feat: replace fs scans with bbolt for fast, persistent metadata management

Signed-off-by: skidoodle <contact@albert.lol>

internal/app/db_test.go

@@ -0,0 +1,85 @@
+package app
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"go.etcd.io/bbolt"
+)
+
+func TestInitDB(t *testing.T) {
+	tmpDir := t.TempDir()
+
+	db, err := InitDB(tmpDir)
+	if err != nil {
+		t.Fatalf("InitDB failed: %v", err)
+	}
+	defer db.Close()
+
+	dbPath := filepath.Join(tmpDir, DBFileName)
+	if _, err := os.Stat(dbPath); os.IsNotExist(err) {
+		t.Error("Database file was not created")
+	}
+
+	err = db.View(func(tx *bbolt.Tx) error {
+		b := tx.Bucket([]byte(DBBucketName))
+		if b == nil {
+			t.Errorf("Bucket '%s' was not created", DBBucketName)
+		}
+		return nil
+	})
+	if err != nil {
+		t.Errorf("View failed: %v", err)
+	}
+}
+
+func TestDB_MetadataLifecycle(t *testing.T) {
+	tmpDir := t.TempDir()
+	db, err := InitDB(tmpDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	app := &App{
+		Conf: Config{StorageDir: tmpDir, MaxMB: 100},
+		DB:   db,
+	}
+
+	fileID := "test-file-id"
+	fileSize := int64(1024)
+
+	if err := app.RegisterFile(fileID, fileSize); err != nil {
+		t.Fatalf("RegisterFile failed: %v", err)
+	}
+
+	err = db.View(func(tx *bbolt.Tx) error {
+		b := tx.Bucket([]byte(DBBucketName))
+		data := b.Get([]byte(fileID))
+		if data == nil {
+			t.Fatal("Metadata not found in DB")
+		}
+
+		var meta FileMeta
+		if err := json.Unmarshal(data, &meta); err != nil {
+			t.Fatalf("Failed to unmarshal meta: %v", err)
+		}
+
+		if meta.ID != fileID {
+			t.Errorf("Want ID %s, got %s", fileID, meta.ID)
+		}
+		if meta.Size != fileSize {
+			t.Errorf("Want Size %d, got %d", fileSize, meta.Size)
+		}
+		if meta.ExpiresAt.Before(time.Now()) {
+			t.Error("Expiration time is in the past")
+		}
+		return nil
+	})
+	if err != nil {
+		t.Error(err)
+	}
+}