I would like to center PART and wrap the subsubsection in one line in TOC, with proper indentation (matching with section or subsection or chapter). Please see the image. Attached is the sample code too. Thank you very much.

\documentclass[12pt,bothside]{book}
\usepackage[titles]{tocloft}%
\renewcommand{\cftchapleader}{~\cftdotfill{5}}
\setcounter{secnumdepth}{0}
\setcounter{tocdepth}{3}
% to center part
\renewcommand{\cftpartfont}{\hfill\Large\bfseries}
\renewcommand{\cftpartaftersnum}{\hfill}
\addtocontents{toc}{\cftpagenumbersoff{part}}
%wrap TOC contents
\usepackage{titletoc}
\titlecontents*{subsubsection}% <section>
[1.5em]% <left>
{\scriptsize}% <above-code>
{}% <numbered-entry-format>
{}% <numberless-entry-format>
{,\ \thecontentspage}% <filler-page-format>
[\ - \ ]% <separator>
[\\]% <end>
\begin{document}
\frontmatter
\tableofcontents
\mainmatter
\part{Part 1}
\chapter{Chapter1}
\section{Section 1}
\subsubsection{Subsubsection 1}
\subsubsection{Subsubsection 2}
\part{Part 2}
\chapter{Chapter1}
\section{Section 1}
\subsection{Subection 1}
\subsubsection{Subsubsection 1}
\subsubsection{Subsubsection 2}
\end{document}
