#! /bin/bash

# DESCRIPTION:
#   returning current username if privileged rights are exist
#   or
#   returning error, if privileged rights are not exist
#
# DEPENDENCIES:
#   - whoami
#
# PARAMETERS:
#   1: "qn" - execution without pauses
#   2: custom configuration file path
#
# FUNCTIONS:
#

#######################################
# Print message and add to log.
# Globals:
#   logs
# Arguments:
#   1: message to print and logging
#######################################
addtologs() {
  echo "$(date +'%Y.%m.%d-%H:%M:%S') $1" | tee -a "${logs}"
}

#######################################
# Waiting for press [ENTER].
# Globals:
#   None
# Arguments:
#   None
#######################################
execpause() {
  read -r -p "Press [ENTER] to continue... "
}

#######################################
# Exit procedure.
# Globals:
#   show
# Arguments:
#   None
#######################################
execquite() {
  addtologs "execution time is $(($(date +%s)-time)) seconds, exit"
  if [ "${show}" != "qn" ]; then
    execpause
  fi
  exit
}

#######################################
# Error exit procedure
# Globals:
#   None
# Arguments:
#   1: message to print and logging
#######################################
execerror() {
  addtologs "error: $1"
  execquite
}

#######################################
# Parsing config file and creating global vars.
# Globals:
#   None
# Arguments:
#   None
#######################################
getconfig() {
  logs=$(grep "logs=" "${conf}" | cut -d= -f2)
}

#######################################
# Checking user rights.
# Globals:
#   None
# Arguments:
#   None
# return:
#   0 - if privileged rights, 1 - if not privileged rights
#######################################
checkroot() {
  if [ "${EUID}" -ne 0 ]; then
    return 1 # false
  else
    return 0 # true
  fi
}

#
# VARIABLES:
#

show=$1
conf=$2
if [ -z "${conf}" ] || [ "${conf}" == "-" ]; then
  conf="$(dirname "$(realpath "$0")")/$(basename -s .sh "$0").conf"
fi

time=$(date +%s)
cd "$(dirname "$(realpath "$0")")" || execerror
if [ ! -e "${conf}" ]; then
  :
else
  getconfig
fi
if [ -z "${logs}" ]; then
  logs=/dev/null
elif [ ! -e "${logs}" ]; then
  touch "${logs}"
fi

#
# MAIN:
#

checkroot \
&& echo "Running as $(whoami)" \
&& execquite \
|| execerror "Restart this as root!"