main() {
  # Use colors, but only if connected to a terminal, and that terminal
  # supports them.
  if which tput >/dev/null 2>&1; then
    ncolors=$(tput colors)
  fi
  if [ -t 1 ] && [ -n "${ncolors}" ] && [ "${ncolors}" -ge 8 ]; then
    red="$(tput setaf 1)"
    green="$(tput setaf 2)"
    yellow="$(tput setaf 3)"
    blue="$(tput setaf 4)"
    bold="$(tput bold)"
    normal="$(tput sgr0)"
  else
    red=""
    green=""
    yellow=""
    blue=""
    bold=""
    normal=""
  fi

  # Only enable exit-on-error after the non-critical colorization stuff,
  # which may fail on systems lacking tput or terminfo
  set -e

  # Yes or no function
  yesno() {
    printf "${*} "
    read answer
    if printf "${answer}\n" | grep -iq "^y"; then
        return 0
    else
        return 1
    fi;
  }

  # Check if `zsh` exists, or if `zsh` isn't too old
  if [ ! "$(grep "/zsh$" "/etc/shells")" ] || \
    env zsh -c "autoload -Uz 'is-at-least'; ! is-at-least 5.2"; then
    yesno "Do you want the installer to automatically install 'zsh'?"
    # try installing from 'brew' (Mac)
    if hash "brew" 2>/dev/null; then
      brew install "zsh" >/dev/null 2>&1
      printf "${yellow}Installing zsh via Homebrew.. ${normal}\n"
    # try installing from 'apt-get' (Debian/Ubuntu)
    elif hash "apt-get" 2>/dev/null; then
      apt-get install "zsh" >/dev/null 2>&1
    # try installing from 'dnf' (Fedora)
    elif hash "dnf" 2>/dev/null; then
      dnf install "zsh" >/dev/null 2>&1
    # try installing from 'pacman' (Arch)
    elif hash "pacman" 2>/dev/null; then
      pacman -S "zsh" >/dev/null 2>&1
    else
      printf "${red}Error: 'zsh' isn't available.. ${blue}please install manually!${normal}\n"
      return 1
    fi
  fi

  # Check if Zim is already installed
  if [ -e "${ZDOTDIR:-${HOME}}/.zimrc" ]; then
    printf "${red}Error: You already have Zim installed!${normal}\n";
    return 1
  fi

  # Check if other frameworks are installed
  if [ -d "${HOME}/.oh-my-zsh" ]; then
    mv "${HOME}/.oh-my-zsh" "${HOME}/.oh-my-zsh_zimbackup"
    printf "${yellow}Oh-My-Zsh detected and backed up to\
     ${HOME}/.oh-my-zsh_zimbackup${normal}\n"
    printf "${blue}This is done to prevent framework conflicts.${normal}\n"
  elif [ -d "${HOME}/.zplug" ]; then
    mv "${HOME}/.zplug" "${HOME}/.zplug_zimbackup"
    printf "${yellow}Zplug detected and backed up to\
     ${HOME}/.zplug_zimbackup${normal}\n"
    printf "${blue}This is done to prevent framework conflicts.${normal}\n"
  elif [ -d "${HOME}/.zprezto" ]; then
    mv "${HOME}/.zprezto" "${HOME}/.zprezto_zimbackup"
    printf "${yellow}Prezto detected and backed up to\
     ${HOME}/.zprezto_zimbackup${normal}\n"
    printf "${blue}This is done to prevent framework conflicts.${normal}\n"
  fi

  # Prevent the cloned repository from having insecure permissions.
  umask g-w,o-w

  # The Windows (MSYS) Git is not compatible with normal use on cygwin
  if [ "${OSTYPE}" = "cygwin" ]; then
    if git --version | grep msysgit >/dev/null; then
      printf "${red}Error: Windows/MSYS Git is not supported on Cygwin${normal}\n"
      printf "${red}Error: Make sure the Cygwin git package is installed and is first on the path${normal}\n"
      return 1
    fi
  fi

  # Back-up old zsh dotfiles
  if [ -e "${HOME}/.zshrc" ]; then
    printf "${yellow}Found ${HOME}/.zshrc! ${blue}Backing up to ${HOME}/.zshrc_zimbackup.${normal}\n"
    mv "${HOME}/.zshrc" "${HOME}/.zshrc_zimbackup"
  fi
  if [ -e "${HOME}/.zlogin" ]; then
    printf "${yellow}Found ${HOME}/.zlogin!$ ${blue}Backing up to ${HOME}/.zlogin_zimbackup${normal}\n"
    mv "${HOME}/.zlogin" "${HOME}/.zlogin_zimbackup"
  fi

  # Place template files in ~/
  cp -a "${HOME}/.zim/templates/" "${HOME}/"

  # If this user's login shell is not already "zsh", attempt to switch
  if [ ! "$(expr "${SHELL}" : '.*/\(.*\)')" = "zsh" ]; then
    # Auto-change shell if platform provides "chsh" command
    if hash chsh >/dev/null 2>&1; then
      printf "${blue}Changing your default shell to zsh!${normal}\n"
      chsh -s $(grep "/zsh$" "/etc/shells" | tail -1)
    # If not, suggest user do so manually.
    else
      printf "${yellow}I can't change your shell automatically because this system does not have chsh.${normal}\n"
      printf "${yellow}Please manually change your default shell to zsh!${normal}\n"
    fi
  fi

  Z="${red}Z${green}"
  printf "${green}   ______    _       _____ __  __                              _               ${normal}\n"
  printf "${green}  |$Z$Z$Z$Z$Z/   | |     |$Z$Z$Z$Z$Z|$Z$Z\/$Z$Z|                            | |${normal}\n"
  printf "${green}     /$Z/ ___| |__     |$Z| |$Z\\$Z$Z/$Z|_ __  _ __ _____   _____  __| |       ${normal}\n"
  printf "${green}    /$Z/ / __| '_ \    |$Z| |$Z|\/|$Z| '_ \| '__/ _ \ \ / / _ \/ _\` |          ${normal}\n"
  printf "${green}   /$Z/__\__ | | | |  _|$Z|_|$Z|  |$Z| |_) | | | (_) \ V |  __| (_| |          ${normal}\n"
  printf "${green}  /$Z$Z$Z$Z$Z|___|_| |_| |$Z$Z$Z$Z$Z|$Z|  |$Z| .__/|_|  \___/ \_/ \___|\__,_|  ${normal}\n"
  printf "${green}                                 | |                                           ${normal}\n"
  printf "${green}                                 |_|                                           ${normal}\n"
  unset Z

  # For archival purposes
  #   ______      _       _____  __  __                                    _
  #  |___  /     | |     |_   _||  \/  |                                  | |
  #     / /  ___ | |__     | |  | \  / | _ __   _ __  ___ __   __ ___   __| |
  #    / /  / __|| '_ \    | |  | |\/| || '_ \ | '__|/ _ \\ \ / // _ \ / _` |
  #   / /__ \__ \| | | |  _| |_ | |  | || |_) || |  | (_) |\ V /|  __/| (_| |
  #  /_____||___/|_| |_| |_____||_|  |_|| .__/ |_|   \___/  \_/  \___| \__,_|
  #                                      | |
  #                                      |_|

  # Remind user to copy back old settings
  if [ -f "${HOME}/.zshrc_zimbackup" ] || [ -L "${HOME}/.zshrc_zimbackup" ]; then
    printf "${yellow}Please inspect ${HOME}/.zshrc_zimbackup and copy over${normal}\n"
    printf "${yellow}wanted settings to ${HOME}/.zshrc${normal}\n"
  fi
  if [ -f "${HOME}/.zlogin_zimbackup" ] || [ -L "${HOME}/.zlogin_zimbackup" ]; then
    printf "${yellow}Please inspect ${HOME}/.zlogin_zimbackup and copy over${normal}\n"
    printf "${yellow}wanted settings to ${HOME}/.zlogin${normal}\n"
  fi

  # Load zsh
  env zsh
}

main