Add names for link shares (#829)

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/api/pulls/829
Co-authored-by: konrad <konrad@kola-entertainments.de>
Co-committed-by: konrad <konrad@kola-entertainments.de>

pkg/models/users.go

@@ -0,0 +1,78 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-2021 Vikunja and contributors. All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public Licensee 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 Licensee for more details.
+//
+// You should have received a copy of the GNU Affero General Public Licensee
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package models
+
+import (
+	"code.vikunja.io/api/pkg/user"
+	"code.vikunja.io/web"
+	"xorm.io/xorm"
+)
+
+// Returns either a user or a link share disguised as a user.
+func getUserOrLinkShareUser(s *xorm.Session, a web.Auth) (uu *user.User, err error) {
+	if u, is := a.(*user.User); is {
+		uu, err = user.GetUserByID(s, u.ID)
+		return
+	}
+
+	if ls, is := a.(*LinkSharing); is {
+		l, err := GetLinkShareByID(s, ls.ID)
+		if err != nil {
+			return nil, err
+		}
+		return l.toUser(), nil
+	}
+
+	return
+}
+
+// Returns all users or pseudo link shares from a slice of ids. ids < 0 are considered to be a link share in that case.
+func getUsersOrLinkSharesFromIDs(s *xorm.Session, ids []int64) (users map[int64]*user.User, err error) {
+	users = make(map[int64]*user.User)
+	var userIDs []int64
+	var linkShareIDs []int64
+	for _, id := range ids {
+		if id < 0 {
+			linkShareIDs = append(linkShareIDs, id*-1)
+			continue
+		}
+
+		userIDs = append(userIDs, id)
+	}
+
+	if len(userIDs) > 0 {
+		users, err = user.GetUsersByIDs(s, userIDs)
+		if err != nil {
+			return
+		}
+	}
+
+	if len(linkShareIDs) == 0 {
+		return
+	}
+
+	shares, err := GetLinkSharesByIDs(s, linkShareIDs)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, share := range shares {
+		users[share.ID*-1] = share.toUser()
+	}
+
+	return
+}