#!/usr/bin/env bash

# CONSTANTS
DEBUG=true
TMP_ERROR=$(mktemp -t "$(basename $0).XXXXXXXX" --tmpdir=/run/user/$(id -u))
SCRIPT=$1

# FUNCTIONS

function return {
  builtin return ${1:-}
}

function exit {
  code=${1:-0}

  stack_lines=("${BASH_LINENO[@]}")
  stack_functions=("${FUNCNAME[@]}")
  stack_sources=("${BASH_SOURCE[@]}")
  unset stack_lines[-1]
  unset stack_lines[-1]
  unset stack_functions[0]
  unset stack_functions[-1]
  stack_functions[-1]='<main>'
  unset stack_sources[0]
  unset stack_sources[-1]
  stack_lines=("${stack_lines[@]}")
  stack_functions=("${stack_functions[@]}")
  stack_sources=("${stack_sources[@]}")

  if [[ -s $TMP_ERROR ]]; then
    last_error=$(tail -n1 $TMP_ERROR)
    $DEBUG && >/dev/tty echo '---stderr---'
    >&4 echo "ERROR $code: [$last_error]"
  fi

  for i in "${!stack_functions[@]}"; do
    >&4 printf "\t%30s\t%s\n" "${stack_sources[$i]}:${stack_lines[$i]}" "${stack_functions[$i]}"
  done

  # echo "${stack_lines[@]}"
  # echo "${stack_functions[@]}"
  # echo "${stack_sources[@]}"

  cleanup ${code}
}

function success {
  if [[ -s $TMP_ERROR ]]; then
    $DEBUG && >/dev/tty echo '---stderr---'
    >&2 cat $TMP_ERROR
  fi
  cleanup 0
}

function cleanup {
  code=${1:-0}
  $DEBUG && >/dev/tty echo "---exit $1---"
  trap - ERR TERM INT EXIT
  rm $TMP_ERROR
  exec 3>&- 4>&-
  builtin exit $code
}

# MAIN

set -TEue -o pipefail
trap 'exit $?' ERR TERM INT EXIT

# magic FD
exec 3>$TMP_ERROR 4>/dev/stderr
$DEBUG && >/dev/tty echo '---stdout---'
source $SCRIPT 2>&3
success