#!/usr/bin/perl
#
use strict;
use RRDs;
use InfluxDB;
use Data::Dumper;
my @rrd_array;
my $DB = "/var/www/rrd/PVGIS_forecast.rrd";
my $start = "midnight+6h"; # Mitternacht+6h
my $end = "noon+9h";       # Mittag+9h
my ($start, $step, $columns,$data) = RRDs::fetch($DB, "--start=$start", "--end=$end", "AVERAGE")
   or die "Cannot fetch rrd ($RRDs::error)";
my $ii = 0;
     OUTER:foreach my $line (@$data) {
           $start += $step;
           INNER:foreach my $val (@$line) {
                $val = "N/A" unless defined $val;
		        if($val eq "N/A"){last OUTER;}
				$rrd_array[$ii][0] = ($start);
				$rrd_array[$ii][1] = ($val);
				++$ii;
          }
     }
my @matrix=(@rrd_array);
#print Dumper(@matrix);
#
    my $ix = InfluxDB->new(
        host     => '127.0.0.1',
        port     => 8086,
        username => 'root',
        password => 'root',
        database => 'pv_wetter',
    );
$ix->write_points(
    data => {
            name    => "test",
            columns => [qw(time forecast)],
            points  => \@matrix,
		    },
) or die "write_points: " . $ix->errstr;
    my $rs = $ix->query(
        q => 'select * from test ',
        time_precision => 's',
    ) or die "query: " . $ix->errstr;