diff --git a/src/components/MessagesList/MessagesGroup/MessagesSystemGroup.vue b/src/components/MessagesList/MessagesGroup/MessagesSystemGroup.vue
index 0a77008eee4..56700d7d5fe 100644
--- a/src/components/MessagesList/MessagesGroup/MessagesSystemGroup.vue
+++ b/src/components/MessagesList/MessagesGroup/MessagesSystemGroup.vue
@@ -61,8 +61,6 @@
 </template>
 
 <script>
-import cloneDeep from 'lodash/cloneDeep.js'
-
 import UnfoldLess from 'vue-material-design-icons/UnfoldLessHorizontal.vue'
 import UnfoldMore from 'vue-material-design-icons/UnfoldMoreHorizontal.vue'
 
@@ -70,6 +68,8 @@ import NcButton from '@nextcloud/vue/dist/Components/NcButton.js'
 
 import Message from './Message/Message.vue'
 
+import { createCombinedSystemMessage } from '../../../utils/createCombinedSystemMessage.js'
+
 // List only sortable messages with order, in which they should be sorted
 const MESSAGES = {
 	user_added: 1,
@@ -151,6 +151,8 @@ export default {
 	},
 
 	methods: {
+		createCombinedSystemMessage,
+
 		/**
 		 * Compare two messages to decide if they should be grouped
 		 *
@@ -257,282 +259,6 @@ export default {
 			return groups
 		},
 
-		checkIfSelfIsActor(message) {
-			return message.messageParameters.actor.id === this.$store.getters.getActorId()
-				&& message.messageParameters.actor.type + 's' === this.$store.getters.getActorType()
-		},
-
-		checkIfSelfIsUser(message) {
-			return message.messageParameters.user.id === this.$store.getters.getActorId()
-				&& message.messageParameters.user.type + 's' === this.$store.getters.getActorType()
-		},
-
-		createCombinedSystemMessage({ messages, type }) {
-			const combinedMessage = cloneDeep(messages[0])
-
-			// Handle cases when users reconnected to the call
-			if (type === 'call_reconnected') {
-				if (this.checkIfSelfIsActor(combinedMessage)) {
-					combinedMessage.message = t('spreed', 'You reconnected to the call')
-				} else {
-					combinedMessage.message = t('spreed', '{actor} reconnected to the call')
-				}
-
-				return combinedMessage
-			}
-
-			// clear messageParameters to be filled later
-			const actor = messages[0].messageParameters.actor
-			combinedMessage.messageParameters = { actor }
-			const actorIsAdministrator = actor.id === 'guest/cli' && actor.type === 'guest'
-
-			// usersCounter should be equal at least 2, as we're using this method only for groups
-			let usersCounter = 0
-			let selfIsUser = false
-			let referenceIndex = 0
-
-			// Handle cases when actor added users to conversation (when populate on creation, for example)
-			if (type === 'user_added') {
-				const selfIsActor = combinedMessage.actorId === this.$store.getters.getActorId()
-					&& combinedMessage.actorType === this.$store.getters.getActorType()
-				messages.forEach(message => {
-					if (this.checkIfSelfIsUser(message)) {
-						selfIsUser = true
-					} else {
-						combinedMessage.messageParameters[`user${referenceIndex}`] = message.messageParameters.user
-						referenceIndex++
-					}
-					usersCounter++
-				})
-
-				if (selfIsActor) {
-					if (usersCounter === 2) {
-						combinedMessage.message = t('spreed', 'You added {user0} and {user1}')
-					} else {
-						combinedMessage.message = n('spreed',
-							'You added {user0}, {user1} and %n more participant',
-							'You added {user0}, {user1} and %n more participants', usersCounter - 2)
-					}
-				} else if (selfIsUser) {
-					if (usersCounter === 2) {
-						combinedMessage.message = actorIsAdministrator
-							? t('spreed', 'An administrator added you and {user0}')
-							: t('spreed', '{actor} added you and {user0}')
-					} else {
-						combinedMessage.message = actorIsAdministrator
-							? n('spreed',
-								'An administrator added you, {user0} and %n more participant',
-								'An administrator added you, {user0} and %n more participants', usersCounter - 2)
-							: n('spreed',
-								'{actor} added you, {user0} and %n more participant',
-								'{actor} added you, {user0} and %n more participants', usersCounter - 2)
-					}
-				} else {
-					if (usersCounter === 2) {
-						combinedMessage.message = actorIsAdministrator
-							? t('spreed', 'An administrator added {user0} and {user1}')
-							: t('spreed', '{actor} added {user0} and {user1}')
-					} else {
-						combinedMessage.message = actorIsAdministrator
-							? n('spreed',
-								'An administrator added {user0}, {user1} and %n more participant',
-								'An administrator added {user0}, {user1} and %n more participants', usersCounter - 2)
-							: n('spreed',
-								'{actor} added {user0}, {user1} and %n more participant',
-								'{actor} added {user0}, {user1} and %n more participants', usersCounter - 2)
-					}
-				}
-			}
-
-			// Used to hide duplicates from system message headers,
-			// when the same user joins or leaves call several times
-			const storedUniqueUsers = []
-
-			// Handle cases when users joined the call
-			if (type === 'call_joined') {
-				messages.forEach(message => {
-					const actorReference = `${message.messageParameters.actor.id}_${message.messageParameters.actor.type}`
-					if (storedUniqueUsers.includes(actorReference)) {
-						return
-					}
-					if (this.checkIfSelfIsActor(message)) {
-						selfIsUser = true
-					} else {
-						combinedMessage.messageParameters[`user${referenceIndex}`] = message.messageParameters.actor
-						storedUniqueUsers.push(actorReference)
-						referenceIndex++
-					}
-					usersCounter++
-				})
-
-				if (usersCounter === 1) {
-					combinedMessage.message = messages[0].message
-				} else if (selfIsUser) {
-					if (usersCounter === 2) {
-						combinedMessage.message = t('spreed', 'You and {user0} joined the call')
-					} else {
-						combinedMessage.message = n('spreed',
-							'You, {user0} and %n more participant joined the call',
-							'You, {user0} and %n more participants joined the call', usersCounter - 2)
-					}
-				} else {
-					if (usersCounter === 2) {
-						combinedMessage.message = t('spreed', '{user0} and {user1} joined the call')
-					} else {
-						combinedMessage.message = n('spreed',
-							'{user0}, {user1} and %n more participant joined the call',
-							'{user0}, {user1} and %n more participants joined the call', usersCounter - 2)
-					}
-				}
-			}
-
-			// Handle cases when users left the call
-			if (type === 'call_left') {
-				messages.forEach(message => {
-					const actorReference = `${message.messageParameters.actor.id}_${message.messageParameters.actor.type}`
-					if (storedUniqueUsers.includes(actorReference)) {
-						return
-					}
-					if (this.checkIfSelfIsActor(message)) {
-						selfIsUser = true
-					} else {
-						combinedMessage.messageParameters[`user${referenceIndex}`] = message.messageParameters.actor
-						storedUniqueUsers.push(actorReference)
-						referenceIndex++
-					}
-					usersCounter++
-				})
-
-				if (usersCounter === 1) {
-					combinedMessage.message = messages[0].message
-				} else if (selfIsUser) {
-					 if (usersCounter === 2) {
-						combinedMessage.message = t('spreed', 'You and {user0} left the call')
-					} else {
-						combinedMessage.message = n('spreed',
-							'You, {user0} and %n more participant left the call',
-							'You, {user0} and %n more participants left the call', usersCounter - 2)
-					}
-				} else {
-					if (usersCounter === 2) {
-						combinedMessage.message = t('spreed', '{user0} and {user1} left the call')
-					} else {
-						combinedMessage.message = n('spreed',
-							'{user0}, {user1} and %n more participant left the call',
-							'{user0}, {user1} and %n more participants left the call', usersCounter - 2)
-					}
-				}
-			}
-
-			// Handle cases when actor promoted several users to moderators
-			if (type === 'moderator_promoted') {
-				const selfIsActor = combinedMessage.actorId === this.$store.getters.getActorId()
-					&& combinedMessage.actorType === this.$store.getters.getActorType()
-				messages.forEach(message => {
-					if (this.checkIfSelfIsUser(message)) {
-						selfIsUser = true
-					} else {
-						combinedMessage.messageParameters[`user${referenceIndex}`] = message.messageParameters.user
-						referenceIndex++
-					}
-					usersCounter++
-				})
-
-				if (selfIsActor) {
-					if (usersCounter === 2) {
-						combinedMessage.message = t('spreed', 'You promoted {user0} and {user1} to moderators')
-					} else {
-						combinedMessage.message = n('spreed',
-							'You promoted {user0}, {user1} and %n more participant to moderators',
-							'You promoted {user0}, {user1} and %n more participants to moderators', usersCounter - 2)
-					}
-				} else if (selfIsUser) {
-					if (usersCounter === 2) {
-						combinedMessage.message = actorIsAdministrator
-							? t('spreed', 'An administrator promoted you and {user0} to moderators')
-							: t('spreed', '{actor} promoted you and {user0} to moderators')
-					} else {
-						combinedMessage.message = actorIsAdministrator
-							? n('spreed',
-								'An administrator promoted you, {user0} and %n more participant to moderators',
-								'An administrator promoted you, {user0} and %n more participants to moderators', usersCounter - 2)
-							: n('spreed',
-								'{actor} promoted you, {user0} and %n more participant to moderators',
-								'{actor} promoted you, {user0} and %n more participants to moderators', usersCounter - 2)
-					}
-				} else {
-					if (usersCounter === 2) {
-						combinedMessage.message = actorIsAdministrator
-							? t('spreed', 'An administrator promoted {user0} and {user1} to moderators')
-							: t('spreed', '{actor} promoted {user0} and {user1} to moderators')
-					} else {
-						combinedMessage.message = actorIsAdministrator
-							? n('spreed',
-								'An administrator promoted {user0}, {user1} and %n more participant to moderators',
-								'An administrator promoted {user0}, {user1} and %n more participants to moderators', usersCounter - 2)
-							: n('spreed',
-								'{actor} promoted {user0}, {user1} and %n more participant to moderators',
-								'{actor} promoted {user0}, {user1} and %n more participants to moderators', usersCounter - 2)
-					}
-				}
-			}
-
-			// Handle cases when actor demoted several users from moderators
-			if (type === 'moderator_demoted') {
-				const selfIsActor = combinedMessage.actorId === this.$store.getters.getActorId()
-					&& combinedMessage.actorType === this.$store.getters.getActorType()
-				messages.forEach(message => {
-					if (this.checkIfSelfIsUser(message)) {
-						selfIsUser = true
-					} else {
-						combinedMessage.messageParameters[`user${referenceIndex}`] = message.messageParameters.user
-						referenceIndex++
-					}
-					usersCounter++
-				})
-
-				if (selfIsActor) {
-					if (usersCounter === 2) {
-						combinedMessage.message = t('spreed', 'You demoted {user0} and {user1} from moderators')
-					} else {
-						combinedMessage.message = n('spreed',
-							'You demoted {user0}, {user1} and %n more participant from moderators',
-							'You demoted {user0}, {user1} and %n more participants from moderators', usersCounter - 2)
-					}
-				} else if (selfIsUser) {
-					if (usersCounter === 2) {
-						combinedMessage.message = actorIsAdministrator
-							? t('spreed', 'An administrator demoted you and {user0} from moderators')
-							: t('spreed', '{actor} demoted you and {user0} from moderators')
-					} else {
-						combinedMessage.message = actorIsAdministrator
-							? n('spreed',
-								'An administrator demoted you, {user0} and %n more participant from moderators',
-								'An administrator demoted you, {user0} and %n more participants from moderators', usersCounter - 2)
-							: n('spreed',
-								'{actor} demoted you, {user0} and %n more participant from moderators',
-								'{actor} demoted you, {user0} and %n more participants from moderators', usersCounter - 2)
-					}
-				} else {
-					if (usersCounter === 2) {
-						combinedMessage.message = actorIsAdministrator
-							? t('spreed', 'An administrator demoted {user0} and {user1} from moderators')
-							: t('spreed', '{actor} demoted {user0} and {user1} from moderators')
-					} else {
-						combinedMessage.message = actorIsAdministrator
-							? n('spreed',
-								'An administrator demoted {user0}, {user1} and %n more participant from moderators',
-								'An administrator demoted {user0}, {user1} and %n more participants from moderators', usersCounter - 2)
-							: n('spreed',
-								'{actor} demoted {user0}, {user1} and %n more participant from moderators',
-								'{actor} demoted {user0}, {user1} and %n more participants from moderators', usersCounter - 2)
-					}
-				}
-			}
-
-			return combinedMessage
-		},
-
 		toggleCollapsed(messages) {
 			this.$set(messages, 'collapsed', !messages.collapsed)
 			this.groupIsCollapsed[messages.id] = !this.groupIsCollapsed[messages.id]
diff --git a/src/utils/createCombinedSystemMessage.js b/src/utils/createCombinedSystemMessage.js
new file mode 100644
index 00000000000..5824b31f386
--- /dev/null
+++ b/src/utils/createCombinedSystemMessage.js
@@ -0,0 +1,305 @@
+/*
+ * @copyright Copyright (c) 2023 Maksim Sukharev <antreesy.web@gmail.com>
+ *
+ * @author Maksim Sukharev <antreesy.web@gmail.com>
+ *
+ * @license AGPL-3.0-or-later
+ *
+ * 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/>.
+ */
+
+import cloneDeep from 'lodash/cloneDeep.js'
+
+import store from '../store/index.js'
+
+/**
+ *
+ * @param {object} message message to check for
+ * @return {boolean}
+ */
+function checkIfSelfIsActor(message) {
+	return message.actorId === store.getters.getActorId()
+		&& message.actorType === store.getters.getActorType()
+}
+
+/**
+ *
+ * @param {object} message message to check for
+ * @return {boolean}
+ */
+function checkIfSelfIsOneOfActors(message) {
+	return message.messageParameters.actor.id === store.getters.getActorId()
+		&& message.messageParameters.actor.type + 's' === store.getters.getActorType()
+}
+
+/**
+ *
+ * @param {object} message message to check for
+ * @return {boolean}
+ */
+function checkIfSelfIsOneOfUsers(message) {
+	return message.messageParameters.user.id === store.getters.getActorId()
+		&& message.messageParameters.user.type + 's' === store.getters.getActorType()
+}
+
+/**
+ *
+ * @param {object} object props object
+ * @param {Array} object.messages array of collapsed messages
+ * @param {string} object.type type of combined message
+ * @return {object}
+ */
+export function createCombinedSystemMessage({ messages, type }) {
+	const combinedMessage = cloneDeep(messages[0])
+
+	// Handle cases when users reconnected to the call
+	if (type === 'call_reconnected') {
+		if (checkIfSelfIsOneOfActors(combinedMessage)) {
+			combinedMessage.message = t('spreed', 'You reconnected to the call')
+		} else {
+			combinedMessage.message = t('spreed', '{actor} reconnected to the call')
+		}
+
+		return combinedMessage
+	}
+
+	// clear messageParameters to be filled later
+	const actor = messages[0].messageParameters.actor
+	combinedMessage.messageParameters = { actor }
+	const actorIsAdministrator = actor.id === 'guest/cli' && actor.type === 'guest'
+
+	// usersCounter should be equal at least 2, as we're using method only for groups
+	let usersCounter = 0
+	let selfIsUser = false
+	let referenceIndex = 0
+
+	// Handle cases when actor added users to conversation (when populate on creation, for example)
+	if (type === 'user_added') {
+		messages.forEach(message => {
+			if (checkIfSelfIsOneOfUsers(message)) {
+				selfIsUser = true
+			} else {
+				combinedMessage.messageParameters[`user${referenceIndex}`] = message.messageParameters.user
+				referenceIndex++
+			}
+			usersCounter++
+		})
+
+		if (checkIfSelfIsActor(combinedMessage)) {
+			if (usersCounter === 2) {
+				combinedMessage.message = t('spreed', 'You added {user0} and {user1}')
+			} else {
+				combinedMessage.message = n('spreed',
+					'You added {user0}, {user1} and %n more participant',
+					'You added {user0}, {user1} and %n more participants', usersCounter - 2)
+			}
+		} else if (selfIsUser) {
+			if (usersCounter === 2) {
+				combinedMessage.message = actorIsAdministrator
+					? t('spreed', 'An administrator added you and {user0}')
+					: t('spreed', '{actor} added you and {user0}')
+			} else {
+				combinedMessage.message = actorIsAdministrator
+					? n('spreed',
+						'An administrator added you, {user0} and %n more participant',
+						'An administrator added you, {user0} and %n more participants', usersCounter - 2)
+					: n('spreed',
+						'{actor} added you, {user0} and %n more participant',
+						'{actor} added you, {user0} and %n more participants', usersCounter - 2)
+			}
+		} else {
+			if (usersCounter === 2) {
+				combinedMessage.message = actorIsAdministrator
+					? t('spreed', 'An administrator added {user0} and {user1}')
+					: t('spreed', '{actor} added {user0} and {user1}')
+			} else {
+				combinedMessage.message = actorIsAdministrator
+					? n('spreed',
+						'An administrator added {user0}, {user1} and %n more participant',
+						'An administrator added {user0}, {user1} and %n more participants', usersCounter - 2)
+					: n('spreed',
+						'{actor} added {user0}, {user1} and %n more participant',
+						'{actor} added {user0}, {user1} and %n more participants', usersCounter - 2)
+			}
+		}
+	}
+
+	// Handle cases when users joined or left the call
+	if (type === 'call_joined' || type === 'call_left') {
+		const storedUniqueUsers = []
+
+		messages.forEach(message => {
+			const actorReference = `${message.messageParameters.actor.id}_${message.messageParameters.actor.type}`
+			if (storedUniqueUsers.includes(actorReference)) {
+				return
+			}
+			if (checkIfSelfIsOneOfActors(message)) {
+				selfIsUser = true
+			} else {
+				combinedMessage.messageParameters[`user${referenceIndex}`] = message.messageParameters.actor
+				storedUniqueUsers.push(actorReference)
+				referenceIndex++
+			}
+			usersCounter++
+		})
+
+		if (usersCounter === 1) {
+			combinedMessage.message = messages[0].message
+			return combinedMessage
+		}
+
+		if (type === 'call_joined') {
+			if (selfIsUser) {
+				if (usersCounter === 2) {
+					combinedMessage.message = t('spreed', 'You and {user0} joined the call')
+				} else {
+					combinedMessage.message = n('spreed',
+						'You, {user0} and %n more participant joined the call',
+						'You, {user0} and %n more participants joined the call', usersCounter - 2)
+				}
+			} else {
+				if (usersCounter === 2) {
+					combinedMessage.message = t('spreed', '{user0} and {user1} joined the call')
+				} else {
+					combinedMessage.message = n('spreed',
+						'{user0}, {user1} and %n more participant joined the call',
+						'{user0}, {user1} and %n more participants joined the call', usersCounter - 2)
+				}
+			}
+		} else if (type === 'call_left') {
+			 if (selfIsUser) {
+				if (usersCounter === 2) {
+					combinedMessage.message = t('spreed', 'You and {user0} left the call')
+				} else {
+					combinedMessage.message = n('spreed',
+						'You, {user0} and %n more participant left the call',
+						'You, {user0} and %n more participants left the call', usersCounter - 2)
+				}
+			} else {
+				if (usersCounter === 2) {
+					combinedMessage.message = t('spreed', '{user0} and {user1} left the call')
+				} else {
+					combinedMessage.message = n('spreed',
+						'{user0}, {user1} and %n more participant left the call',
+						'{user0}, {user1} and %n more participants left the call', usersCounter - 2)
+				}
+			}
+		}
+
+	}
+
+	// Handle cases when actor promoted several users to moderators
+	if (type === 'moderator_promoted') {
+		messages.forEach(message => {
+			if (checkIfSelfIsOneOfUsers(message)) {
+				selfIsUser = true
+			} else {
+				combinedMessage.messageParameters[`user${referenceIndex}`] = message.messageParameters.user
+				referenceIndex++
+			}
+			usersCounter++
+		})
+
+		if (checkIfSelfIsActor(combinedMessage)) {
+			if (usersCounter === 2) {
+				combinedMessage.message = t('spreed', 'You promoted {user0} and {user1} to moderators')
+			} else {
+				combinedMessage.message = n('spreed',
+					'You promoted {user0}, {user1} and %n more participant to moderators',
+					'You promoted {user0}, {user1} and %n more participants to moderators', usersCounter - 2)
+			}
+		} else if (selfIsUser) {
+			if (usersCounter === 2) {
+				combinedMessage.message = actorIsAdministrator
+					? t('spreed', 'An administrator promoted you and {user0} to moderators')
+					: t('spreed', '{actor} promoted you and {user0} to moderators')
+			} else {
+				combinedMessage.message = actorIsAdministrator
+					? n('spreed',
+						'An administrator promoted you, {user0} and %n more participant to moderators',
+						'An administrator promoted you, {user0} and %n more participants to moderators', usersCounter - 2)
+					: n('spreed',
+						'{actor} promoted you, {user0} and %n more participant to moderators',
+						'{actor} promoted you, {user0} and %n more participants to moderators', usersCounter - 2)
+			}
+		} else {
+			if (usersCounter === 2) {
+				combinedMessage.message = actorIsAdministrator
+					? t('spreed', 'An administrator promoted {user0} and {user1} to moderators')
+					: t('spreed', '{actor} promoted {user0} and {user1} to moderators')
+			} else {
+				combinedMessage.message = actorIsAdministrator
+					? n('spreed',
+						'An administrator promoted {user0}, {user1} and %n more participant to moderators',
+						'An administrator promoted {user0}, {user1} and %n more participants to moderators', usersCounter - 2)
+					: n('spreed',
+						'{actor} promoted {user0}, {user1} and %n more participant to moderators',
+						'{actor} promoted {user0}, {user1} and %n more participants to moderators', usersCounter - 2)
+			}
+		}
+	}
+
+	// Handle cases when actor demoted several users from moderators
+	if (type === 'moderator_demoted') {
+		messages.forEach(message => {
+			if (checkIfSelfIsOneOfUsers(message)) {
+				selfIsUser = true
+			} else {
+				combinedMessage.messageParameters[`user${referenceIndex}`] = message.messageParameters.user
+				referenceIndex++
+			}
+			usersCounter++
+		})
+
+		if (checkIfSelfIsActor(combinedMessage)) {
+			if (usersCounter === 2) {
+				combinedMessage.message = t('spreed', 'You demoted {user0} and {user1} from moderators')
+			} else {
+				combinedMessage.message = n('spreed',
+					'You demoted {user0}, {user1} and %n more participant from moderators',
+					'You demoted {user0}, {user1} and %n more participants from moderators', usersCounter - 2)
+			}
+		} else if (selfIsUser) {
+			if (usersCounter === 2) {
+				combinedMessage.message = actorIsAdministrator
+					? t('spreed', 'An administrator demoted you and {user0} from moderators')
+					: t('spreed', '{actor} demoted you and {user0} from moderators')
+			} else {
+				combinedMessage.message = actorIsAdministrator
+					? n('spreed',
+						'An administrator demoted you, {user0} and %n more participant from moderators',
+						'An administrator demoted you, {user0} and %n more participants from moderators', usersCounter - 2)
+					: n('spreed',
+						'{actor} demoted you, {user0} and %n more participant from moderators',
+						'{actor} demoted you, {user0} and %n more participants from moderators', usersCounter - 2)
+			}
+		} else {
+			if (usersCounter === 2) {
+				combinedMessage.message = actorIsAdministrator
+					? t('spreed', 'An administrator demoted {user0} and {user1} from moderators')
+					: t('spreed', '{actor} demoted {user0} and {user1} from moderators')
+			} else {
+				combinedMessage.message = actorIsAdministrator
+					? n('spreed',
+						'An administrator demoted {user0}, {user1} and %n more participant from moderators',
+						'An administrator demoted {user0}, {user1} and %n more participants from moderators', usersCounter - 2)
+					: n('spreed',
+						'{actor} demoted {user0}, {user1} and %n more participant from moderators',
+						'{actor} demoted {user0}, {user1} and %n more participants from moderators', usersCounter - 2)
+			}
+		}
+	}
+
+	return combinedMessage
+}