#!/bin/bash

set -e

show_usage() {
  echo "usage: $0 [-h] [-y]"
}

show_help() {
  show_usage
  echo
  echo "Bootstrap a Debian based distribution with:"
  echo
  echo "* update apt cache"
  echo "* upgrade apt packages"
  echo "* git - from apt"
  echo "* python - from apt"
  echo "* python-pip - from apt"
  echo "* virtualenv - from pip"
  echo "* SSH key - from ssh-keygen"
  echo "* GitHub public key - with SSH key"
  echo "* GitLab public key - with SSH key"
  echo "* BitBucket Cloud public key - with SSH key"
  echo "* Gogs Cloud public key - with SSH key"
  echo "* conduit - configuration manager"
  echo
  echo "If any already exist they will not be reinstalled."
  echo
  echo "optional arguments:"
  echo "        -h              show this help message and exit"
  echo "        -y              assume yes when prompted"
}

yes=0

while getopts 'hy' opt; do
  case $opt in
    h) show_help; exit 0 ;;
    y) yes=1 ;;
    *) show_usage; exit 1 ;;
  esac
done

missing() {
  which $1 &> /dev/null && return 1 || return 0
}

agree() {
  local check=^[Nn]$
  [ $yes -eq 1 ] && [[ ! "$2" =~ $check ]] && return 0
  [[ "$2" =~ $check ]] && local default="[y/N]" || local default="[Y/n]"
  read -p "$1 $default? " answer
  case "$answer" in
    y|Y|yes) return 0 ;;
    n|N|no) return 1 ;;
    '') [[ "$2" =~ $check ]] && return 1 || return 0 ;;
    *) echo "invalid input: $answer" && return `agree "$1"` ;;
  esac
}

apt_install() {
  sudo apt-get install --yes --install-recommends $1 > /dev/null
}

pip_install() {
  pip3 install --user $1 > /dev/null
}

export PATH=~/.local/bin:$PATH

missing git && agree "Install git" && apt_install git

if missing python; then
  agree "Intsall python-is-python3" && apt_install python-is-python3
fi

if missing pip3; then
  agree "Install python-pip" && apt_install python3-pip
fi

if missing virtualenv; then
  agree "Install python3-virtualenv" && apt_install python3-virtualenv
fi

if [ ! -f ~/.ssh/id_rsa ] && agree "Generate SSH key"; then
  read -rp "SSH email: " email
  [ ! -d ~/.ssh ] && mkdir -p ~/.ssh
  ssh-keygen -t ed25519 -C "$email" -N "" -f ~/.ssh/id_rsa
fi

missing conduit && agree "Install ansible" && \
  pip_install ansible

echo "To use installed pip packages update your PATH:"
echo 'export PATH=~/.local/bin:$PATH'

[ -f $0 ] && agree "Remove $0" "N" && rm $0 || exit 0