bp_dd_import_users_messages()

function bp_dd_import_users_messages() {
	$messages            = array();
	$random_thread_reply = array();

	if ( ! bp_is_active( 'messages' ) ) {
		return $messages;
	}

	/** @var $messages_subjects array */
	/** @var $messages_content array */
	require( BP_DEFAULT_DATA_DIR . 'data/messages.php' );

	$users_data = require( BP_DEFAULT_DATA_DIR . 'data/users.php' );
	$users_data = wp_list_pluck( $users_data, 'login', 'refer_id' );
	foreach ( $messages as $message ) {
		$user_object = get_user_by( 'login', $users_data[ $message['sender_refer_id'] ] );

		$user_id            = empty( $user_object->ID ) ? bp_dd_get_random_users_ids( 1, 'string' ) : $user_object->ID;
		$recipients_numbers = empty( $message['recipients'] ) ? 1 : $message['recipients'];
		$recipients         = bp_dd_get_random_users_ids( absint( $recipients_numbers ), 'array' );

		$thread_reply = empty( $message['thread_reply'] ) ? 1 : $message['thread_reply'];

		$message_id = messages_new_message( array(
			'sender_id'  => $user_id,
			'recipients' => $recipients,
			'subject'    => $message['content'],
			'content'    => $message['content'],
			'date_sent'  => bp_dd_get_random_date( 29, 16 ),
		) );

		$messages[] = $message_id;

		$all_recipients = array_merge( $recipients, (array) $user_id );

		// first level messages
		for ( $i = 0; $i <= $thread_reply; $i ++ ) {
			$replying_sender_id     = $all_recipients[ array_rand( $all_recipients ) ];
			$replying_recipients_id = array_diff( $all_recipients, (array) $replying_sender_id );

			$messages[] = messages_new_message( array(
				'sender_id'  => $replying_sender_id,
				'recipients' => $replying_recipients_id,
				'thread_id'  => $message_id,
				'subject'    => $message['content'],
				'content'    => $random_thread_reply[ array_rand( $random_thread_reply ) ],
				'date_sent'  => bp_dd_get_random_date( 15, 1 ),
			) );
		}
	}

	if ( ! empty( $messages ) ) {
		/** @noinspection PhpParamsInspection */
		bp_update_option( 'bp_dd_imported_user_messages_ids', $messages );
	}

	return $messages;
}