15 files changed, 1080 insertions, 0 deletions
diff --git a/lib/public/Activity/ActivitySettings.php b/lib/public/Activity/ActivitySettings.php
new file mode 100644
index 00000000000..fa187164e19
--- /dev/null
+++ b/lib/public/Activity/ActivitySettings.php
@@ -0,0 +1,98 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2020 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCP\Activity;
+
+/**
+ * @since 20.0.0
+ */
+abstract class ActivitySettings implements ISetting {
+	/**
+	 * @return string Lowercase a-z and underscore only identifier
+	 * @since 20.0.0
+	 */
+	abstract public function getIdentifier();
+
+	/**
+	 * @return string A translated string
+	 * @since 20.0.0
+	 */
+	abstract public function getName();
+
+	/**
+	 * @return string Lowercase a-z and underscore only group identifier
+	 * @since 20.0.0
+	 */
+	abstract public function getGroupIdentifier();
+
+	/**
+	 * @return string A translated string for the settings group
+	 * @since 20.0.0
+	 */
+	abstract public function getGroupName();
+
+	/**
+	 * @return int whether the filter should be rather on the top or bottom of
+	 *             the admin section. The filters are arranged in ascending order of the
+	 *             priority values. It is required to return a value between 0 and 100.
+	 * @since 20.0.0
+	 */
+	abstract public function getPriority();
+
+	/**
+	 * @return bool True when the option can be changed for the mail
+	 * @since 20.0.0
+	 */
+	public function canChangeMail() {
+		return true;
+	}
+
+	/**
+	 * @return bool True when the option can be changed for the notification
+	 * @since 20.0.0
+	 */
+	public function canChangeNotification() {
+		return true;
+	}
+
+	/**
+	 * @return bool Whether or not an activity email should be send by default
+	 * @since 20.0.0
+	 */
+	public function isDefaultEnabledMail() {
+		return false;
+	}
+
+	/**
+	 * @return bool Whether or not an activity notification should be send by default
+	 * @since 20.0.0
+	 */
+	public function isDefaultEnabledNotification() {
+		return $this->isDefaultEnabledMail() && !$this->canChangeMail();
+	}
+
+	/**
+	 * Left in for backwards compatibility
+	 *
+	 * @return bool
+	 * @since 20.0.0
+	 */
+	public function canChangeStream() {
+		return false;
+	}
+
+	/**
+	 * Left in for backwards compatibility
+	 *
+	 * @return bool
+	 * @since 20.0.0
+	 */
+	public function isDefaultEnabledStream() {
+		return true;
+	}
+}
diff --git a/lib/public/Activity/Exceptions/FilterNotFoundException.php b/lib/public/Activity/Exceptions/FilterNotFoundException.php
new file mode 100644
index 00000000000..e3461f9b3e3
--- /dev/null
+++ b/lib/public/Activity/Exceptions/FilterNotFoundException.php
@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCP\Activity\Exceptions;
+
+/**
+ * @since 30.0.0
+ */
+class FilterNotFoundException extends \InvalidArgumentException {
+	/**
+	 * @since 30.0.0
+	 */
+	public function __construct(
+		protected string $filter,
+	) {
+		parent::__construct('Filter ' . $filter . ' not found');
+	}
+
+	/**
+	 * @since 30.0.0
+	 */
+	public function getFilterId(): string {
+		return $this->filter;
+	}
+}
diff --git a/lib/public/Activity/Exceptions/IncompleteActivityException.php b/lib/public/Activity/Exceptions/IncompleteActivityException.php
new file mode 100644
index 00000000000..44f6b4aba58
--- /dev/null
+++ b/lib/public/Activity/Exceptions/IncompleteActivityException.php
@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCP\Activity\Exceptions;
+
+/**
+ * Thrown when {@see \OCP\Notification\IManager::notify()} is called with a notification
+ * that does not have all required fields set:
+ *
+ * - app
+ * - type
+ * - affectedUser
+ * - subject
+ * - objectType
+ * - objectId
+ *
+ * @since 30.0.0
+ */
+class IncompleteActivityException extends \BadMethodCallException {
+}
diff --git a/lib/public/Activity/Exceptions/InvalidValueException.php b/lib/public/Activity/Exceptions/InvalidValueException.php
new file mode 100644
index 00000000000..aa4b04ab199
--- /dev/null
+++ b/lib/public/Activity/Exceptions/InvalidValueException.php
@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCP\Activity\Exceptions;
+
+/**
+ * @since 30.0.0
+ */
+class InvalidValueException extends \InvalidArgumentException {
+	/**
+	 * @since 30.0.0
+	 */
+	public function __construct(
+		protected string $field,
+		?\Throwable $previous = null,
+	) {
+		parent::__construct('Value provided for ' . $field . ' is not valid', previous: $previous);
+	}
+
+	/**
+	 * @since 30.0.0
+	 */
+	public function getFieldIdentifier(): string {
+		return $this->field;
+	}
+}
diff --git a/lib/public/Activity/Exceptions/SettingNotFoundException.php b/lib/public/Activity/Exceptions/SettingNotFoundException.php
new file mode 100644
index 00000000000..d0847c19cd2
--- /dev/null
+++ b/lib/public/Activity/Exceptions/SettingNotFoundException.php
@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCP\Activity\Exceptions;
+
+/**
+ * @since 30.0.0
+ */
+class SettingNotFoundException extends \InvalidArgumentException {
+	/**
+	 * @since 30.0.0
+	 */
+	public function __construct(
+		protected string $setting,
+	) {
+		parent::__construct('Setting ' . $setting . ' not found');
+	}
+
+	/**
+	 * @since 30.0.0
+	 */
+	public function getSettingId(): string {
+		return $this->setting;
+	}
+}
diff --git a/lib/public/Activity/Exceptions/UnknownActivityException.php b/lib/public/Activity/Exceptions/UnknownActivityException.php
new file mode 100644
index 00000000000..5567ddf2534
--- /dev/null
+++ b/lib/public/Activity/Exceptions/UnknownActivityException.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCP\Activity\Exceptions;
+
+/**
+ * @since 30.0.0
+ */
+class UnknownActivityException extends \InvalidArgumentException {
+}
diff --git a/lib/public/Activity/IBulkConsumer.php b/lib/public/Activity/IBulkConsumer.php
new file mode 100644
index 00000000000..9fdf3516b9a
--- /dev/null
+++ b/lib/public/Activity/IBulkConsumer.php
@@ -0,0 +1,24 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCP\Activity;
+
+/**
+ * Interface IBulkConsumer
+ *
+ * @since 32.0.0
+ */
+interface IBulkConsumer extends IConsumer {
+	/**
+	 * @param IEvent $event
+	 * @param array $affectedUserIds
+	 * @param ISetting $setting
+	 * @return void
+	 * @since 32.0.0
+	 */
+	public function bulkReceive(IEvent $event, array $affectedUserIds, ISetting $setting): void;
+}
diff --git a/lib/public/Activity/IConsumer.php b/lib/public/Activity/IConsumer.php
new file mode 100644
index 00000000000..4cf35ea5a44
--- /dev/null
+++ b/lib/public/Activity/IConsumer.php
@@ -0,0 +1,26 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+// use OCP namespace for all classes that are considered public.
+// This means that they should be used by apps instead of the internal Nextcloud classes
+
+namespace OCP\Activity;
+
+/**
+ * Interface IConsumer
+ *
+ * @since 6.0.0
+ */
+interface IConsumer {
+	/**
+	 * @param IEvent $event
+	 * @return null
+	 * @since 6.0.0
+	 * @since 8.2.0 Replaced the parameters with an IEvent object
+	 */
+	public function receive(IEvent $event);
+}
diff --git a/lib/public/Activity/IEvent.php b/lib/public/Activity/IEvent.php
new file mode 100644
index 00000000000..6014b75123c
--- /dev/null
+++ b/lib/public/Activity/IEvent.php
@@ -0,0 +1,378 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2016 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+// use OCP namespace for all classes that are considered public.
+// This means that they should be used by apps instead of the internal Nextcloud classes
+
+namespace OCP\Activity;
+
+use OCP\Activity\Exceptions\InvalidValueException;
+
+/**
+ * Interface IEvent
+ *
+ * @since 8.2.0
+ */
+interface IEvent {
+	/**
+	 * Set the app of the activity
+	 *
+	 * @param string $app
+	 * @return IEvent
+	 * @throws InvalidValueException if the app id is invalid
+	 * @since 8.2.0
+	 * @since 30.0.0 throws {@see InvalidValueException} instead of \InvalidArgumentException
+	 */
+	public function setApp(string $app): self;
+
+	/**
+	 * Set the type of the activity
+	 *
+	 * @param string $type
+	 * @return IEvent
+	 * @throws InvalidValueException if the type is invalid
+	 * @since 8.2.0
+	 * @since 30.0.0 throws {@see InvalidValueException} instead of \InvalidArgumentException
+	 */
+	public function setType(string $type): self;
+
+	/**
+	 * Set the affected user of the activity
+	 *
+	 * @param string $affectedUser
+	 * @return IEvent
+	 * @throws InvalidValueException if the affected user is invalid
+	 * @since 8.2.0
+	 * @since 30.0.0 throws {@see InvalidValueException} instead of \InvalidArgumentException
+	 */
+	public function setAffectedUser(string $affectedUser): self;
+
+	/**
+	 * Set the author of the activity
+	 *
+	 * @param string $author
+	 * @return IEvent
+	 * @throws InvalidValueException if the author is invalid
+	 * @since 8.2.0
+	 * @since 30.0.0 throws {@see InvalidValueException} instead of \InvalidArgumentException
+	 */
+	public function setAuthor(string $author): self;
+
+	/**
+	 * Set the author of the activity
+	 *
+	 * @param int $timestamp
+	 * @return IEvent
+	 * @throws InvalidValueException if the timestamp is invalid
+	 * @since 8.2.0
+	 * @since 30.0.0 throws {@see InvalidValueException} instead of \InvalidArgumentException
+	 */
+	public function setTimestamp(int $timestamp): self;
+
+	/**
+	 * Set the subject of the activity
+	 *
+	 * @param string $subject
+	 * @param array $parameters
+	 * @return IEvent
+	 * @throws InvalidValueException if the subject or parameters are invalid
+	 * @since 8.2.0
+	 * @since 30.0.0 throws {@see InvalidValueException} instead of \InvalidArgumentException
+	 */
+	public function setSubject(string $subject, array $parameters = []): self;
+
+	/**
+	 * Set a parsed subject
+	 *
+	 * HTML is not allowed in the parsed subject and will be escaped
+	 * automatically by the clients. You can use the RichObjectString system
+	 * provided by the Nextcloud server to highlight important parameters via
+	 * the setRichSubject method.
+	 *
+	 * See https://github.com/nextcloud/server/issues/1706 for more information.
+	 *
+	 * @param string $subject
+	 * @return $this
+	 * @throws InvalidValueException if the subject is invalid
+	 * @since 11.0.0
+	 * @since 30.0.0 throws {@see InvalidValueException} instead of \InvalidArgumentException
+	 */
+	public function setParsedSubject(string $subject): self;
+
+	/**
+	 * @return string
+	 * @since 11.0.0
+	 */
+	public function getParsedSubject(): string;
+
+	/**
+	 * Set a RichObjectString subject
+	 *
+	 * HTML is not allowed in the rich subject and will be escaped automatically
+	 * by the clients, but you can use the RichObjectString system provided by
+	 * the Nextcloud server to highlight important parameters.
+	 *
+	 * See https://github.com/nextcloud/server/issues/1706 for more information.
+	 *
+	 * @param string $subject
+	 * @param array<string, array<string, string>> $parameters
+	 * @return $this
+	 * @throws InvalidValueException if the subject or parameters are invalid
+	 * @since 11.0.0
+	 * @since 30.0.0 throws {@see InvalidValueException} instead of \InvalidArgumentException
+	 */
+	public function setRichSubject(string $subject, array $parameters = []): self;
+
+	/**
+	 * @return string
+	 * @since 11.0.0
+	 */
+	public function getRichSubject(): string;
+
+	/**
+	 * @return array<string, array<string, string>>
+	 * @since 11.0.0
+	 */
+	public function getRichSubjectParameters(): array;
+
+	/**
+	 * Set the message of the activity
+	 *
+	 * @param string $message
+	 * @param array $parameters
+	 * @return IEvent
+	 * @throws InvalidValueException if the message or parameters are invalid
+	 * @since 8.2.0
+	 * @since 30.0.0 throws {@see InvalidValueException} instead of \InvalidArgumentException
+	 */
+	public function setMessage(string $message, array $parameters = []): self;
+
+	/**
+	 * Set a parsed message
+	 *
+	 * HTML is not allowed in the parsed message and will be escaped
+	 * automatically by the clients. You can use the RichObjectString system
+	 * provided by the Nextcloud server to highlight important parameters via
+	 * the setRichMessage method.
+	 *
+	 * See https://github.com/nextcloud/server/issues/1706 for more information.
+	 *
+	 * @param string $message
+	 * @return $this
+	 * @throws InvalidValueException if the message is invalid
+	 * @since 11.0.0
+	 * @since 30.0.0 throws {@see InvalidValueException} instead of \InvalidArgumentException
+	 */
+	public function setParsedMessage(string $message): self;
+
+	/**
+	 * @return string
+	 * @since 11.0.0
+	 */
+	public function getParsedMessage(): string;
+
+	/**
+	 * Set a RichObjectString message
+	 *
+	 * HTML is not allowed in the rich message and will be escaped automatically
+	 * by the clients, but you can use the RichObjectString system provided by
+	 * the Nextcloud server to highlight important parameters.
+	 *
+	 * See https://github.com/nextcloud/server/issues/1706 for more information.
+	 *
+	 * @param string $message
+	 * @param array<string, array<string, string>> $parameters
+	 * @return $this
+	 * @throws \InvalidArgumentException if the message or parameters are invalid
+	 * @since 11.0.0
+	 * @since 30.0.0 throws {@see InvalidValueException} instead of \InvalidArgumentException
+	 */
+	public function setRichMessage(string $message, array $parameters = []): self;
+
+	/**
+	 * @return string
+	 * @since 11.0.0
+	 */
+	public function getRichMessage(): string;
+
+	/**
+	 * @return array<string, array<string, string>>
+	 * @since 11.0.0
+	 */
+	public function getRichMessageParameters(): array;
+
+	/**
+	 * Set the object of the activity
+	 *
+	 * @param string $objectType
+	 * @param int $objectId
+	 * @param string $objectName
+	 * @return IEvent
+	 * @throws InvalidValueException if the object is invalid
+	 * @since 8.2.0
+	 * @since 30.0.0 throws {@see InvalidValueException} instead of \InvalidArgumentException
+	 */
+	public function setObject(string $objectType, int $objectId, string $objectName = ''): self;
+
+	/**
+	 * Set the link of the activity
+	 *
+	 * @param string $link
+	 * @return IEvent
+	 * @throws InvalidValueException if the link is invalid
+	 * @since 8.2.0
+	 * @since 30.0.0 throws {@see InvalidValueException} instead of \InvalidArgumentException
+	 */
+	public function setLink(string $link): self;
+
+	/**
+	 * @return string
+	 * @since 8.2.0
+	 */
+	public function getApp(): string;
+
+	/**
+	 * @return string
+	 * @since 8.2.0
+	 */
+	public function getType(): string;
+
+	/**
+	 * @return string
+	 * @since 8.2.0
+	 */
+	public function getAffectedUser(): string;
+
+	/**
+	 * @return string
+	 * @since 8.2.0
+	 */
+	public function getAuthor(): string;
+
+	/**
+	 * @return int
+	 * @since 8.2.0
+	 */
+	public function getTimestamp(): int;
+
+	/**
+	 * @return string
+	 * @since 8.2.0
+	 */
+	public function getSubject(): string;
+
+	/**
+	 * @return array
+	 * @since 8.2.0
+	 */
+	public function getSubjectParameters(): array;
+
+	/**
+	 * @return string
+	 * @since 8.2.0
+	 */
+	public function getMessage(): string;
+
+	/**
+	 * @return array
+	 * @since 8.2.0
+	 */
+	public function getMessageParameters(): array;
+
+	/**
+	 * @return string
+	 * @since 8.2.0
+	 */
+	public function getObjectType(): string;
+
+	/**
+	 * @return int
+	 * @since 8.2.0
+	 */
+	public function getObjectId(): int;
+
+	/**
+	 * @return string
+	 * @since 8.2.0
+	 */
+	public function getObjectName(): string;
+
+	/**
+	 * @return string
+	 * @since 8.2.0
+	 */
+	public function getLink(): string;
+
+	/**
+	 * Set the absolute url for the icon (should be colored black or not have a color)
+	 *
+	 * It's automatically color inverted by clients when needed
+	 *
+	 * @param string $icon
+	 * @return $this
+	 * @throws InvalidValueException if the icon is invalid
+	 * @since 11.0.0
+	 * @since 30.0.0 throws {@see InvalidValueException} instead of \InvalidArgumentException
+	 */
+	public function setIcon(string $icon): self;
+
+	/**
+	 * Get the absolute url for the icon (should be colored black or not have a color)
+	 *
+	 * It's automatically color inverted by clients when needed
+	 *
+	 * @return string
+	 * @since 11.0.0
+	 */
+	public function getIcon(): string;
+
+	/**
+	 * @param IEvent $child
+	 * @return $this
+	 * @since 11.0.0 - Since 15.0.0 returns $this
+	 */
+	public function setChildEvent(IEvent $child): self;
+
+	/**
+	 * @return IEvent|null
+	 * @since 11.0.0
+	 */
+	public function getChildEvent();
+
+	/**
+	 * @return bool
+	 * @since 11.0.0
+	 */
+	public function isValid(): bool;
+
+	/**
+	 * @return bool
+	 * @since 11.0.0
+	 */
+	public function isValidParsed(): bool;
+
+	/**
+	 * Set whether a notification should be automatically generated for this activity.
+	 *
+	 * Set this to `false` if the app already generates a notification for the event.
+	 *
+	 * @param bool $generate
+	 * @return IEvent
+	 * @since 20.0.0
+	 */
+	public function setGenerateNotification(bool $generate): self;
+
+	/**
+	 * Whether a notification should be automatically generated for this activity.
+	 *
+	 * @return bool
+	 * @since 20.0.0
+	 */
+	public function getGenerateNotification(): bool;
+}
diff --git a/lib/public/Activity/IEventMerger.php b/lib/public/Activity/IEventMerger.php
new file mode 100644
index 00000000000..5d0f691f2d4
--- /dev/null
+++ b/lib/public/Activity/IEventMerger.php
@@ -0,0 +1,45 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2016 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCP\Activity;
+
+/**
+ * Interface EventMerger
+ *
+ * @since 11.0
+ */
+interface IEventMerger {
+	/**
+	 * Combines two events when possible to have grouping:
+	 *
+	 * Example1: Two events with subject '{user} created {file}' and
+	 * $mergeParameter file with different file and same user will be merged
+	 * to '{user} created {file1} and {file2}' and the childEvent on the return
+	 * will be set, if the events have been merged.
+	 *
+	 * Example2: Two events with subject '{user} created {file}' and
+	 * $mergeParameter file with same file and same user will be merged to
+	 * '{user} created {file1}' and the childEvent on the return will be set, if
+	 * the events have been merged.
+	 *
+	 * The following requirements have to be met, in order to be merged:
+	 * - Both events need to have the same `getApp()`
+	 * - Both events must not have a message `getMessage()`
+	 * - Both events need to have the same subject `getSubject()`
+	 * - Both events need to have the same object type `getObjectType()`
+	 * - The time difference between both events must not be bigger then 3 hours
+	 * - Only up to 5 events can be merged.
+	 * - All parameters apart from such starting with $mergeParameter must be
+	 *   the same for both events.
+	 *
+	 * @param string $mergeParameter
+	 * @param IEvent $event
+	 * @param IEvent|null $previousEvent
+	 * @return IEvent
+	 * @since 11.0
+	 */
+	public function mergeEvents($mergeParameter, IEvent $event, ?IEvent $previousEvent = null);
+}
diff --git a/lib/public/Activity/IExtension.php b/lib/public/Activity/IExtension.php
new file mode 100644
index 00000000000..c85d8ce5ed9
--- /dev/null
+++ b/lib/public/Activity/IExtension.php
@@ -0,0 +1,55 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+namespace OCP\Activity;
+
+/**
+ * Interface IExtension
+ *
+ * @since 8.0.0
+ */
+interface IExtension {
+	/**
+	 * @since 8.0.0
+	 */
+	public const METHOD_STREAM = 'stream';
+
+	/**
+	 * @since 8.0.0
+	 */
+	public const METHOD_MAIL = 'email';
+
+	/**
+	 * @since 20.0.0
+	 */
+	public const METHOD_NOTIFICATION = 'notification';
+
+	/**
+	 * @since 8.0.0
+	 */
+	public const PRIORITY_VERYLOW = 10;
+
+	/**
+	 * @since 8.0.0
+	 */
+	public const PRIORITY_LOW = 20;
+
+	/**
+	 * @since 8.0.0
+	 */
+	public const PRIORITY_MEDIUM = 30;
+
+	/**
+	 * @since 8.0.0
+	 */
+	public const PRIORITY_HIGH = 40;
+
+	/**
+	 * @since 8.0.0
+	 */
+	public const PRIORITY_VERYHIGH = 50;
+}
diff --git a/lib/public/Activity/IFilter.php b/lib/public/Activity/IFilter.php
new file mode 100644
index 00000000000..008de6f5bca
--- /dev/null
+++ b/lib/public/Activity/IFilter.php
@@ -0,0 +1,53 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2016 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCP\Activity;
+
+/**
+ * Interface IFilter
+ *
+ * @since 11.0.0
+ */
+interface IFilter {
+	/**
+	 * @return string Lowercase a-z and underscore only identifier
+	 * @since 11.0.0
+	 */
+	public function getIdentifier();
+
+	/**
+	 * @return string A translated string
+	 * @since 11.0.0
+	 */
+	public function getName();
+
+	/**
+	 * @return int whether the filter should be rather on the top or bottom of
+	 *             the admin section. The filters are arranged in ascending order of the
+	 *             priority values. It is required to return a value between 0 and 100.
+	 * @since 11.0.0
+	 */
+	public function getPriority();
+
+	/**
+	 * @return string Full URL to an icon, empty string when none is given
+	 * @since 11.0.0
+	 */
+	public function getIcon();
+
+	/**
+	 * @param string[] $types
+	 * @return string[] An array of allowed apps from which activities should be displayed
+	 * @since 11.0.0
+	 */
+	public function filterTypes(array $types);
+
+	/**
+	 * @return string[] An array of allowed apps from which activities should be displayed
+	 * @since 11.0.0
+	 */
+	public function allowedApps();
+}
diff --git a/lib/public/Activity/IManager.php b/lib/public/Activity/IManager.php
new file mode 100644
index 00000000000..d638b8b2c6b
--- /dev/null
+++ b/lib/public/Activity/IManager.php
@@ -0,0 +1,176 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+namespace OCP\Activity;
+
+use OCP\Activity\Exceptions\FilterNotFoundException;
+use OCP\Activity\Exceptions\IncompleteActivityException;
+use OCP\Activity\Exceptions\SettingNotFoundException;
+
+/**
+ * Interface IManager
+ *
+ * @since 6.0.0
+ */
+interface IManager {
+	/**
+	 * Generates a new IEvent object
+	 *
+	 * Make sure to call at least the following methods before sending it to the
+	 * app with via the publish() method:
+	 *  - setApp()
+	 *  - setType()
+	 *  - setAffectedUser()
+	 *  - setSubject()
+	 *  - setObject()
+	 *
+	 * @return IEvent
+	 * @since 8.2.0
+	 */
+	public function generateEvent(): IEvent;
+
+	/**
+	 * Publish an event to the activity consumers
+	 *
+	 * Make sure to call at least the following methods before sending an Event:
+	 *  - setApp()
+	 *  - setType()
+	 *  - setAffectedUser()
+	 *  - setSubject()
+	 *  - setObject()
+	 *
+	 * @param IEvent $event
+	 * @throws IncompleteActivityException if required values have not been set
+	 * @since 8.2.0
+	 * @since 30.0.0 throws {@see IncompleteActivityException} instead of \BadMethodCallException
+	 */
+	public function publish(IEvent $event): void;
+
+	/**
+	 * Bulk publish an event for multiple users
+	 * taking into account the app specific activity settings
+	 *
+	 * Make sure to call at least the following methods before sending an Event:
+	 *  - setApp()
+	 *  - setType()
+	 *
+	 * @param IEvent $event
+	 * @throws IncompleteActivityException if required values have not been set
+	 * @since 32.0.0
+	 */
+	public function bulkPublish(IEvent $event, array $affectedUserIds, ISetting $setting): void;
+
+	/**
+	 * In order to improve lazy loading a closure can be registered which will be called in case
+	 * activity consumers are actually requested
+	 *
+	 * $callable has to return an instance of \OCP\Activity\IConsumer
+	 *
+	 * @param \Closure $callable
+	 * @since 6.0.0
+	 */
+	public function registerConsumer(\Closure $callable): void;
+
+	/**
+	 * @param string $filter Class must implement OCA\Activity\IFilter
+	 * @since 11.0.0
+	 */
+	public function registerFilter(string $filter): void;
+
+	/**
+	 * @return IFilter[]
+	 * @since 11.0.0
+	 */
+	public function getFilters(): array;
+
+	/**
+	 * @param string $id
+	 * @return IFilter
+	 * @throws FilterNotFoundException when the filter was not found
+	 * @since 11.0.0
+	 * @since 30.0.0 throws {@see FilterNotFoundException} instead of \InvalidArgumentException
+	 */
+	public function getFilterById(string $id): IFilter;
+
+	/**
+	 * @param string $setting Class must implement OCA\Activity\ISetting
+	 * @since 11.0.0
+	 */
+	public function registerSetting(string $setting): void;
+
+	/**
+	 * @return ActivitySettings[]
+	 * @since 11.0.0
+	 */
+	public function getSettings(): array;
+
+	/**
+	 * @param string $provider Class must implement OCA\Activity\IProvider
+	 * @since 11.0.0
+	 */
+	public function registerProvider(string $provider): void;
+
+	/**
+	 * @return IProvider[]
+	 * @since 11.0.0
+	 */
+	public function getProviders(): array;
+
+	/**
+	 * @param string $id
+	 * @return ActivitySettings
+	 * @throws SettingNotFoundException when the setting was not found
+	 * @since 11.0.0
+	 * @since 30.0.0 throws {@see SettingNotFoundException} instead of \InvalidArgumentException
+	 */
+	public function getSettingById(string $id): ActivitySettings;
+
+	/**
+	 * @param string $type
+	 * @param int $id
+	 * @since 8.2.0
+	 */
+	public function setFormattingObject(string $type, int $id): void;
+
+	/**
+	 * @return bool
+	 * @since 8.2.0
+	 */
+	public function isFormattingFilteredObject(): bool;
+
+	/**
+	 * @param bool $status Set to true, when parsing events should not use SVG icons
+	 * @since 12.0.1
+	 */
+	public function setRequirePNG(bool $status): void;
+
+	/**
+	 * @return bool
+	 * @since 12.0.1
+	 */
+	public function getRequirePNG(): bool;
+
+	/**
+	 * Set the user we need to use
+	 *
+	 * @param string|null $currentUserId
+	 * @since 9.0.1
+	 */
+	public function setCurrentUserId(?string $currentUserId = null): void;
+
+	/**
+	 * Get the user we need to use
+	 *
+	 * Either the user is logged in, or we try to get it from the token
+	 *
+	 * @return string
+	 * @throws \UnexpectedValueException If the token is invalid, does not exist or is not unique
+	 * @since 8.1.0
+	 */
+	public function getCurrentUserId(): string;
+}
diff --git a/lib/public/Activity/IProvider.php b/lib/public/Activity/IProvider.php
new file mode 100644
index 00000000000..dec4e7ade64
--- /dev/null
+++ b/lib/public/Activity/IProvider.php
@@ -0,0 +1,31 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2016 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCP\Activity;
+
+use OCP\Activity\Exceptions\UnknownActivityException;
+
+/**
+ * Interface IProvider
+ *
+ * @since 11.0.0
+ */
+interface IProvider {
+	/**
+	 * @param string $language The language which should be used for translating, e.g. "en"
+	 * @param IEvent $event The current event which should be parsed
+	 * @param IEvent|null $previousEvent A potential previous event which you can combine with the current one.
+	 *                                   To do so, simply use setChildEvent($previousEvent) after setting the
+	 *                                   combined subject on the current event.
+	 * @return IEvent
+	 * @throws UnknownActivityException Should be thrown if your provider does not know this event
+	 * @since 11.0.0
+	 * @since 30.0.0 Providers should throw {@see UnknownActivityException} instead of \InvalidArgumentException
+	 *   when they did not handle the event. Throwing \InvalidArgumentException directly is deprecated and will
+	 *   be logged as an error in Nextcloud 39.
+	 */
+	public function parse($language, IEvent $event, ?IEvent $previousEvent = null);
+}
diff --git a/lib/public/Activity/ISetting.php b/lib/public/Activity/ISetting.php
new file mode 100644
index 00000000000..1304ab8c658
--- /dev/null
+++ b/lib/public/Activity/ISetting.php
@@ -0,0 +1,58 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2016 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCP\Activity;
+
+/**
+ * Interface ISetting
+ *
+ * @since 11.0.0
+ */
+interface ISetting {
+	/**
+	 * @return string Lowercase a-z and underscore only identifier
+	 * @since 11.0.0
+	 */
+	public function getIdentifier();
+
+	/**
+	 * @return string A translated string
+	 * @since 11.0.0
+	 */
+	public function getName();
+
+	/**
+	 * @return int whether the filter should be rather on the top or bottom of
+	 *             the admin section. The filters are arranged in ascending order of the
+	 *             priority values. It is required to return a value between 0 and 100.
+	 * @since 11.0.0
+	 */
+	public function getPriority();
+
+	/**
+	 * @return bool True when the option can be changed for the stream
+	 * @since 11.0.0
+	 */
+	public function canChangeStream();
+
+	/**
+	 * @return bool True when the option can be changed for the stream
+	 * @since 11.0.0
+	 */
+	public function isDefaultEnabledStream();
+
+	/**
+	 * @return bool True when the option can be changed for the mail
+	 * @since 11.0.0
+	 */
+	public function canChangeMail();
+
+	/**
+	 * @return bool True when the option can be changed for the stream
+	 * @since 11.0.0
+	 */
+	public function isDefaultEnabledMail();
+}