ERR=false

do_install()
{
  mkdir tracker_working
  cd tracker_working
  wget --no-check-certificate https://content.ilabsolutions.com/wp-content/uploads/2013/01/ilab_tracker_linux.tar.gz
  tar xvzf ilab_tracker_linux.tar.gz
  wget --no-check-certificate https://content.ilabsolutions.com/wp-content/uploads/2012/06/tracker_linux.tar.gz
  tar xvzf tracker_linux.tar.gz
  mv start-tracker /usr/bin
  mv usagetracker.desktop /etc/xdg/autostart
  cp ../tracker.conf ./UsageTracker
  mkdir /opt/iLab
  chmod augo+rwx /opt/iLab
  mv UsageTracker/ /opt/iLab/
  dos2unix /opt/iLab/UsageTracker/UsageTracker.sh
  touch /opt/iLab/UsageTracker/usage_tracker.log
  touch /opt/iLab/UsageTracker/error_trace.log
  find /opt/iLab -type d -exec chmod augo+rwx {} +
  find /opt/iLab -type f -exec chmod augo+rw {} +  
  chmod a+x /opt/iLab/UsageTracker/UsageTracker.sh
  cd ..
  rm -rf tracker_working
}

check_error()
{  
  if [ "$ERR" = true ]; then
    error_and_exit
  fi
}

error_and_exit()
{
  echo "==============================================================="
  echo "ABORTING! "
  echo "An error was encountered while trying to install the usage tracker."
  echo "Please correct the errors above before proceeding"
  echo "Please contact support@ilabsolutions.com for help if needed."
  echo "==============================================================="
  exit 1
}

installation_completed()
{
  echo "==============================================================="
  echo "SUCCESS! "
  echo "Installation of the iLab usage tracker was successful."
  echo "You must restart the computer for the changes to take effect."  
  read -p "Do you want to restart now? (y/n)?" choice
  echo
  case "$choice" in 
    y|Y ) shutdown -r now;;
    n|N ) echo "continuing without restart";;
    * ) echo "invalid input. continuing without restart";;
  esac  
  echo "==============================================================="  
}


preamble()
{
  echo "==============================================================="
  echo "Welcome to the iLab usage tracker installation! "
  echo "You will now attempt to install the usage tracker client on the current computer."
  read -p "Do you want to continue? (y/n)?" cont
  echo
  case "$cont" in 
    y|Y ) echo "proceeding with installation";;
    n|N ) echo "Aborting..."; exit 1;;
    * ) echo "invalid input. Aborting..."; exit 1;;
  esac
  echo "==============================================================="  
}

check_java_version()
{
  JAVA_VER=$(java -version 2>&1 | sed 's/java version "\(.*\)\.\(.*\)\..*"/\1\2/; 1q')
  if [ "$JAVA_VER" -ge 16 ]; then
    echo "OK: java is 1.6 or newer" 
  else
    echo "ERROR: java version is too old. Please install java version 6 or better"
    ERR=true    
  fi  
}

check_if_root()
{
  if [ "$(whoami)" != "root" ]; then
    echo "ERROR: Sorry, you are not root. Try sudo."
    ERR=true
  fi  
}

check_if_tracker_file_exists()
{
  if [ ! -f ./tracker.conf ]; then
  echo "ERROR: Configuration file not found! "
  echo "Please download a config file from iLab and rerun the command from the folder which contains the file."  
  ERR=true
}

check_required_commands()
{
  command -v wget >/dev/null 2>&1 || { echo >&2 "ERROR: wget command not found. Installer needs 'wget' to be installed."; ERR=true; }
  command -v dos2unix >/dev/null 2>&1 || { echo >&2 "ERROR: dos2unix command not found. Installer needs 'dos2unix' to be installed."; ERR=true; }
}

preamble
check_java_version
check_if_root
check_if_tracker_file_exists
check_required_commands
check_error
do_install
check_error
installation_completed