#!/usr/bin/bash
# SJP 30 Dec 2015
#
# Copy and process photos from a cam-equipped raspi

########### Constants ##################
campi="neatherd"                # hard-code source hostname for the moment
sourcedir="/home/st33v/pix"    # where the image is on the source computer (i.e. $campi)
thisdir="/home/st33v/cams"     # this directory (on this computer)
threshold="2000"                # minimum value of average pixel brightness. Tests if pic is too dark
########### end Consts ################

cd ${thisdir}
########### Functions ##################
# get the filename of the most recent photo stored on this computer.
newestpicfunc () { newestpic=$(ls ${campi}/*.jpg -t | head -1); }
########### end Funcs #################

# record the latest photo BEFORE we look for a new one
newestpicfunc; oldpic=${newestpic}
# echo "Before: oldpic is ${oldpic}"

# Copy any photos from the camera-equipped source ($campi)
# This script is on a rapid timer so there should only ever be one photo (if any).
scp ${campi}:${sourcedir}/*.jpg ${campi}/. 2>/dev/null
# Delete the photo from the source computer.
ssh $campi "rm ${sourcedir}/*.jpg" 2>/dev/null
# cp ${oldpic} ${thisdir}${campi}/zzz.jpg   # testing 

# get the filename of the NEW photo, it there is one
newestpicfunc; newpic=${newestpic}
#echo "After: newpic is ${newpic}"

if [[ "$oldpic" == "$newpic" ]] ; then 
    # echo no new photos so exit now
    exit 0
fi

# NeatHerd doesn't have enough RAM to perform image processing, so let's try it on STAN

# Check to see if the pic is too dark (i.e. taken at night)
mean=$(identify -format %[mean] ${newpic} | sed s/[.].*//)
# echo "mean is |$mean|"
# too dark (nighttime)
if [[ "${mean}" -lt "${threshold}" ]] ; then
    rm $newpic
#    echo mean of $mean is too low. It is nighttime.
    exit 13
fi

# Improve sharpness and resize photo, ready for upload to webserver
# Break into two steps to avoid out-of-memory errors (OS kills process)
convert ${newpic} -unsharp 1.5x1+0.7+0.02 temp.jpg
convert temp.jpg -resize 33% -quality 70 ${newpic}
rm temp.jpg
   
. ~/cams/sendpix.sh

#exit(0)     # force success exit code for fussy systemd