#!/bin/bash
# go-photo.sh script (run in background, then launch go-fbi.sh)  
# It copies the next photo into the free buffer and then updates the display alias
# source photos are held in the /photos/ folder (fetching and resizing is performed by the fetch-resize script)
# both buffers1&2.jpg and display.jpg are held in the /ram-disk/ folder (actual display is performed by the fbi script)
showtime=4 #photo show time -1 (so 4 = 5 seconds total)
cfile="0" # current file name
ctop="0" # current top by date
nbuf="buffer1.jpg" # next (free) buffer
# loop forever
while [ true ]; do
	top="0" # no top found
	next="0" # no next found
	# Scan the photos dir for the current file
	for filename in $(ls -A1c /photos/*.jpg); do
	# note, when you ls a different folder, the path is added to each file name (so file is /photos/name.jpg )
	if [ $top = "0" ]; then
		top=$filename
		if [ $filename != $ctop ]; then next=$filename; fi
	fi
	# find the next file AFTER the current
	if [ $next = "0" ]; then
		if [ $cfile = "0" ]; then next=$filename; fi
		if [ $filename = $cfile ]; then cfile="0"; fi
	fi
	done
	# if no next found, use top
	if [ $next = "0" ]; then next=$top; fi
	ctop=$top
	# OK, we have the next file, pause in case fbi is still reading the free buffer
	sleep 1
	cp -f $next /photos/ram-disk/$nbuf
	cfile=$next
	if [ $nbuf = "buffer1" ] then;
		nbuf="buffer2.jpg"
	else
		nbuf="buffer1.jpg"
	fi
	# now switch the link on first pass should creates display.jpg)
	ln -s -f /photos/ram-disk/$nbuf /photos/ram-disk/display.jpg
	# wait for the rest of the show time
	sleep $showtime
	# now go find the next
done