#!perl -w

use strict;
use DBI;
use LWP::Simple;

my $img_url = "http://weather.unisys.com/satellite/sat_ir_west.gif";

my $dbh = DBI->connect(
    'dbi:mysql:weather_images', 'user', 'secret', {
        RaiseError => 1, AutoCommit => 1
    }
);

my ($min, $hour, $day, $mon, $year) = (localtime())[1..5];
$year += 1900;

my $img_name = "$mon-$day-$year-$hour:$min";
my $img_data = get($img_url);

die("failed to fetch image from internet!\n")
    unless ( defined($img_data) );

# fetch the last row we added to the table
my $latest_entry = $dbh->selectrow_arrayref(
    'SELECT image_file FROM gw_ir ORDER BY image_id DESC LIMIT 1'
);

# either no data in database or the file contents
# have changed since the last update
if (not defined($latest_entry) or $latest_entry->[0] ne $img_data) {
    $dbh->do(
        'INSERT INTO gw_ir (image_name, image_file) VALUES(?,?)',
        undef, $img_name, $img_data
    );

    warn("File was not current; updates made.\n");
}

else {
    warn("File was current, no updates made.\n");
}

$dbh->disconnect();