#!/usr/bin/perl -w

use XML::FeedPP;
use XML::LibXML;
use XML::Rules;
use LWP::Simple;
use strict;
use warnings;

# get the Atom feed from the USGS

my $source = 'http://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/4.5_day.atom';
my $feed = XML::FeedPP->new( $source );

# Incorporating a rules section so that we can extract the information from the CDATA section
# and any other specific fields we might need.  First attempt will be to pull the 'Updated'
# field data from the Atom feed.  I tried to follow the example in the CPAN summary but I'm
# clearly lost.  

my @rules = (
         _default => sub {$_[0] => $_[1]->{_content}},
         id => sub {$_[0] => $_[1]->{_content}},
#        author => undef, # ignoring the author because I already know it's the USGS
         author => sub {$_[0] => $_[1]->{_content}},
         updated => sub {print "$_[1]->{updated}\n";
         },
);

my $parser = XML::Rules->new(rules => \@rules);
my $atom = $feed->to_string();
$parser->parse( $atom );

# This section extracts the title field, then performs string manipulations to extract the
# long location data and the magnitude.  Funny that USGS does not have a magnitude field
# in this feed.

foreach my $quake( $feed->get_item() ) {
    my $title = $quake->title();
    my $place = substr($title, 8);
    my $magnitude = substr($title, 2,3);
    my $id = $quake->get( "id");    
    my $update = $quake->get( "updated" );
    my $location = $quake->get( "georss:point");
    print "Magnitude ", $magnitude, " about ", $place, "\n";
    print "id is $id, updated at $update, georss:point is $location \n";
}