Latex table of contents customization

Question

I am trying to modify my table of content and here is some part of my code

\renewcommand{\contentsname }{ TABLE OF CONTENTS}

\tableofcontents
\addtocontents{toc}{~\hfill  Page\par}
\let\LaTeXStandardTableOfContents\tableofcontents

\renewcommand{\tableofcontents}{%
\begingroup%
\renewcommand{\bfseries}{\relax}%
\LaTeXStandardTableOfContents%
\endgroup%
}%

The output is

What I want is

There are two differences.

1) TABLE OF CONTENTS is not bold.

2) The word CHAPTER 1 does not appear above INTRODUCTION

How could I fix these?

Answer 1

Here is a solution with titletoc:

\documentclass[11pt, english]{book}
\usepackage[utf8]{inputenc}
\usepackage{babel} 
\usepackage{fourier, erewhon, cabin}
\usepackage[showframe]{geometry}
\usepackage[clearempty, pagestyles]{titlesec}
\usepackage{titletoc}
\usepackage{lipsum}

\titleformat{\chapter}[display]%
{\null\vskip1em\sffamily\bfseries\Large\filleft}{Chapter \thechapter}{2ex}{\LARGE}
\titleformat{name = \chapter, numberless}[block]%
{\null\vskip1em\sffamily\bfseries\Large\filleft}{}{0em}{\LARGE}
\titlespacing*{\chapter}{0em}{-2\baselineskip}{4\baselineskip}

\addto\captionsenglish{\renewcommand*\contentsname{Table of Contents}}

\titlecontents{chapter}
[0em] %
{\medskip}
{\contentslabel[\rlap{\MakeUppercase\chaptername~\thecontentslabel}]{0em}\endgraf\MakeUppercase}% for numbered chapters
{\MakeUppercase} % for unnumbered chapters
{\hfill\contentspage}[\smallskip]

\titlecontents{section}
 [3em]%
 {\medskip}
 {\thecontentslabel\enspace}% for numbered sections
 {\hspace*{1.82em}} for unnumbered sections
 {\hfill\contentspage}%]

\begin{document}

\frontmatter
    \tableofcontents

\listoffigures \addcontentsline{toc}{chapter}{\listfigurename}
\listoftables \addcontentsline{toc}{chapter}{\listtablename}

\mainmatter
    \chapter{Introduction}
    \lipsum[1]
    \section{Clinical Trials}

   \lipsum[2-5]
\section*{A test section}\addcontentsline{toc}{section}{A test section}
\lipsum[6-10]
    \chapter{Chapter Two}
    Content

\end{document}