#!/bin/bash
#
# netdrawcopy -- 2007-12-10, last edit 2008-09-30
#
# make a midnight copy of netdraw.png, called from crontab at a minute 
#  after midnight, keep a list of most recent images, update the netdraw 
#  web page, update the monthly summary image and copy the monthly image 
#  on the first of each month
#
# last sample time was 23:59, so we processing yesterday's stuff
#
# Copyright (C) 2007,2008 Grant Coady <http://bugsplatter.id.au/> GPLv2
#
# 2008-09-30
# change .conf reader to use case, cleaner.  still need to rearrange data 
#  fixup to be done before chart draw
#
# 2008-09-06
# update the web page after processing completed, trial a bash based .conf 
#  reader first, those multiple awk calls look bad ;)
#
# 2008-05-17
# repair and trim the data sample file, perhaps redraw yesterday's chart
#
DOT_CONF="/etc/netdraw.conf"

while read key value rest
do
	case $key in
		codepath)	CODEPATH=$value;;
		htmlpath)	IMAGEPATH=$value;;
		imagfile)	IMAGEFILE=$value;;
		daycopylog)	COPYLOG=$value;;
		daylogmax)	COPYMAX=$value;;
		copytmp)	COPYTMP=$value;;
		moncopylog)	MONCOPYLOG=$value;;
		monlogmax)	MONCOPYMAX=$value;;
		datapath)	DATAPATH=$value;;
		datafile)	DATAFILE="$DATAPATH/$value";;
		sampletime)	SAMPLTIM=$value;;
		samplemax)	SAMPLMAX=$value;;
		*)		continue;;
	esac
done < $DOT_CONF

DATESTAMP=$(date -d yesterday +%F)
IMAGENEW="netdraw-$DATESTAMP.png"

cd $IMAGEPATH || exit 1

cp -f $IMAGEFILE $IMAGENEW		# daily snapshot file
echo $IMAGENEW >> $COPYLOG		# add to log

# limit length of daily snapshots log
sort -r $COPYLOG | uniq | head -$COPYMAX > $COPYTMP && \
		mv -f $COPYTMP $COPYLOG

# remove old daily snapshots
ls netdraw-*png > $COPYTMP
cat $COPYTMP $COPYLOG | sort | uniq -u | xargs rm -f

# perhaps do monthly processing
MONTHDAY=$(date +%d)		# 2008-03-01 really fix last month summary
if [ $MONTHDAY -eq 1 ]; then # month start? create last month's summary image
	IMAGENEW="netdrawmon-$DATESTAMP.png"
	$CODEPATH/netdrawmon -v show_date="$DATESTAMP"
	echo $IMAGENEW >> $MONCOPYLOG

	# limit length of monthly snapshots log
	sort -r $MONCOPYLOG | uniq | head -$COPYMAX > $COPYTMP && \
			mv -f $COPYTMP $MONCOPYLOG

	# remove old monthly snapshots
	ls netdrawmon-*png > $COPYTMP
	cat $COPYTMP $MONCOPYLOG | sort | uniq -u | xargs rm -f
fi

# update the web page
$CODEPATH/netdrawhtml

# fill in any missing samples with zero data and trim sample file, notice 
#  the illegal sample time filter, change this to suit if you are sampling 
#  other than at hh:?4 or hh:?9 minutes in the cron job

cp -f $DATAFILE $DATAFILE.bkp

# data record format: 2008-05-17.05:14 1193463140 109699700

# this is broken, cannot handle switch from daylight savings to normal time
#awk -v sampletime=$SAMPLTIM -v flagfile="$DATAFILE.flag" '
#{
#        split($1, a, "[-.:]")
#
#	m = a[5] % 10; if (!(m == 4 || m == 9)) { next } # drop bad samples
#
#	datetime = mktime(a[1]" "a[2]" "a[3]" "a[4]" "a[5]" 30")
#	if (last_datetime && datetime - last_datetime > sampletime) {
#		last_datetime += sampletime
#		while(last_datetime < datetime) {
#			print strftime("%F.%H:%M", last_datetime) " 0 0"
#			last_datetime += sampletime
#			print strftime("%F", last_datetime) > flagfile
#		}
#	}
#	print
#	last_datetime = datetime
#}
#' $DATAFILE > $COPYTMP && tail -$SAMPLMAX $COPYTMP > $DATAFILE && rm $COPYTMP

# trim sample file, data recovery is manual until the above is fixed to use 
#  epoch time
mv $DATAFILE $COPYTMP && tail -$SAMPLMAX $COPYTMP > $DATAFILE && rm $COPYTMP

# perhaps redraw daily summary chart/s, we do this here as we now have all 
#  the expected hour marker records in the sample data file
#if [ -r "$DATAFILE.flag" ]; then
#	uniq $DATAFILE.flag > $COPYTMP
#	while read end_date crap; do
#		$CODEPATH/netdraw end_date="$end_date"
#	done < $COPYTMP
#	rm $DATAFILE.flag $COPYTMP
#fi
# end