bash prompt with terraform workspace and git info

bash-prompt.sh

#!/bin/bash

if [[ ! -f $(brew --prefix)/opt/bash-git-prompt/share/gitprompt.sh ]]; then
  echo "installing first time bash-git-prompt"
  brew install bash-git-prompt
fi

if [[ -f $(brew --prefix)/opt/bash-git-prompt/share/gitprompt.sh ]]; then
  __GIT_PROMPT_DIR=$(brew --prefix)/opt/bash-git-prompt/share

  # configs
  # see https://github.com/magicmonty/bash-git-prompt#all-configs-for-bashrc
  GIT_PROMPT_ONLY_IN_REPO=1
  GIT_PROMPT_THEME=Solarized
  GIT_PROMPT_SHOW_UPSTREAM=1

  function prompt_callback() {
    # combine with terraform
    if command -v terraform >/dev/null && [ -d .terraform ]; then
      echo " [\[\e[1m\]workspace\e[0m:$(terraform workspace show 2>/dev/null || echo "<error>")]"
    fi
  }

  source "$(brew --prefix)/opt/bash-git-prompt/share/gitprompt.sh"
fi

# terraform workspace
if command -v terraform >/dev/null; then

  function terraform_prompt() {
    if [ -d .terraform ]; then
      # consider git-prompt
      if type -t git_prompt_config >/dev/null; then
        repo=$(git rev-parse --show-toplevel 2>/dev/null)
        if [[ -e $repo ]]; then
          # inside of git repository and with git-prompt we do nothing
          return
        fi
      fi

      # save old prompt
      if [[ -z $OLD_PS1 ]]; then
        OLD_PS1=${PS1}
      fi

      PS1='\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\e[38;5;99m\]\[\e[1m\]\n\[\033[1;34m\]$(date +%H:%M)\[\033[0;0m\] [workspace:$(terraform workspace show 2>/dev/null || echo "<error>")]\e[0m \$ '
    else
      # recover old prompt
      if [[ -n $OLD_PS1 ]]; then
        PS1=${OLD_PS1}
      fi
    fi
  }

  PROMPT_COMMAND="terraform_prompt; $PROMPT_COMMAND"
fi