feat(essembeh): update theme with new features (#9595)

- single line
- quite simple by default: user@host:$PWD
- green for local shell as non root
- red for ssh shell as non root
- magenta for root sessions
- prefix with remote address for ssh shells
- prefix to detect docker containers or chroot
- git plugin to display current branch and status

themes/essembeh.zsh-theme

-# Theme with full path names and hostname
-# Handy if you work on different servers all the time;
-
-local return_code="%(?..%{$fg_bold[red]%}%? ↵%{$reset_color%})"
-
-function my_git_prompt_info() {
-	ref=$(git symbolic-ref HEAD 2> /dev/null) || return
-	GIT_STATUS=$(git_prompt_status)
-	[[ -n $GIT_STATUS ]] && GIT_STATUS=" $GIT_STATUS"
-	echo "$ZSH_THEME_GIT_PROMPT_PREFIX${ref#refs/heads/}$GIT_STATUS$ZSH_THEME_GIT_PROMPT_SUFFIX"
-}
-
-# Colored prompt
-ZSH_THEME_COLOR_USER="green" 
-ZSH_THEME_COLOR_HOST="green" 
-ZSH_THEME_COLOR_PWD="yellow" 
-test -n "$SSH_CONNECTION" && ZSH_THEME_COLOR_USER="red" && ZSH_THEME_COLOR_HOST="red"
-test `id -u` = 0 && ZSH_THEME_COLOR_USER="magenta" && ZSH_THEME_COLOR_HOST="magenta"
-PROMPT='%{$fg_bold[$ZSH_THEME_COLOR_USER]%}%n@%{$fg_bold[$ZSH_THEME_COLOR_HOST]%}%M%{$reset_color%}:%{$fg_bold[$ZSH_THEME_COLOR_PWD]%}%~%{$reset_color%} $(my_git_prompt_info)%(!.#.$) '
-RPS1="${return_code}"
+# My custom theme:
+#   - single line
+#   - quite simple by default: user@host:$PWD
+#   - green for local shell as non root
+#   - red for ssh shell as non root
+#   - magenta for root sessions
+#   - prefix with remote address for ssh shells
+#   - prefix to detect docker containers or chroot
+#   - git plugin to display current branch and status
 
+# git plugin 
 ZSH_THEME_GIT_PROMPT_PREFIX="%{$fg[cyan]%}("
 ZSH_THEME_GIT_PROMPT_SUFFIX=") %{$reset_color%}"
 ZSH_THEME_GIT_PROMPT_UNTRACKED="%%"
@@ -28,3 +18,33 @@ ZSH_THEME_GIT_PROMPT_RENAMED="~"
 ZSH_THEME_GIT_PROMPT_DELETED="!"
 ZSH_THEME_GIT_PROMPT_UNMERGED="?"
 
+function zsh_essembeh_gitstatus {
+	ref=$(git symbolic-ref HEAD 2> /dev/null) || return
+	GIT_STATUS=$(git_prompt_status)
+	if [[ -n $GIT_STATUS ]]; then
+		GIT_STATUS=" $GIT_STATUS"
+	fi
+	echo "$ZSH_THEME_GIT_PROMPT_PREFIX${ref#refs/heads/}$GIT_STATUS$ZSH_THEME_GIT_PROMPT_SUFFIX"
+}
+
+# by default, use green for user@host and no prefix
+local ZSH_ESSEMBEH_COLOR="green"
+local ZSH_ESSEMBEH_PREFIX=""
+if [[ -n "$SSH_CONNECTION" ]]; then
+	# display the source address if connected via ssh
+	ZSH_ESSEMBEH_PREFIX="%{$fg[yellow]%}[$(echo $SSH_CONNECTION | awk '{print $1}')]%{$reset_color%} "
+	# use red color to highlight a remote connection
+	ZSH_ESSEMBEH_COLOR="red"
+elif [[ -r /etc/debian_chroot ]]; then 
+	# prefix prompt in case of chroot
+	ZSH_ESSEMBEH_PREFIX="%{$fg[yellow]%}[chroot:$(cat /etc/debian_chroot)]%{$reset_color%} "
+elif [[ -r /.dockerenv ]]; then
+	# also prefix prompt inside a docker contrainer
+	ZSH_ESSEMBEH_PREFIX="%{$fg[yellow]%}[docker]%{$reset_color%} "
+fi
+if [[ $UID = 0 ]]; then
+	# always use magenta for root sessions, even in ssh
+	ZSH_ESSEMBEH_COLOR="magenta"
+fi
+PROMPT='${ZSH_ESSEMBEH_PREFIX}%{$fg[$ZSH_ESSEMBEH_COLOR]%}%n@%M%{$reset_color%}:%{%B$fg[yellow]%}%~%{$reset_color%b%} $(zsh_essembeh_gitstatus)%(!.#.$) '
+RPROMPT="%(?..%{$fg[red]%}%?%{$reset_color%})"