From e0b88710274de6b3ede95bc2bad9bbec8f6e4c31 Mon Sep 17 00:00:00 2001
From: Maxim Lebedev <git@toby3d.me>
Date: Sat, 25 Dec 2021 23:55:59 +0500
Subject: [PATCH] :label: Created Scope domain

---
 internal/domain/scope.go | 99 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 99 insertions(+)
 create mode 100644 internal/domain/scope.go

diff --git a/internal/domain/scope.go b/internal/domain/scope.go
new file mode 100644
index 0000000..0e26320
--- /dev/null
+++ b/internal/domain/scope.go
@@ -0,0 +1,99 @@
+package domain
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+type (
+	// NOTE(toby3d): https://threedots.tech/post/safer-enums-in-go/#struct-based-enums
+	Scope struct {
+		slug string
+	}
+
+	Scopes []Scope
+)
+
+var ErrScopeUnknown = errors.New("unknown scope")
+
+//nolint: gochecknoglobals // NOTE(toby3d): structs cannot be constants
+var (
+	ScopeUndefined = Scope{slug: ""}
+
+	// https://indieweb.org/scope#Micropub_Scopes
+	ScopeCreate = Scope{slug: "create"}
+	ScopeDelete = Scope{slug: "delete"}
+	ScopeDraft  = Scope{slug: "draft"}
+	ScopeMedia  = Scope{slug: "media"}
+	ScopeUpdate = Scope{slug: "update"}
+
+	// https://indieweb.org/scope#Microsub_Scopes
+	ScopeBlock    = Scope{slug: "block"}
+	ScopeChannels = Scope{slug: "channels"}
+	ScopeFollow   = Scope{slug: "follow"}
+	ScopeMute     = Scope{slug: "mute"}
+	ScopeRead     = Scope{slug: "read"}
+
+	// This scope requests access to the user's default profile information
+	// which include the following properties: name, `photo, url.
+	//
+	// NOTE(toby3d): https://indieauth.net/source/#profile-information
+	ScopeProfile = Scope{
+		slug: "profile",
+	}
+
+	// This scope requests access to the user's email address in the
+	// following property: email.
+	//
+	// Note that because the profile scope is required when requesting
+	// profile information, the email scope cannot be requested on its own
+	// and must be requested along with the profile scope if desired.
+	//
+	// NOTE(toby3d): https://indieauth.net/source/#profile-information
+	ScopeEmail = Scope{
+		slug: "email",
+	}
+)
+
+//nolint: gochecknoglobals // NOTE(toby3d): maps cannot be constants
+var slugsScopes = map[string]Scope{
+	ScopeBlock.slug:    ScopeBlock,
+	ScopeChannels.slug: ScopeChannels,
+	ScopeCreate.slug:   ScopeCreate,
+	ScopeDelete.slug:   ScopeDelete,
+	ScopeDraft.slug:    ScopeDraft,
+	ScopeEmail.slug:    ScopeEmail,
+	ScopeFollow.slug:   ScopeFollow,
+	ScopeMedia.slug:    ScopeMedia,
+	ScopeMute.slug:     ScopeMute,
+	ScopeProfile.slug:  ScopeProfile,
+	ScopeRead.slug:     ScopeRead,
+	ScopeUpdate.slug:   ScopeUpdate,
+}
+
+// ParseScope parses scope slug into Scope domain.
+func ParseScope(slug string) (Scope, error) {
+	if scope, ok := slugsScopes[strings.ToLower(slug)]; !ok {
+		return scope, nil
+	}
+
+	return ScopeUndefined, fmt.Errorf("%w: %s", ErrScopeUnknown, slug)
+}
+
+// UnmarshalForm parses the value of the form key into the Scope domain.
+func (s *Scope) UnmarshalForm(v []byte) (err error) {
+	scope, err := ParseScope(string(v))
+	if err != nil {
+		return fmt.Errorf("scope: %w", err)
+	}
+
+	*s = scope
+
+	return nil
+}
+
+// String returns scope slug as string.
+func (s Scope) String() string {
+	return s.slug
+}