#!/usr/bin/perl -w

$|=1 if $ENV{DEBUG};
use strict;
use diagnostics;
use DBI;
use Text::CSV;
use Date::Manip;

use LWP::UserAgent;
my $ua = LWP::UserAgent->new;
$ua->agent("Munin[river_levels_]");

my @stations = qw(
1129 1135 1133 1143 1132 1137 1134 1145 1139 1131 1130 1144 9274
);

my $base = "https://check-for-flooding.service.gov.uk/station-csv/";

my $db = DBI->connect("dbi:SQLite:dbname=rivers.db") or die $DBI::errstr;

my $recordlevel    = $db->prepare("REPLACE INTO levels (stationid, timestamp, level) VALUES (?,?,?)") or die $db->errstr;
my $getlastrecord  = $db->prepare("SELECT MAX(timestamp) FROM levels WHERE stationid=?")              or die $db->errstr;

sub getlatest($) {
        my ($id) = @_;
        $getlastrecord->execute($id);
        my ($lastrecord) = $getlastrecord->fetchrow();
	return $lastrecord ? $lastrecord : "0";
}


foreach my $station (@stations) {
        print STDERR "[$station] Requesting $base$station\n" if $ENV{R_DEBUG};
        my $req = HTTP::Request->new(GET => $base . $station);
        my $res = $ua->request($req);
	my $content = $res->content;
	my $last = getlatest($station);
	print "[$station] Last record was $last\n" if $ENV{R_DEBUG};
	foreach my $line (sort split(/^/m, $content)) {
		next if $line =~ /Timestamp/;
		chomp($line);
		my ($ts, $level) = split(/,/, $line);
		if($ts le $last) {
			print "[$station] Skipping $level at $ts\n" if $ENV{R_DEBUG};
		} else {
			print "[$station] Recording $level at $ts\n" if $ENV{R_DEBUG};
			$recordlevel->execute($station, $ts, $level);
		}
	}
}