#!/bin/sh
set -e
# tests all functions 3 times using numbers generated using $RPATH
# psh-prng is used here with my testing
# math is comparred to bc
fd() {
  m="$1"; n=1; while [ "$m" ]; do
    next="${m%?}"
    [ "$n" -eq "${#1}" ] && {
      echo "${m%next}"
      break
    }
    : $((n+=1)); m="$next"
  done
}
for i in addition/add subtraction/sub multiplication/mul division/div; do
  for n in 1 2; do
    ran="$(fd $(${RPATH}))"; : $((ran-=1)); until [ "$ran" -eq 1 -o "$ran" -eq 0 ]; do
      ran="$(fd $(${RPATH}))"; : $((ran-=1))
    done
    case $ran in
      0) ran=""; tn="$(${RPATH}).$(${RPATH}) $(${RPATH})";;
      1) ran=""; tn="$(${RPATH}) $(${RPATH}).$(${RPATH})"
         ran="$(fd $(${RPATH}))"; : $((ran-=1)); until [ "$ran" -eq 1 -o "$ran" -eq 0 ]; do
           ran="$(fd $(${RPATH}))"; : $((ran-=1))
         done
         case $ran in
           1) ran=""; tn="${tn% *}.$(${RPATH}) ${tn#* }"
         esac
    esac
    # use random number to determine if number will have decimal place
    case $i in
      addition/add) op="+";;
      subtraction/sub) op="-";;
      multiplication/mul) op="*";;
      division/div) op="/"
    esac
    aws="$(echo ${tn% *}${op}${tn#* } | bc -l)"; case "$(fd $aws)" in
      '.') aws="0${aws}"
    esac
    printf '  %s\n%s %s\n_____\nbc:  %s\n' "${tn% *}" "$op" "${tn#* }" "$aws"
    printf 'psh: %s\n\n' "$(${i} ${tn% *} ${tn#* })"
  done
done