t7 centralize provider registries

2 files changed, 80 insertions, 6 deletions

diff --git a/internal/image/registry.go b/internal/image/registry.go
index 0338115..7b2a465 100644
--- a/internal/image/registry.go
+++ b/internal/image/registry.go
@@ -12,6 +12,9 @@ type Factory[C any] func(C) (ImageProvider, error)
 // Config exposes the configured image provider name.
 type Config interface {
 	ImageProviderName() string
+	GoogleAPIKey() string
+	ImageModel() string
+	ImageTextModel() string
 }
 
 // Registry resolves provider names to factories.
@@ -56,6 +59,12 @@ func (r *Registry[C]) Resolve(name string) (Factory[C], bool) {
 	return factory, ok
 }
 
+// Has reports whether a factory is registered for name.
+func (r *Registry[C]) Has(name string) bool {
+	_, ok := r.Resolve(name)
+	return ok
+}
+
 // New constructs a provider for name.
 func (r *Registry[C]) New(name string, cfg C) (ImageProvider, error) {
 	var zero ImageProvider
@@ -74,6 +83,26 @@ func (r *Registry[C]) NewFromConfig(cfg C) (ImageProvider, error) {
 	return r.New(cfg.ImageProviderName(), cfg)
 }
 
+// DefaultRegistry returns the built-in image provider registry.
+func DefaultRegistry() *Registry[Config] {
+	registry := NewRegistry[Config]()
+	registry.Register(Gemini, func(cfg Config) (ImageProvider, error) {
+		geminiProvider := NewGeminiProvider(&GeminiConfig{
+			APIKey:    cfg.GoogleAPIKey(),
+			Model:     cfg.ImageModel(),
+			TextModel: cfg.ImageTextModel(),
+		})
+		if err := geminiProvider.IsAvailable(); err != nil {
+			return nil, err
+		}
+		return geminiProvider, nil
+	})
+	registry.Register(OpenAI, func(Config) (ImageProvider, error) {
+		return nil, fmt.Errorf("image provider %q is not implemented", OpenAI)
+	})
+	return registry
+}
+
 func isNilValue[T any](value T) bool {
 	v := reflect.ValueOf(value)
 	if !v.IsValid() {
diff --git a/internal/image/types_test.go b/internal/image/types_test.go
index 9257392..4416870 100644
--- a/internal/image/types_test.go
+++ b/internal/image/types_test.go
@@ -53,21 +53,60 @@ func TestRegistryNewFromConfig(t *testing.T) {
 
 	registry := NewRegistry[fakeConfig]()
 	registry.Register(Gemini, func(cfg fakeConfig) (ImageProvider, error) {
-		return fakeProvider(cfg), nil
+		return fakeProvider{
+			name:  cfg.name,
+			token: cfg.token,
+		}, nil
 	})
 
-	provider, err := registry.NewFromConfig(fakeConfig{name: Gemini, token: "secret"})
+	gotProvider, err := registry.NewFromConfig(fakeConfig{name: Gemini, token: "secret"})
 	if err != nil {
 		t.Fatalf("NewFromConfig() error = %v", err)
 	}
-	if got, want := provider.Name(), Gemini; got != want {
+	if got, want := gotProvider.Name(), Gemini; got != want {
 		t.Fatalf("provider.Name() = %q, want %q", got, want)
 	}
-	if got, want := provider.(fakeProvider).token, "secret"; got != want {
+	if got, want := gotProvider.(fakeProvider).token, "secret"; got != want {
 		t.Fatalf("provider token = %q, want %q", got, want)
 	}
 }
 
+func TestDefaultRegistryNewFromConfig(t *testing.T) {
+	t.Parallel()
+
+	registry := DefaultRegistry()
+	gotProvider, err := registry.NewFromConfig(fakeConfig{
+		name:      Gemini,
+		apiKey:    "test-key",
+		model:     DefaultGeminiImageModel,
+		textModel: DefaultGeminiTextModel,
+	})
+	if err != nil {
+		t.Fatalf("NewFromConfig() error = %v", err)
+	}
+	if got, want := gotProvider.Name(), Gemini; got != want {
+		t.Fatalf("provider.Name() = %q, want %q", got, want)
+	}
+}
+
+func TestDefaultRegistryUnsupportedProvider(t *testing.T) {
+	t.Parallel()
+
+	registry := DefaultRegistry()
+	_, err := registry.NewFromConfig(fakeConfig{
+		name:      OpenAI,
+		apiKey:    "test-key",
+		model:     "unused",
+		textModel: "unused",
+	})
+	if err == nil {
+		t.Fatal("expected unsupported provider error")
+	}
+	if !strings.Contains(err.Error(), "image provider \"openai\" is not implemented") {
+		t.Fatalf("error = %v, want unsupported provider error", err)
+	}
+}
+
 func TestRegistryUnknownProvider(t *testing.T) {
 	t.Parallel()
 
@@ -82,11 +121,17 @@ func TestRegistryUnknownProvider(t *testing.T) {
 }
 
 type fakeConfig struct {
-	name  string
-	token string
+	name      string
+	token     string
+	apiKey    string
+	model     string
+	textModel string
 }
 
 func (f fakeConfig) ImageProviderName() string { return f.name }
+func (f fakeConfig) GoogleAPIKey() string      { return f.apiKey }
+func (f fakeConfig) ImageModel() string        { return f.model }
+func (f fakeConfig) ImageTextModel() string    { return f.textModel }
 
 type fakeProvider struct {
 	name  string