checkpoint: add a type for representing the enum values of status visibility

internal/model/list.go

@@ -26,7 +26,7 @@ func ParseListRepliesPolicy(policy string) (ListRepliesPolicy, error) {
 		return ListRepliesPolicyNone, nil
 	}
 
-	return ListRepliesPolicy(-1), errors.New("invalid list replies policy")
+	return ListRepliesPolicy(-1), fmt.Errorf("%q is not a valid list replies policy", policy)
 }
 
 func (l ListRepliesPolicy) String() string {
@@ -43,12 +43,12 @@ func (l ListRepliesPolicy) String() string {
 }
 
 func (l ListRepliesPolicy) MarshalJSON() ([]byte, error) {
-	str := l.String()
+	value := l.String()
-	if str == "" {
+	if value == "" {
 		return nil, errors.New("invalid list replies policy")
 	}
 
-	return json.Marshal(str)
+	return json.Marshal(value)
 }
 
 func (l *ListRepliesPolicy) UnmarshalJSON(data []byte) error {

internal/model/status.go

@@ -1,6 +1,7 @@
 package model
 
 import (
+	"encoding/json"
 	"fmt"
 	"time"
 
@@ -36,7 +37,7 @@ type Status struct {
 	Text               string           `json:"text"`
 	URI                string           `json:"uri"`
 	URL                string           `json:"url"`
-	Visibility         string           `json:"visibility"`
+	Visibility         StatusVisibility `json:"visibility"`
 }
 
 type Card struct {
@@ -109,7 +110,7 @@ type StatusReblogged struct {
 	Text               string           `json:"text"`
 	URI                string           `json:"uri"`
 	URL                string           `json:"url"`
-	Visibility         string       `json:"visibility"`
+	Visibility         StatusVisibility `json:"visibility"`
 }
 
 type Tag struct {
@@ -195,3 +196,72 @@ func (s Status) String() string {
 		s.URL,
 	)
 }
+
+type StatusVisibility int
+
+const (
+	StatusVisibilityPublic StatusVisibility = iota
+	StatusVisibilityPrivate
+	StatusVisibilityUnlisted
+	StatusVisibilityMutualsOnly
+	StatusVisibilityDirect
+	StatusVisibilityUnknown
+)
+
+func (s StatusVisibility) String() string {
+	switch s {
+	case StatusVisibilityPublic:
+		return "public"
+	case StatusVisibilityPrivate:
+		return "private"
+	case StatusVisibilityUnlisted:
+		return "unlisted"
+	case StatusVisibilityMutualsOnly:
+		return "mutuals_only"
+	case StatusVisibilityDirect:
+		return "direct"
+	}
+
+	return "unknown"
+}
+
+func ParseStatusVisibility(visibility string) (StatusVisibility, error) {
+	switch visibility {
+	case "public":
+		return StatusVisibilityPublic, nil
+	case "private":
+		return StatusVisibilityPrivate, nil
+	case "unlisted":
+		return StatusVisibilityUnlisted, nil
+	case "mutuals_only":
+		return StatusVisibilityMutualsOnly, nil
+	case "direct":
+		return StatusVisibilityDirect, nil
+	}
+
+	return StatusVisibilityUnknown, nil
+}
+
+func (s StatusVisibility) MarshalJSON() ([]byte, error) {
+	value := s.String()
+	if value == "unknown" {
+		return nil, fmt.Errorf("%q is not a valid status visibility", value)
+	}
+
+	return json.Marshal(value)
+}
+
+func (s *StatusVisibility) UnmarshalJSON(data []byte) error {
+	var (
+		value string
+		err   error
+	)
+
+	if err = json.Unmarshal(data, &value); err != nil {
+		return fmt.Errorf("unable to unmarshal the data; %w", err)
+	}
+
+	*s, _ = ParseStatusVisibility(value)
+
+	return nil
+}