bash: add a custom prompt with git awareness

.mgr_config/.bashrc

@@ -11,6 +11,76 @@ alias highlight='grep -U999999 --color=always'
 
 export PATH=$PATH:$HOME/.mgr_config/bin
 
+FG_BLK="$(tput setaf 0)"
+FG_RED="$(tput setaf 1)"
+FG_GRN="$(tput setaf 2)"
+FG_YEL="$(tput setaf 3)"
+FG_BLU="$(tput setaf 4)"
+FG_MGN="$(tput setaf 5)"
+FG_CYN="$(tput setaf 6)"
+FG_WHT="$(tput setaf 7)"
+FG_DEF="$(tput setaf 9)"
+
+BG_BLK="$(tput setab 0)"
+BG_RED="$(tput setab 1)"
+BG_GRN="$(tput setab 2)"
+BG_YEL="$(tput setab 3)"
+BG_BLU="$(tput setab 4)"
+BG_MGN="$(tput setab 5)"
+BG_CYN="$(tput setab 6)"
+BG_WHT="$(tput setab 7)"
+BG_DEF="$(tput setab 9)"
+
+BOLD="$(tput bold)"
+
+RST=$(tput sgr0)
+
+git_root() {
+  git rev-parse --show-toplevel 2> /dev/null
+}
+
+prompt_function() {
+  prompt=""
+
+  HOST_COLOR_ID=$(( "16#$(echo tls-proxy | md5sum | cut -f1 -d' ')" % 7 + 1)) # [1, 7]
+  HOST_COLOR="${RST}$(tput setaf $HOST_COLOR_ID)"
+  GIT_COLOR="${RST}${FG_CYN}"
+  DIR_COLOR="${RST}${FG_YEL}"
+  WARN_COLOR="${RST}${BOLD}${FG_RED}"
+
+  if [[ $INSIDE_EMACS ]]; then
+    prompt+=""
+  fi
+
+  if [[ "$(whoami)" == root ]]; then
+      prompt+="${WARN_COLOR}"
+  else
+      prompt+="${HOST_COLOR}"
+  fi
+  prompt+="$(whoami)@$(hostname)${RST}:"
+  if root=$(git_root); then
+      # If in a git repository, only print the path relative to the repo root
+      path=$(realpath --relative-to=$root $PWD)
+      ref=$(git symbolic-ref --short -q HEAD)
+      if [[ $ref == "" ]]; then
+          ref="${WARN_COLOR}detached${GIT_COLOR}"
+      fi
+      dirty=$(git diff-index --quiet HEAD)
+      if [[ $path == . ]]; then
+          path=""
+      fi
+      prompt+="${GIT_COLOR}[$(basename $root)@${ref}:${DIR_COLOR}${path}${fg}${GIT_COLOR}]${RST}"
+  else
+      # If not in a git repo, print the full path
+      prompt+="${DIR_COLOR}[$(dirs)]${RST}"
+  fi
+
+  echo "$prompt\$ "
+}
+
+PS1="\$(prompt_function)"
+
+
 if [[ -z "$INSIDE_EMACS" ]]; then
    EMACS="emacsclient -a="" -c"
    alias emacs="$EMACS"