BP_Messages_Thread::populate( int $thread_id, string $order = 'DESC', array $args = array() )

	public function populate( $thread_id = 0, $order = 'DESC', $args = array() ) {

		if ( 'ASC' !== $order || 'DESC' !== $order ) {
			$order = 'DESC';
		}

		$user_id =
			bp_displayed_user_id() ?
			bp_displayed_user_id() :
			bp_loggedin_user_id();

		// Merge $args with our defaults.
		$r = wp_parse_args( $args, array(
			'user_id'           => $user_id,
			'update_meta_cache' => true,
			'per_page'          => apply_filters('bp_messages_default_per_page', 10),
			'before'   => null
		) );

		$this->messages_order   = $order;
		$this->messages_perpage = $r['per_page'];
		$this->messages_before  = $r['before'];
		$this->thread_id        = (int) $thread_id;

		// get the last message deleted for the thread
		static::get_user_last_deleted_message( $this->thread_id );

		// Get messages for thread.
		$this->messages       = self::get_messages( $this->thread_id, $this->messages_before, $this->messages_perpage, $this->messages_order );
		$this->last_message   = self::get_last_message( $this->thread_id );
		$this->total_messages = self::get_messages_count( $this->thread_id );

		if ( empty( $this->messages ) || is_wp_error( $this->messages ) ) {
			return false;
		}

		$this->last_message_id      = $this->last_message->id;
		$this->last_message_date    = $this->last_message->date_sent;
		$this->last_sender_id       = $this->last_message->sender_id;
		$this->last_message_subject = $this->last_message->subject;
		$this->last_message_content = $this->last_message->message;

		$this->first_message_date   = self::get_messages_started( $this->thread_id );;

		foreach ( (array) $this->messages as $key => $message ) {
			$this->sender_ids[ $message->sender_id ] = $message->sender_id;
		}

		// Fetch the recipients.
		$this->recipients = $this->get_recipients();

		// Get the unread count for the logged in user.
		if ( isset( $this->recipients[ $r['user_id'] ] ) ) {
			$this->unread_count = $this->recipients[ $r['user_id'] ]->unread_count;
		}

		// Grab all message meta.
		if ( true === (bool) $r['update_meta_cache'] ) {
			bp_messages_update_meta_cache( wp_list_pluck( $this->messages, 'id' ) );
		}

		/**
		 * Fires after a BP_Messages_Thread object has been populated.
		 *
		 * @since BuddyPress 2.2.0
		 *
		 * @param BP_Messages_Thread $this Message thread object.
		 */
		do_action( 'bp_messages_thread_post_populate', $this );
	}