[feature] Add `/api/v1/admin/custom_emojis/{id}` endpoint for single emoji GET (#910)

* fix error in prev swagger docs

* add GET for single admin emoji

4 files changed, 61 insertions, 0 deletions

diff --git a/internal/processing/admin.go b/internal/processing/admin.go
index 59a4f8f1b..0ebce4d4e 100644
--- a/internal/processing/admin.go
+++ b/internal/processing/admin.go
@@ -38,6 +38,10 @@ func (p *processor) AdminEmojisGet(ctx context.Context, authed *oauth.Auth, doma
 	return p.adminProcessor.EmojisGet(ctx, authed.Account, authed.User, domain, includeDisabled, includeEnabled, shortcode, maxShortcodeDomain, minShortcodeDomain, limit)
 }
 
+func (p *processor) AdminEmojiGet(ctx context.Context, authed *oauth.Auth, id string) (*apimodel.AdminEmoji, gtserror.WithCode) {
+	return p.adminProcessor.EmojiGet(ctx, authed.Account, authed.User, id)
+}
+
 func (p *processor) AdminDomainBlockCreate(ctx context.Context, authed *oauth.Auth, form *apimodel.DomainBlockCreateRequest) (*apimodel.DomainBlock, gtserror.WithCode) {
 	return p.adminProcessor.DomainBlockCreate(ctx, authed.Account, form.Domain, form.Obfuscate, form.PublicComment, form.PrivateComment, "")
 }
diff --git a/internal/processing/admin/admin.go b/internal/processing/admin/admin.go
index 0de165fb9..49c02d3db 100644
--- a/internal/processing/admin/admin.go
+++ b/internal/processing/admin/admin.go
@@ -42,6 +42,7 @@ type Processor interface {
 	AccountAction(ctx context.Context, account *gtsmodel.Account, form *apimodel.AdminAccountActionRequest) gtserror.WithCode
 	EmojiCreate(ctx context.Context, account *gtsmodel.Account, user *gtsmodel.User, form *apimodel.EmojiCreateRequest) (*apimodel.Emoji, gtserror.WithCode)
 	EmojisGet(ctx context.Context, account *gtsmodel.Account, user *gtsmodel.User, domain string, includeDisabled bool, includeEnabled bool, shortcode string, maxShortcodeDomain string, minShortcodeDomain string, limit int) (*apimodel.PageableResponse, gtserror.WithCode)
+	EmojiGet(ctx context.Context, account *gtsmodel.Account, user *gtsmodel.User, id string) (*apimodel.AdminEmoji, gtserror.WithCode)
 	MediaPrune(ctx context.Context, mediaRemoteCacheDays int) gtserror.WithCode
 }
 
diff --git a/internal/processing/admin/getemoji.go b/internal/processing/admin/getemoji.go
new file mode 100644
index 000000000..ee3f997de
--- /dev/null
+++ b/internal/processing/admin/getemoji.go
@@ -0,0 +1,54 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package admin
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
+	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+)
+
+func (p *processor) EmojiGet(ctx context.Context, account *gtsmodel.Account, user *gtsmodel.User, id string) (*apimodel.AdminEmoji, gtserror.WithCode) {
+	if !*user.Admin {
+		return nil, gtserror.NewErrorUnauthorized(fmt.Errorf("user %s not an admin", user.ID), "user is not an admin")
+	}
+
+	emoji, err := p.db.GetEmojiByID(ctx, id)
+	if err != nil {
+		if errors.Is(err, db.ErrNoEntries) {
+			err = fmt.Errorf("EmojiGet: no emoji with id %s found in the db", id)
+			return nil, gtserror.NewErrorNotFound(err)
+		}
+		err := fmt.Errorf("EmojiGet: db error: %s", err)
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+
+	adminEmoji, err := p.tc.EmojiToAdminAPIEmoji(ctx, emoji)
+	if err != nil {
+		err = fmt.Errorf("EmojiGet: error converting emoji to admin api emoji: %s", err)
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+
+	return adminEmoji, nil
+}
diff --git a/internal/processing/processor.go b/internal/processing/processor.go
index b616511ea..ff465c926 100644
--- a/internal/processing/processor.go
+++ b/internal/processing/processor.go
@@ -114,6 +114,8 @@ type Processor interface {
 	AdminEmojiCreate(ctx context.Context, authed *oauth.Auth, form *apimodel.EmojiCreateRequest) (*apimodel.Emoji, gtserror.WithCode)
 	// AdminEmojisGet allows admins to view emojis based on various filters.
 	AdminEmojisGet(ctx context.Context, authed *oauth.Auth, domain string, includeDisabled bool, includeEnabled bool, shortcode string, maxShortcodeDomain string, minShortcodeDomain string, limit int) (*apimodel.PageableResponse, gtserror.WithCode)
+	// AdminEmojiGet returns the admin view of an emoji with the given ID
+	AdminEmojiGet(ctx context.Context, authed *oauth.Auth, id string) (*apimodel.AdminEmoji, gtserror.WithCode)
 	// AdminDomainBlockCreate handles the creation of a new domain block by an admin, using the given form.
 	AdminDomainBlockCreate(ctx context.Context, authed *oauth.Auth, form *apimodel.DomainBlockCreateRequest) (*apimodel.DomainBlock, gtserror.WithCode)
 	// AdminDomainBlocksImport handles the import of multiple domain blocks by an admin, using the given form.