServiceRuntime[Options](c, Options{}),
+			platform:       p,
+		}, nil
+	}
+}
+
+// OnStartup registers IPC handlers.
+func (s *Service) OnStartup(ctx context.Context) error {
+	s.Core().RegisterTask(s.handleTask)
+	return nil
+}
+
+// HandleIPCEvents is auto-discovered by core.WithService.
+func (s *Service) HandleIPCEvents(c *core.Core, msg core.Message) error {
+	return nil
+}
+
+func (s *Service) handleTask(c *core.Core, t core.Task) (any, bool, error) {
+	switch t := t.(type) {
+	case TaskOpenFile:
+		paths, err := s.platform.OpenFile(t.Opts)
+		return paths, true, err
+	case TaskSaveFile:
+		path, err := s.platform.SaveFile(t.Opts)
+		return path, true, err
+	case TaskOpenDirectory:
+		path, err := s.platform.OpenDirectory(t.Opts)
+		return path, true, err
+	case TaskMessageDialog:
+		button, err := s.platform.MessageDialog(t.Opts)
+		return button, true, err
+	default:
+		return nil, false, nil
+	}
+}

pkg/dialog/service_test.go

@@ -0,0 +1,123 @@
+// pkg/dialog/service_test.go
+package dialog
+
+import (
+	"context"
+	"testing"
+
+	"forge.lthn.ai/core/go/pkg/core"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+type mockPlatform struct {
+	openFilePaths  []string
+	saveFilePath   string
+	openDirPath    string
+	messageButton  string
+	openFileErr    error
+	saveFileErr    error
+	openDirErr     error
+	messageErr     error
+	lastOpenOpts   OpenFileOptions
+	lastSaveOpts   SaveFileOptions
+	lastDirOpts    OpenDirectoryOptions
+	lastMsgOpts    MessageDialogOptions
+}
+
+func (m *mockPlatform) OpenFile(opts OpenFileOptions) ([]string, error) {
+	m.lastOpenOpts = opts
+	return m.openFilePaths, m.openFileErr
+}
+func (m *mockPlatform) SaveFile(opts SaveFileOptions) (string, error) {
+	m.lastSaveOpts = opts
+	return m.saveFilePath, m.saveFileErr
+}
+func (m *mockPlatform) OpenDirectory(opts OpenDirectoryOptions) (string, error) {
+	m.lastDirOpts = opts
+	return m.openDirPath, m.openDirErr
+}
+func (m *mockPlatform) MessageDialog(opts MessageDialogOptions) (string, error) {
+	m.lastMsgOpts = opts
+	return m.messageButton, m.messageErr
+}
+
+func newTestService(t *testing.T) (*mockPlatform, *core.Core) {
+	t.Helper()
+	mock := &mockPlatform{
+		openFilePaths: []string{"/tmp/file.txt"},
+		saveFilePath:  "/tmp/save.txt",
+		openDirPath:   "/tmp/dir",
+		messageButton: "OK",
+	}
+	c, err := core.New(
+		core.WithService(Register(mock)),
+		core.WithServiceLock(),
+	)
+	require.NoError(t, err)
+	require.NoError(t, c.ServiceStartup(context.Background(), nil))
+	return mock, c
+}
+
+func TestRegister_Good(t *testing.T) {
+	_, c := newTestService(t)
+	svc := core.MustServiceFor[*Service](c, "dialog")
+	assert.NotNil(t, svc)
+}
+
+func TestTaskOpenFile_Good(t *testing.T) {
+	mock, c := newTestService(t)
+	mock.openFilePaths = []string{"/a.txt", "/b.txt"}
+
+	result, handled, err := c.PERFORM(TaskOpenFile{
+		Opts: OpenFileOptions{Title: "Pick", AllowMultiple: true},
+	})
+	require.NoError(t, err)
+	assert.True(t, handled)
+	paths := result.([]string)
+	assert.Equal(t, []string{"/a.txt", "/b.txt"}, paths)
+	assert.Equal(t, "Pick", mock.lastOpenOpts.Title)
+	assert.True(t, mock.lastOpenOpts.AllowMultiple)
+}
+
+func TestTaskSaveFile_Good(t *testing.T) {
+	_, c := newTestService(t)
+	result, handled, err := c.PERFORM(TaskSaveFile{
+		Opts: SaveFileOptions{Filename: "out.txt"},
+	})
+	require.NoError(t, err)
+	assert.True(t, handled)
+	assert.Equal(t, "/tmp/save.txt", result)
+}
+
+func TestTaskOpenDirectory_Good(t *testing.T) {
+	_, c := newTestService(t)
+	result, handled, err := c.PERFORM(TaskOpenDirectory{
+		Opts: OpenDirectoryOptions{Title: "Pick Dir"},
+	})
+	require.NoError(t, err)
+	assert.True(t, handled)
+	assert.Equal(t, "/tmp/dir", result)
+}
+
+func TestTaskMessageDialog_Good(t *testing.T) {
+	mock, c := newTestService(t)
+	mock.messageButton = "Yes"
+
+	result, handled, err := c.PERFORM(TaskMessageDialog{
+		Opts: MessageDialogOptions{
+			Type: DialogQuestion, Title: "Confirm",
+			Message: "Sure?", Buttons: []string{"Yes", "No"},
+		},
+	})
+	require.NoError(t, err)
+	assert.True(t, handled)
+	assert.Equal(t, "Yes", result)
+	assert.Equal(t, DialogQuestion, mock.lastMsgOpts.Type)
+}
+
+func TestTaskOpenFile_Bad(t *testing.T) {
+	c, _ := core.New(core.WithServiceLock())
+	_, handled, _ := c.PERFORM(TaskOpenFile{})
+	assert.False(t, handled)
+}