🏷️ Added Action domain

internal/domain/action.go

@@ -0,0 +1,68 @@
+package domain
+
+import (
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+// NOTE(toby3d): Encapsulate enums in structs for extra compile-time safety:
+// https://threedots.tech/post/safer-enums-in-go/#struct-based-enums
+type Action struct {
+	slug string
+}
+
+//nolint: gochecknoglobals // NOTE(toby3d): structs cannot be constants
+var (
+	ActionUndefined = Action{slug: ""}
+	ActionRevoke    = Action{slug: "revoke"}
+	ActionTicket    = Action{slug: "ticket"}
+)
+
+var ErrActionUnknown = errors.New("unknown action method")
+
+// ParseAction parse string identifier of action into struct enum.
+func ParseAction(slug string) (Action, error) {
+	switch strings.ToLower(slug) {
+	case ActionRevoke.slug:
+		return ActionRevoke, nil
+	case ActionTicket.slug:
+		return ActionTicket, nil
+	}
+
+	return ActionUndefined, fmt.Errorf("%w: %s", ErrActionUnknown, slug)
+}
+
+// UnmarshalForm implements custom unmarshler for form values.
+func (a *Action) UnmarshalForm(v []byte) error {
+	action, err := ParseAction(string(v))
+	if err != nil {
+		return fmt.Errorf("action: %w", err)
+	}
+
+	*a = action
+
+	return nil
+}
+
+func (a *Action) UnmarshalJSON(v []byte) error {
+	src, err := strconv.Unquote(string(v))
+	if err != nil {
+		return err
+	}
+
+	action, err := ParseAction(src)
+	if err != nil {
+		return fmt.Errorf("action: %w", err)
+	}
+
+	*a = action
+
+	return nil
+}
+
+// String returns string representation of action.
+func (a Action) String() string {
+	return a.slug
+}