#!/usr/bin/perl

#this script will pregenerate graphs for all the platforms in the given db instance for the given latest time_interval

use strict;
use DBI;
use XML::LibXML;
use LWP::UserAgent;

#load database and path info
my ($env,$time_interval,$unit_conversion) = @ARGV;

my $time_interval_label = $time_interval;
$time_interval_label =~ s/ /_/g;

my $xp_env = XML::LibXML->new->parse_file("../environment_xenia_$env.xml");
my $xp_graph = XML::LibXML->new->parse_file("environment_xenia_graph.xml");

my $db_host   = $xp_env->findvalue('//db/host');
my $db_name   = $xp_env->findvalue('//db/name');
my $db_user   = $xp_env->findvalue('//db/user');
my $db_passwd = $xp_env->findvalue('//db/passwd');

my $dir_tmp = $xp_env->findvalue('//path/dir_tmp');
my $dir_base = $xp_env->findvalue('//path/dir_base');
my $http_base = $xp_env->findvalue('//path/http_base');
my $http_xenia_graph = $xp_env->findvalue('//path/http_xenia_graph');


#establish database connection
my ($dbh,$sth,$sql,$sth_2,$sth_3);
if ($db_host eq '') { $dbh = DBI->connect ("dbi:Pg:dbname=$db_name", "$db_user", "$db_passwd"); } #remove host reference if local
else { $dbh = DBI->connect ("dbi:Pg:dbname=$db_name;host=$db_host", "$db_user", "$db_passwd"); }
if ( !defined $dbh ) {die "Cannot connect to database!\n";}

#get platforms for this xenia instance
$sql = qq{ select row_id,platform_handle from platform };
#print "sql:".$sql."\n";
$sth = $dbh->prepare( $sql );
$sth->execute();
if ($sth->rows == 0) { print "no data\n"; &exit_no_data; }

#####################################################################
while ( my ($platform_id,$platform_handle) = $sth->fetchrow() ) {
	print "platform_id:$platform_id\n";

#get sensor_id's for platforms
$sql = qq{ select row_id,m_type_id from sensor where platform_id = $platform_id };
#print "sql:".$sql."\n";
$sth_2 = $dbh->prepare( $sql );
$sth_2->execute();

#####################################################################
while ( my ($sensor_id,$m_type_id) = $sth_2->fetchrow() ) {
        #print "  sensor_id:$sensor_id\n";

#get obs_type and uom for associate sensor_id.m_type_id
$sql = qq{ select t1.standard_name,t2.standard_name from obs_type t1,uom_type t2 where t1.row_id = (select obs_type_id from m_type where row_id = $m_type_id) and t2.row_id = (select uom_type_id from m_type where row_id = $m_type_id) };
#print "sql:".$sql."\n";
$sth_3 = $dbh->prepare( $sql );
$sth_3->execute();
my ($obs_type,$uom_type) = $sth_3->fetchrow(); 

if ($unit_conversion eq 'en') { #en is for the default english unit conversion
	$uom_type = $xp_graph->findvalue('//observation_list/observation[@m_type_id="'.$m_type_id.'"]/standard_uom_en');
}
print "  $obs_type:$uom_type\n";

my $url = $http_xenia_graph."environment=$env&sensor_id=$sensor_id&output=graph&time_interval=$time_interval&unit_conversion=$unit_conversion";
print "$url\n";
my $url_table = $http_xenia_graph."environment=$env&sensor_id=$sensor_id&output=table&time_interval=$time_interval&unit_conversion=$unit_conversion";

my $file_to = $dir_base."platform/$platform_handle/graph/$obs_type:$uom_type:$time_interval_label.png";
print "$file_to\n";
my $file_to_table = $dir_base."platform/$platform_handle/graph/$obs_type:$uom_type:$time_interval_label.html";

my $url_test = $http_base."platform/$platform_handle/graph/$obs_type:$uom_type:$time_interval_label.png";
print "$url_test\n";

my $ua = new LWP::UserAgent;
$ua->timeout(300); #number of seconds before timeout, default is 3 minutes(180 seconds)

#determine age of existing files
my $head = $ua->head($url_test);
#the below returns the file last modified like: Sat, 18 Nov 2006 14:17:21 GMT
my $time_file = $head->{_headers}{'last-modified'}; ## not 'date'
my ($weekday,$day,$month,$year,$hour_minute_second) = split(/\s+/,$time_file);
my $time_file_sec = `date --date='$day $month $year $hour_minute_second +0000' +%s`;
#print "time_file:$time_file_sec";
chomp($time_file_sec);

my $time_now_sec = `date -u +%s`;
#print "time_now:$time_now_sec";
chomp($time_now_sec);

my $time_diff = $time_now_sec - $time_file_sec;
#print "time_diff:$time_diff\n";
if ($time_diff > 3600) { #existing files are older than an hour so go ahead and generate new

	my $response = $ua->mirror($url,$file_to) ; if ($response->is_error) { print "couldn't retrieve file\n"; exit 0; }
	print "ok graph\n";

	my $response = $ua->mirror($url_table,$file_to_table) ; if ($response->is_error) { print "couldn't retrieve file\n"; exit 0; }
	print "ok table\n";

}

} #while $sensor_id

} #while $platform_id

exit 0;

#####################################################################
sub exit_no_data {
        $sth->finish;
        $dbh->disconnect();
        exit 0;
}