#!/bin/bash

set -e

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

show_help() {
  show_usage
  echo
  echo "Bootstrap a macOS instance with:"
  echo
  echo "* Xcode command line developer tools"
  echo "* Homebrew - package manager"
  echo "* python - from Homebrew"
  echo "* virtualenv - from pip"
  echo "* SSH key - from ssh-keygen"
  echo "* GitHub 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
}

brew_install() {
  brew install $1 > /dev/null
}

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

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

if ! xcode-select --print-path &> /dev/null; then
  agree "Install Xcode command line developer tools" && xcode-select --install
fi

missing brew && agree "Intalll Homebrew" && /usr/bin/ruby -e \
  "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

agree "Update Homebrew packages" && brew update > /dev/null

if missing /usr/local/bin/python2 && agree "Install Homebrew python"; then
  brew_install python
  export PATH=/usr/local/opt/python/libexec/bin:$PATH
  echo "To use Homebrew python update your PATH:"
  echo 'export PATH=/usr/local/opt/python/libexec/bin:$PATH'
fi

missing virtualenv && agree "Install virtualenv" && pip_install virtualenv

if [ ! -f ~/.ssh/id_rsa ] && agree "Generate SSH key"; then
  read -rp "SSH email: " email
  [ ! -d ~/.ssh ] && mkdir -p ~/.ssh
  ssh-keygen -t rsa -b 4096 -C "$email" -N "" -f ~/.ssh/id_rsa
fi

if ! missing virtualenv && agree "GitHub public key"; then
  env=$(mktemp -d)
  virtualenv $env &> /dev/null
  source $env/bin/activate
  pip install githubpy &> /dev/null
  python <(cat << EOF
from __future__ import print_function
from os import environ
from os.path import join
from getpass import getpass
from github import GitHub


def getinput(prompt):
    try:
        return raw_input(prompt)
    except NameError:
        return input(prompt)


def main():
    username = getinput('GitHub username: ')
    password = getpass('GitHub password: ')
    github = GitHub(username=username, password=password)
    keys = github.user.keys().get()
    id_rsa_pub_path = join(environ['HOME'], '.ssh', 'id_rsa.pub')
    with open(id_rsa_pub_path, 'r') as id_rsa_pub_file:
        local_key = id_rsa_pub_file.read()
        for key in keys:
            if local_key.startswith(key['key']):
                print('Satisfied: GitHub public key')
                exit(0)
        title = getinput('GitHub key name: ')
        github.user.keys().post(title=title, key=local_key)
        print('Installed: GitHub public key')
        exit(0)


if __name__ == '__main__':
    try:
        main()
    except KeyboardInterrupt:
        exit(130)

EOF
  )
  deactivate
  rm -r $env
fi

# TODO: Gogs SSH key

# Prompt user to setup other SSH key recipients
if [ -f ~/.ssh/id_rsa.pub ]; then
  echo '----------------------------------------------------------------------'
  cat ~/.ssh/id_rsa.pub
  echo '----------------------------------------------------------------------'
  read -rp "Set other SSH key recipients, press ENTER to continue: "
fi

! missing pip && missing conduit && agree "Install conduit" && \
  pip_install git+ssh://git@github.com/kbenzie/conduit.git

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

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