tasks 00d, 006, 007: move test seams to struct fields, centralize Viper config, extract shared card-dir logic

task 00d: remove package-level var test seams from processor and gui packages;
  factory functions (newAudioProvider, newOpenAIImageClient, newNanoBananaImageClient)
  are now struct fields on Processor and Application, initialized with production
  defaults in constructors and replaced in tests without global mutation.

task 006: add viperConfig struct captured once in NewProcessor; no method body
  calls viper.GetString/IsSet/GetFloat64 directly any more — all config-file values
  are accessed via p.viperCfg fields.

task 007: extract FindCardDirectory and FindOrCreateCardDirectory into
  internal/utils.go; both Processor.findCardDirectory and
  Application.findCardDirectory now delegate to the shared implementation,
  which also handles the legacy _word.txt backward-compat fallback.

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

1 files changed, 59 insertions, 0 deletions

diff --git a/internal/utils.go b/internal/utils.go
index 47513ae..b83d46a 100644
--- a/internal/utils.go
+++ b/internal/utils.go
@@ -4,6 +4,8 @@ import (
 	"crypto/md5"
 	"encoding/hex"
 	"fmt"
+	"os"
+	"path/filepath"
 	"strings"
 	"time"
 )
@@ -23,6 +25,63 @@ func GenerateCardID(bulgarianWord string) string {
 	return fmt.Sprintf("%d_%s", epochMillis, hashStr)
 }
 
+// FindCardDirectory searches outputDir for a subdirectory whose word.txt
+// (or legacy _word.txt) matches the given word. Returns the directory path
+// or an empty string if not found.
+func FindCardDirectory(outputDir, word string) string {
+	entries, err := os.ReadDir(outputDir)
+	if err != nil {
+		return ""
+	}
+
+	for _, entry := range entries {
+		if !entry.IsDir() || strings.HasPrefix(entry.Name(), ".") {
+			continue
+		}
+
+		dirPath := filepath.Join(outputDir, entry.Name())
+		wordFile := filepath.Join(dirPath, "word.txt")
+
+		if data, err := os.ReadFile(wordFile); err == nil {
+			if strings.TrimSpace(string(data)) == word {
+				return dirPath
+			}
+		} else {
+			// Backward-compatible fallback: old format used _word.txt
+			wordFile = filepath.Join(dirPath, "_word.txt")
+			if data, err := os.ReadFile(wordFile); err == nil {
+				if strings.TrimSpace(string(data)) == word {
+					return dirPath
+				}
+			}
+		}
+	}
+
+	return ""
+}
+
+// FindOrCreateCardDirectory returns the existing card directory for word inside
+// outputDir, or creates a new one with a generated card ID. It also writes
+// word.txt so subsequent calls can find the directory.
+func FindOrCreateCardDirectory(outputDir, word string) string {
+	if dir := FindCardDirectory(outputDir, word); dir != "" {
+		return dir
+	}
+
+	cardID := GenerateCardID(word)
+	wordDir := filepath.Join(outputDir, cardID)
+	if err := os.MkdirAll(wordDir, 0755); err != nil {
+		fmt.Printf("Warning: failed to create word directory: %v\n", err)
+		return outputDir
+	}
+
+	if err := os.WriteFile(filepath.Join(wordDir, "word.txt"), []byte(word), 0644); err != nil {
+		fmt.Printf("Warning: failed to save word metadata: %v\n", err)
+	}
+
+	return wordDir
+}
+
 // SanitizeFilename creates a safe filename from a string.
 // Uses strings.Builder to avoid per-rune heap allocations.
 func SanitizeFilename(s string) string {