#! /bin/bash

#set -x

FILE_IN="${1}"

safe_count=0

while read -r l; do
  echo "reading new line [$l]"

  IFS=" "
  read -ra line_split <<< "${l}"
  unset IFS

  # start with the first val
  prev_val="${line_split[0]}"

  is_safe=1

  # if positive, going up, if negative, going down!
  is_up_down="$((line_split[1] - line_split[0]))"

  if [[ "${is_up_down}" -ge 0 ]]; then
    echo "Initially going up"
  else
    echo "Initially going down"
  fi

  for v in "${line_split[@]:1}"; do
    echo "checking [${v}] against previous [${prev_val}]"
    prev_diff=$((v - prev_val))
    echo "diff ${prev_diff}"


    if [[ "${prev_diff}" -gt 0 ]]; then
      echo "going up"
      if [[ "${is_up_down}" -le 0 ]]; then
        echo "wrong direction"
        is_safe=0
      fi
    else
      echo "going down"
      if [[ "${is_up_down}" -ge 0 ]]; then
        echo "wrong direction"
        is_safe=0
      fi
    fi

    if [[ "${prev_diff#-}" -le 0 ]] || [[ "${prev_diff#-}" -ge 4 ]]; then
      echo "outside range"
      is_safe=0
    fi

    if [[ "${is_safe}" -ne 0 ]]; then
      echo "safe"
    else
      echo "unsafe"
    fi
    prev_val=$v
  done

  safe_count=$((safe_count + is_safe))
done <"$FILE_IN"

echo "final safe count ${safe_count}"