zr: preserve Gemini init errors and docs

4 files changed, 62 insertions, 14 deletions

diff --git a/assets/config.yaml.example b/assets/config.yaml.example
index 3988035..18d4513 100644
--- a/assets/config.yaml.example
+++ b/assets/config.yaml.example
@@ -23,6 +23,17 @@ audio:
   # openai_instruction: "You are a Bulgarian language teacher. Pronounce the Bulgarian words slowly with authentic Bulgarian accent and phonetics."
   # openai_instruction: "Speak Bulgarian text with proper Bulgarian pronunciation. Avoid Russian accent. Speak clearly at a pace suitable for beginners."
 
+# Translation configuration
+translation:
+  # Translation backend used by internal/translation/translator.go
+  # Supported values: openai (default) or gemini
+  provider: openai
+
+# Google API settings
+google:
+  # Used by Gemini translation when translation.provider is set to gemini
+  api_key: ${GOOGLE_API_KEY}
+
 # Image configuration
 image:
   # Provider: currently only openai is supported
diff --git a/internal/processor/processor_test.go b/internal/processor/processor_test.go
index 9e6b5fc..d0a0070 100644
--- a/internal/processor/processor_test.go
+++ b/internal/processor/processor_test.go
@@ -110,9 +110,9 @@ func TestProcessSingleWord_InvalidWord(t *testing.T) {
 }
 
 func TestProcessSingleWord_ValidWord(t *testing.T) {
-	// Skip if no API key
-	if os.Getenv("OPENAI_API_KEY") == "" || os.Getenv("GOOGLE_API_KEY") == "" {
-		t.Skip("Skipping test: OPENAI_API_KEY and GOOGLE_API_KEY must be set")
+	// Skip if no OpenAI API key
+	if os.Getenv("OPENAI_API_KEY") == "" {
+		t.Skip("Skipping test: OPENAI_API_KEY must be set")
 	}
 
 	flags := cli.NewFlags()
@@ -162,9 +162,9 @@ func TestProcessBatch_ValidFile(t *testing.T) {
 	flags.SkipImages = true
 	p := NewProcessor(flags)
 
-	// Skip if no API keys
-	if os.Getenv("OPENAI_API_KEY") == "" || os.Getenv("GOOGLE_API_KEY") == "" {
-		t.Skip("Skipping test: OPENAI_API_KEY and GOOGLE_API_KEY must be set")
+	// Skip if no OpenAI API key
+	if os.Getenv("OPENAI_API_KEY") == "" {
+		t.Skip("Skipping test: OPENAI_API_KEY must be set")
 	}
 
 	err = p.ProcessBatch()
diff --git a/internal/translation/translator.go b/internal/translation/translator.go
index 1a3d3b2..09a1e67 100644
--- a/internal/translation/translator.go
+++ b/internal/translation/translator.go
@@ -47,15 +47,18 @@ func DefaultConfig() *Config {
 
 // Translator handles Bulgarian and English translation using the configured backend.
 type Translator struct {
-	provider     Provider
-	openAIKey    string
-	googleAPIKey string
-	openAIClient *openai.Client
-	geminiClient *genai.Client
-	openAIModel  string
-	geminiModel  string
+	provider      Provider
+	openAIKey     string
+	googleAPIKey  string
+	openAIClient  *openai.Client
+	geminiClient  *genai.Client
+	geminiInitErr error
+	openAIModel   string
+	geminiModel   string
 }
 
+var newGeminiClient = genai.NewClient
+
 // NewTranslator creates a new translator instance from the provided config.
 func NewTranslator(config *Config) *Translator {
 	if config == nil {
@@ -76,11 +79,13 @@ func NewTranslator(config *Config) *Translator {
 	}
 
 	if normalized.GoogleAPIKey != "" {
-		client, err := genai.NewClient(context.Background(), &genai.ClientConfig{
+		client, err := newGeminiClient(context.Background(), &genai.ClientConfig{
 			APIKey: normalized.GoogleAPIKey,
 		})
 		if err == nil {
 			translator.geminiClient = client
+		} else {
+			translator.geminiInitErr = err
 		}
 	}
 
@@ -169,6 +174,9 @@ func (t *Translator) translateWithGemini(prompt string) (string, error) {
 	if t.googleAPIKey == "" {
 		return "", fmt.Errorf("Google API key not found")
 	}
+	if t.geminiInitErr != nil {
+		return "", fmt.Errorf("Gemini client initialization failed: %w", t.geminiInitErr)
+	}
 	if t.geminiClient == nil {
 		return "", fmt.Errorf("Gemini client not initialized")
 	}
diff --git a/internal/translation/translator_test.go b/internal/translation/translator_test.go
index d506a1e..49f1f15 100644
--- a/internal/translation/translator_test.go
+++ b/internal/translation/translator_test.go
@@ -1,10 +1,14 @@
 package translation
 
 import (
+	"context"
+	"errors"
 	"os"
 	"path/filepath"
 	"reflect"
 	"testing"
+
+	"google.golang.org/genai"
 )
 
 func TestNewTranslator_DefaultsToOpenAI(t *testing.T) {
@@ -90,6 +94,31 @@ func TestTranslateWord_ExplicitGeminiRequiresGoogleAPIKey(t *testing.T) {
 	}
 }
 
+func TestTranslateWord_GeminiClientInitError(t *testing.T) {
+	originalNewGeminiClient := newGeminiClient
+	defer func() {
+		newGeminiClient = originalNewGeminiClient
+	}()
+
+	initErr := errors.New("boom")
+	newGeminiClient = func(context.Context, *genai.ClientConfig) (*genai.Client, error) {
+		return nil, initErr
+	}
+
+	translator := NewTranslator(&Config{
+		Provider:     ProviderGemini,
+		GoogleAPIKey: "test-google-key",
+	})
+
+	_, err := translator.TranslateWord("ябълка")
+	if err == nil {
+		t.Fatal("Expected Gemini init error")
+	}
+	if !errors.Is(err, initErr) {
+		t.Fatalf("Expected wrapped init error, got: %v", err)
+	}
+}
+
 func TestTranslateWord_IntegrationGemini(t *testing.T) {
 	apiKey := os.Getenv("GOOGLE_API_KEY")
 	if apiKey == "" {