#!/bin/bash

# Get screenshots from bow, discard them if they dont change much.

source /usr/local/lib/err
[[ $EUID == 0 ]] || exec sudo -E "${BASH_SOURCE[0]}" "$@"

f=/run/user/1000/ziva-tmp.jpg

cd /d/ziva-log
shopt -s nullglob
jpgs=( 20*jpg )
if (( ${#jpgs[@]} >= 1 )); then
  lastf=$(ls -1 20*jpg  | tail -n1)
fi

ssh bow DISPLAY=:0 scrot -z $f 2>/dev/null || exit 0
rsync --inplace bow:$f /d/ziva-log 2>/dev/null || exit 0
ssh bow rm -f $f

same=false
if [[ $lastf ]]; then
  # returns 2 on error, but maybe in that case we want to ignore, file the image away
  # and then it can go away in a subsequent comparison. going with that for now.
  diff=$(compare -metric MSE $lastf ziva-tmp.jpg /dev/null |& sed 's/[^0-9].*//') ||:
  if printf "%s\n" "$diff" | egrep '^[0-9]+$' &>/dev/null && (( diff < 200 )); then
    same=true
  fi
fi

if $same; then
  rm -f ziva-tmp.jpg
else
  mv ziva-tmp.jpg $(date +%F.%R).jpg
fi