refactor(KeySpec): moves over to a unified KeySpec struct for parsing

cmd/keyspec.go

@@ -0,0 +1,64 @@
+package cmd
+
+import (
+	"fmt"
+	"strings"
+)
+
+// KeySpec is a parsed key reference.
+type KeySpec struct {
+	Raw    string // Whole, unmodified user input
+	RawKey string // Key segment
+	RawDB  string // DB segment
+	Key    string // Normalised Key
+	DB     string // Normalised DB
+}
+
+// ParseKey parses "KEY[@DB]" into a normalized KeySpec.
+// When defaults is true, a missing DB defaults to "default".
+func ParseKey(raw string, defaults bool) (KeySpec, error) {
+	parts := strings.Split(raw, "@")
+	if len(parts) > 2 {
+		return KeySpec{}, fmt.Errorf("bad key format, use KEY@DB")
+	}
+
+	rawKey := parts[0]
+	rawDB := ""
+	if len(parts) == 2 {
+		rawDB = parts[1]
+		if strings.TrimSpace(rawDB) == "" {
+			return KeySpec{}, fmt.Errorf("bad key format, use KEY@DB")
+		}
+	}
+
+	key := strings.ToLower(rawKey)
+	db := strings.ToLower(rawDB)
+	if db == "" && defaults {
+		db = "default"
+	}
+
+	return KeySpec{
+		Raw:    raw,
+		RawKey: rawKey,
+		RawDB:  rawDB,
+		Key:    key,
+		DB:     db,
+	}, nil
+}
+
+// Full returns the whole normalized key reference.
+func (k KeySpec) Full() string {
+	if k.DB == "" {
+		return k.Key
+	}
+	return fmt.Sprintf("%s@%s", k.Key, k.DB)
+}
+
+// Display returns the normalized key reference
+// but omits the default database if none was set manually
+func (k KeySpec) Display() string {
+	if k.DB == "" || k.DB == "default" {
+		return k.Key
+	}
+	return fmt.Sprintf("%s@%s", k.Key, k.DB)
+}