#!/usr/bin/perl -w

use strict;
use warnings;

use Getopt::Long;
use HTML::Entities;
use LWP;
use XML::RSSLite;


#
#  Configuration variables
#
my %CONFIG;


#
#  Parse arguments.
#
parseCommandLineArguments();


#
#  Validate any arguments.
#
validateCommandLineArguments();


#
#  Fetch the feed.
#
my $content = fetchRSSFeed( $CONFIG{ 'feed' } );


#
# Parse the feed
#
my %rssHash;
parseRSS( \%rssHash, \$content );


#
#  Now import
#
processEntries(%rssHash);


#
#  All done.
#



=begin doc

  Parse the command line arguments, if any.

=end doc

=cut

sub parseCommandLineArguments
{
    if (
        !GetOptions(

                     "feed=s",     \$CONFIG{ 'feed' },
                     "output=s",   \$CONFIG{ 'output' },
                     "sequential", \$CONFIG{ 'sequential' },
        )
      )
    {
        exit;
    }
}



=begin doc

  Ensure we received the arguments we need, and that
 those arguments look OK.

=end doc

=cut

sub validateCommandLineArguments
{

    #
    #  We need an output dir
    #
    if ( !$CONFIG{ 'output' } )
    {
        print "Output directory is mandatory.\n";
        print "Please specificy via --output=...\n";
        exit;
    }
    if ( !-d $CONFIG{ 'output' } )
    {
        print
"Specified output directory [$CONFIG{'output'}] is not a directory!\n";
        exit;
    }

    #
    #  We need a feed
    #
    if ( !$CONFIG{ 'feed' } )
    {
        print "Please specify a feed to import, via --feed=http:/....\n";
        exit;
    }

}



=begin doc

  Fetch the remote RSS feed.

=end doc

=cut

sub fetchRSSFeed
{
    my ($uri) = (@_);

    my $ua = LWP::UserAgent->new();
    $ua->timeout(10);
    $ua->agent('chronicle-importer');

    my $response = $ua->get($uri);

    if ( $response->is_success )
    {
        return ( $response->content() );
    }
    else
    {
        print "Failed to fetch feed: $uri\n";
        print "\n";
        print $response->message() . "\n";
        exit;
    }

}



=begin doc

  Iterate over the items in our feed and write each one out to a
 single file.

=end doc

=cut

sub processEntries
{
    my (%entries) = (@_);

    my $count = 1;

    foreach my $item ( @{ $rssHash{ 'item' } } )
    {

        #
        #  Get details from the feed.
        #
        my $title = $item->{ 'title' } || "no title";
        my $date = $item->{ 'pubDate' } || $item->{ 'dc:date' } || undef;
        my $body =
             $item->{ 'description' }
          || $item->{ 'content:encoded' }
          || undef;
        my $filename;


        #
        #  Build up a suitable filename.
        #
        if ( $CONFIG{ 'sequential' } )
        {
            $filename = $count . ".txt";
        }
        else
        {
            $filename = $title;
            $filename =~ s/[^a-z0-9]/_/gi;
            $filename .= ".txt";

        }

        #
        #  Naive expansion.
        #
        if ( $body =~ m/</ )
        {
            $body = decode_entities($body);
        }
        $filename = $CONFIG{ 'output' } . "/" . $filename;
        open( OUTPUT, ">", $filename )
          or die "Failed to write to $filename - $!";
        print OUTPUT <<EOF;
Title: $title
Date: $date

$body
EOF
        close(OUTPUT);
        $count += 1;
    }

}