#!/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
wanWebServer="f3rr3t.com"
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 ################

# cam names in an array:
declare -a camz=(neatherd lucerne)

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

cd ${thisdir}

for campi in "${camz[@]}"
do
    # record the latest photo BEFORE we look for a new one
    newestpicfunc; oldpic=${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
        continue
    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.
        continue
    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

    # upload latest pic to web server
    echo "/home/st33v/cams/$newpic"
    echo "$wanWebServer:/home/st33v/farm/cam/$campi/"
    scp /home/st33v/cams/$newpic $wanWebServer:/home/st33v/farm/cam/$campi/.
done

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