How to get prefix for section numbering in Table of Contents using tocloft

Im trying to make a customized Table of Content. The section numbering in the document is as follows:

101. Title of section. (Underline, in running text, with the first letter capitalized)

In table of Contents, I want it to be under the respective chapter as:

SECTION 1 - Title of Section

I want to set \thesection in a manner that complies with the above requirement.

\documentclass{book}
\usepackage[total={6.5in,8.75in},top=1in, left=2.5cm,right=2.5cm]{geometry}

\usepackage{calc}
\usepackage{float}


\usepackage{ulem} 
\useunder{\uline}{\ulined}{}
\renewcommand{\ULdepth}{1.6pt} 
\usepackage[T1]{fontenc}
\usepackage{listings}
\usepackage{chngcntr}
\usepackage{tocloft}
\usepackage{url}
\usepackage{titlesec}   
\usepackage{titletoc}  
\usepackage{alphalph}
\usepackage{chappg}
\usepackage{refcount}
\usepackage{lastpage}



\pagenumbering{roman} 

\newcommand{\partfnt}{\fontsize{12}{12}}
\newcommand{\chapfnt}{\fontsize{12}{12}}
\newcommand{\secfnt}{\fontsize{12}{12}}
\newcommand{\ssecfnt}{\fontsize{12}{12}}
 

 
\titleformat{\part}{\centering\normalsize \partfnt}{\underline{\Huge\ PART \thepart - }}{0em}{\Huge \uppercase \uline}


\makeatletter
\def\@makechapterhead#1{%
    \vspace*{0}% Space above number
    {\parindent \z@  \normalfont
    \interlinepenalty\@M
    \normalsize\centering \underline{\normalsize\ CHAPTER \thechapter}%
    \par\vspace{12pt}% Space between number and title
    \centering \underline{\MakeUppercase{#1}}%
    \par\vspace{12pt}% Space between title and text
}}
\makeatother

 

\titleformat{\section}{\centering\normalsize \secfnt}{\underline{\normalsize\ SECTION \thesection - }}{0em}{\uppercase \uline}

\titleformat{\subsection}{\normalfont \ssecfnt}{\thesubsection}{1em}{\uppercase \uline} %FINAL for unbold subsection
 


 
\renewcommand\thesection{\arabic{section}}

\renewcommand\thesubsection{\ifnum\value{subsection}<10 010\fi\arabic{subsection}.}

 
\newlength{\mylen} % a "scratch" length
\settowidth{\mylen}{\normalfont \cftsecpresnum\cftsecaftersnum} % extra space
\addtolength{\cftsecnumwidth}{\mylen} % add the extra space

\begin{document}

\renewcommand\contentsname{\underline{CONTENTS}}
\renewcommand{\cfttoctitlefont}{\hfill\normalsize\bfseries} 
\renewcommand{\cftaftertoctitle}{\hfill}

\setcounter{tocdepth}{1}

 
\renewcommand{\cftpartfont}{\uppercase \normalfont} % set part font
\renewcommand{\cftpartpagefont}{\normalfont}
\renewcommand{\cftpartdotsep}{100000000000} % adds dots between part name and page number but setting large value will remove dots
\renewcommand{\cftpartleader}{\cftdotfill{\cftpartdotsep}}
\renewcommand{\cftpartafterpnum}{\cftparfillskip} % add space after page number if needed
\renewcommand{\cftpartpresnum}{PART}  
\renewcommand{\cftpartaftersnum}{-} 
\renewcommand{\cftpartaftersnumb}{\\} 
\renewcommand{\cftbeforepartskip}{12}
 
 



\renewcommand{\cftchapfont}{\normalfont}  
\renewcommand{\cftchappagefont}{\normalfont}
\renewcommand{\cftchapdotsep}{100000000000}   
\renewcommand{\cftchapleader}{\cftdotfill{\cftchapdotsep}}
 
\renewcommand{\cftchapaftersnum}{.}  
\renewcommand{\cftchapaftersnumb}{\\} 
\renewcommand{\cftbeforechapskip}{12}
\renewcommand{\cftchapnumwidth}{3em}


\renewcommand{\cftsecfont}{\normalfont}
\renewcommand{\cftsecpagefont}{\normalfont}
\renewcommand{\cftsecdotsep}{100000000000}
\renewcommand{\cftsecleader}{\normalfont\cftdotfill{\cftsecdotsep}}  
 
\renewcommand{\cftsecpresnum}{SECTION\ }   
\renewcommand{\cftsecaftersnum}{\ -\ } 
\renewcommand{\cftsecaftersnumb}{\\}
\renewcommand{\cftsecindent}{5em}
 



 


\tableofcontents


\addtocontents{toc}{\textbf{CHAPTER}\hfill\textbf{SUBJECT}\hfill\textbf{PAGE NO}\par}
\addcontentsline{toc}{chapter}{\hspace{5em} \normalfont Promulgation}
\addcontentsline{toc}{chapter}{\hspace{5em} \normalfont Improvement}


\newpage
    




\clearpage


 
\renewcommand\thepage{\arabic{chapter}-\arabic{page}}


 

 
\part{General}
 

\setcounter{page}{1} 
\chapter{Chapter}
ABCD

\section{somthing}
something
\subsection{Something}
Something

\part{Special}

\setcounter{page}{1}
\chapter{Chapter}
ABCD
\section{somthing}
something
\subsection{Something}
Something

 
\end{document}