<?
# Jeff Brown
# November 1th, 2010
# Version: 2.3
# http://photonicsguy.ca/nslu2

header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1
header("Expires: Sat, 26 Jul 1997 05:00:00 GMT"); // Date in the past

date_default_timezone_set("America/Toronto");

include('config.inc.php');
$INTERVAL=2;
$TZoffset=-3600*4;
$link = mysql_connect($MYSQL_HOST,$MYSQL_USER,$MYSQL_PASS);
if (!$link) {
	echo "Unable to connect to DB: " . mysql_error();
	exit;
}

if (!mysql_select_db($MYSQL_DB)) {
    echo "Unable to select mydbname: " . mysql_error();
    exit;
}
plot_picdata();

header('Content-Type: image/jpeg');
$file=$datadir."pic.gnuplot";
	$fp=fopen($file,'w');
	$tfrom=time()+$TZoffset-($INTERVAL*24*3600);
	$tto=(time()+$TZoffset);
#Blackberry size: 480,360

	$plot='set terminal jpeg nocrop size 1000,800
set xdata time
set timefmt "%s"
#set format x "%d/%m\n%I:%M"
set format x "%a %d\n%I:%M %p"
set grid nopolar
set grid xtics mxtics ytics mytics noztics nomztics \
 nox2tics nomx2tics noy2tics nomy2tics nocbtics nomcbtics
#set grid layerdefault   linetype 0 linewidth 1.000,  linetype 0 linewidth 1.000
set key inside right bottom vertical Right noreverse enhanced autotitles box
set title "'.date("F j, Y, g:i a").'"
#set style data fsteps
#set xlabel "Date\nTime"
#TZoffset='.$TZoffset.'
#set xrange ["'.$tfrom.'":"'.$tto.'"] noreverse nowriteback
set ylabel "Temperature"
#set yrange ['.$YRANGE.']
set yrange [0:30]
#set xtics 1*3600
#set mxtics 4
#set mytics 1
plot \'data/_sql_pic.dat\' using 1:2 t \'PIC\' with lines lw 2';
$t=',\
\'data/_sql_3.dat\' using 1:2 t \'Sensor 1\' with lines lw 1,\
\'data/_sql_3.dat\' using 1:2 t \'Sensor 2\' with lines lw 1,\
\'data/_sql_3.dat\' using 1:2 t \'Sensor 3\' with lines lw 1
';
fwrite($fp,$plot);
fclose($fp);
	passthru($gnuplot.' '.$datadir.'pic.gnuplot');


function plot_picdata() {
	global $datadir;
	global $INTERVAL;
	global $TZoffset;
	$file=$datadir."_sql_pic.dat";
	$fp=fopen($file,'w');
	$sql="SELECT UNIX_TIMESTAMP(`dt`),`temp_c` FROM `pic` WHERE 1 AND `dt`> DATE_SUB(NOW(),INTERVAL $INTERVAL DAY) ORDER BY `dt` ASC";
#	$sql="SELECT UNIX_TIMESTAMP(`dt`),avg(`temp_c`) FROM `pic` WHERE 1 AND `dt`> DATE_SUB(NOW(),INTERVAL 2 DAY) group by DATE_FORMAT(`dt`,'%j.%k') ORDER BY `dt` ASC";
	$result=mysql_query($sql);
	fwrite($fp,"# PIC Controller\n# ".date("F j, Y, g:i a")."\n#unixtime\ttemperature\n");
	while ($row = mysql_fetch_assoc($result)) {
		if(isset($row['temp_c'])) {
			fwrite($fp,$row['UNIX_TIMESTAMP(`dt`)']+$TZoffset."\t".$row['temp_c']."\n");
		} else {
			fwrite($fp,"\n"); 
		}
	}
	fclose($fp);
}