#!/bin/bash

function ask_user {
  if [ "$(whoami)" != "root" ];
  then
    echo please execute this script as root!
    exit 2
  fi

  if [ ! \( -f /etc/debian_version -o -f /etc/arch-release \) ]
  then
    echo
    echo 'Your system is not supported.'
    exit 2
  elif ! pidof systemd >/dev/null
  then
    echo
    echo 'Your system does not run systemd. It is only partitially supported. '
    echo 'Do you want to continue? [y/N]'
    read CONTINUE
    if [ "$CONTINUE" == "y" ]
    then
      END_NOTICE="$END_NOTICE\nYou will have to write your own init-script or start the hopglass-server directly in \"/etc/rc.local\". \n DON'T RUN THE SERVER AS ROOT UNDER ANY CIRCUMSTANCES! \nThe command for starting the hopglass-server is \"su - hopglass -s /bin/bash -c 'node --harmony /opt/hopglass/server/hopglass-server.js [--config /path/to/config.json]'\"."
    else
      exit 2
    fi
  fi

  DONE=0
  while [ ! $DONE -eq 1 ]
  do
    echo
    echo "Where do you want to install the HopGlass Server? [/opt/hopglass]"
    read INSTALL_DIR
    INSTALL_DIR="${INSTALL_DIR:-/opt/hopglass}"
    PARENT_DIR="$(echo $INSTALL_DIR | sed 's;/$;;' | rev | cut -d'/' -f2- | rev)"
    if [ ! -d "$PARENT_DIR" ]
    then
      echo The parent directory $PARENT_DIRECTORY doesn\'t exist.
    elif [ -d "$INSTALL_DIR" ] && ! ls "$INSTALL_DIR" >/dev/null 2>&1
    then
      echo 'The specified directory already exists and is not empty. Do you want to continue? [y/N]'
      read CONTINUE
      if [ "$CONTINUE" == "y" ]
      then
        DONE=1
      fi
    else
      DONE=1
    fi
  done
}

function prereq {
  if test -f /etc/debian_version
  then
    ##########
    # Debian #
    ##########

    apt-get update
    apt-get install apt-transport-https curl git lsb-release -y

    #Install NodeJS from external repositories
    DISTRO=$(lsb_release -c -s)
    if [ "$DISTRO" == "stretch" ]
    then
      DISTRO="jessie"
    fi

    if curl -f "https://deb.nodesource.com/node_6.x/dists/$DISTRO/Release" >/dev/null
    then
      apt-get remove nodejs nodejs-legacy npm -y
      curl -s https://deb.nodesource.com/gpgkey/nodesource.gpg.key | apt-key add -
      echo "deb https://deb.nodesource.com/node_6.x $DISTRO main" > /etc/apt/sources.list.d/nodesource.list
      echo "deb-src https://deb.nodesource.com/node_6.x $DISTRO main" >> /etc/apt/sources.list.d/nodesource.list
      apt-get update
      apt-get install nodejs git -y
    else
      END_NOTICE="$END_NOTICE\nYour distribution is not supported by NodeJS. \nYou have to install a recent NodeJS version (>=4) manually. "
    fi

    adduser --system --home=$INSTALL_DIR --group hopglass
  elif test -f /etc/arch-release
  then
    #############
    # ArchLinux #
    #############

    #latest NodeJS is a available in the Arch repos
    pacman -Syy
    pacman -S nodejs npm git --noconfirm --needed

    useradd -Urm -s /usr/bin/nologin -d $INSTALL_DIR hopglass
  fi

  chmod 755 $INSTALL_DIR
  chown hopglass:hopglass $INSTALL_DIR
  rm -rf $INSTALL_DIR/server 2>/dev/null
}

function install {
  #Clone and install NodeJS libs
  su - hopglass --shell /bin/bash <<'EOF'
  git clone https://github.com/plumpudding/hopglass-server -b v0.1 server
  cd server
  npm install
  exit
EOF
#EOF can't be indented

  #Symlink systemd service and copy config file:
  #only for systemd-systems
  if pidof systemd >/dev/null
  then
    mkdir -p /etc/hopglass-server/default
    cp $INSTALL_DIR/server/config.json.example /etc/hopglass-server/default/config.json
    cp $INSTALL_DIR/server/hopglass-server@.service /lib/systemd/system/
    sed "s;/opt/hopglass;$INSTALL_DIR;g" -i /lib/systemd/system/hopglass-server@.service
    chown -R hopglass:hopglass /etc/hopglass-server

    END_NOTICE="$END_NOTICE\nStart the HopGlass Server using\n'# systemctl start hopglass-server@default'"
  fi
}

ask_user
prereq
install

echo -e $END_NOTICE