STUFF

1 files changed, 41 insertions, 0 deletions

diff --git a/database/users.go b/database/users.go
index 169cce1..164a631 100644
--- a/database/users.go
+++ b/database/users.go
@@ -99,3 +99,44 @@ func AssociateMAC(db *sql.DB, mac, userID string) error {
 		mac, userID, now, now)
 	return err
 }
+
+// MACBelongsToUser reports whether a MAC is currently bound to the given user.
+func MACBelongsToUser(db *sql.DB, mac, userID string) (bool, error) {
+	var owner string
+	err := db.QueryRow("SELECT user_id FROM macs WHERE mac = ?", mac).Scan(&owner)
+	if errors.Is(err, sql.ErrNoRows) {
+		return false, nil
+	}
+	if err != nil {
+		return false, err
+	}
+	return owner == userID, nil
+}
+
+// SetUserPrimaryMAC sets the user's primary device (the MAC its
+// <username>.<zone> name points at).
+func SetUserPrimaryMAC(db *sql.DB, userID, mac string) error {
+	_, err := db.Exec("UPDATE users SET primary_mac = ? WHERE id = ?", mac, userID)
+	return err
+}
+
+// SetPrimaryMACIfUnset atomically makes mac the primary device only when the
+// user has none yet. The conditional WHERE makes "first device wins" race-free:
+// concurrent associations can't both win, and there's no read-then-write gap.
+func SetPrimaryMACIfUnset(db *sql.DB, userID, mac string) error {
+	_, err := db.Exec("UPDATE users SET primary_mac = ? WHERE id = ? AND primary_mac IS NULL", mac, userID)
+	return err
+}
+
+// GetUserPrimaryMAC returns the user's primary MAC, or "" if unset.
+func GetUserPrimaryMAC(db *sql.DB, userID string) (string, error) {
+	var mac sql.NullString
+	err := db.QueryRow("SELECT primary_mac FROM users WHERE id = ?", userID).Scan(&mac)
+	if errors.Is(err, sql.ErrNoRows) {
+		return "", ErrNotFound
+	}
+	if err != nil {
+		return "", err
+	}
+	return mac.String, nil
+}