## CONSTANTS

CURRENT_SOURCE="${BASH_SOURCE[0]}"

# TODO: read and understand the catch function
# https://stackoverflow.com/a/59592881/5018486

## FUNCTIONS

function exit {
  local error_code stack_lines stack_functions stack_sources
  error_code=${1:-0}

  stack_lines=("${BASH_LINENO[@]}")
  stack_functions=("${FUNCNAME[@]}")
  stack_sources=("${BASH_SOURCE[@]}")

  unset stack_functions[0]
  unset stack_sources[0]
  unset stack_lines[-1]
  #
  # # remove 1 on head list
  # [[ ${#stack_lines[@]} > 0 && ${stack_lines[0]} == 1 ]] && unset stack_lines[0]
  #
  # # remove 0 on tail list
  # [[ ${#stack_lines[@]} > 0 && ${stack_lines[-1]} == 0 ]] && unset stack_lines[-1]

  rm $script
  if [[ $error_code > 0 ]]; then
    printf "\nEXIT #${error_code} due to error at line ${stack_lines} : \n-----------------------------------------\n"
    [[ -s /tmp/error ]] && echo -ne 'CAUSE:\t\t' && cat /tmp/error
    echo -e "FUNCNAME:\t${stack_functions[@]}" >&2 # inner outer main
    echo -e "BASH_SOURCE:\t${stack_sources[@]}" >&2
    echo -e "BASH_LINENO:\t${stack_lines[@]}" >&2
    trap - ERR TERM INT EXIT
    builtin exit "${error_code}"
  else
    echo __REAL_SUCCESS
  fi
}

function raise_error {
  message=${1:-an undefined error has occured!}
  code=${2:-1}
  echo "error ${code}: ${message}" >&2
  trap - ERR TERM INT EXIT
  exit $code
}

# MAIN
_BACKTRACE=${_BACKTRACE:-false}
# echo "_BACKTRACE=${_BACKTRACE}"

# a bit of magic: prevent performing the original script and rather running the backtrace version
${_BACKTRACE} && builtin exit

set -TEue
trap 'exit $?' ERR TERM INT EXIT
# echo "current: ${BASH_SOURCE[-1]}"
# echo "ARGV   : $@"
export _BACKTRACE=true

source=${BASH_SOURCE[-1]}
script="${source}.backtrace"
cp $source $script

# prepend the set Strict command
sed -i '1s/.*/set -TEue/' $script

# a bit of magic: save stderr into /tmp/error while outputing stdout!
{
  $script 3>&1 1>&2 2>&3 | tee /tmp/error
} 2>/dev/null >/dev/null

# SOME VARIANTS (which does not work actually)
# ----------
# exec ${BASH_SOURCE[-1]} $* 2>/tmp/error
# eval $(<${BASH_SOURCE[-1]}) $* 2>/tmp/error
# eval $(<$script) $* 2>&1 >/tmp/error
# $script $* 2>&1 >>/tmp/error
# ERROR=$($script 3>&1 1>&2 2>&3 | tee /tmp/error)