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package Finance::Bitcoin::Feed;
use strict;
use warnings;
use Mojo::Base 'Mojo::EventEmitter';
use AnyEvent;
use Module::Runtime qw(require_module);
use Carp;
use feature qw(say);
our $VERSION = '0.02';
has 'sites' => sub { [qw(Hitbtc BtcChina CoinSetter LakeBtc)] };
has 'output' => sub {
    sub { shift; say join " ", @_ }
};
sub new {
    my $class = shift;
    my $self  = $class->SUPER::new(@_);
    $self->on( 'output', $self->output );
    return $self;
}
sub run {
    my $self = shift;
    my @sites;
    for my $site_class ( @{ $self->sites } ) {
        $site_class = 'Finance::Bitcoin::Feed::Site::' . $site_class;
        eval { require_module($site_class) }
          || croak("No such module $site_class");
        my $site = $site_class->new;
        $site->on( 'output', sub { shift, $self->emit( 'output', @_ ) } );
        $site->go;
        push @sites, $site;
    }
    AnyEvent->condvar->recv;
}
1;
__END__
HideShow 154 lines of Pod
=head1 NAME
Finance::Bitcoin::Feed - Collect bitcoin real-time price from many sites' streaming data source
=head1 SYNOPSIS
    use Finance::Bitcoin::Feed;
    #default output is to print to the stdout
    Finance::Bitcoin::Feed->new->run();
    # will print output to the stdout:
    # COINSETTER BTCUSD 123.00
     
    #or custom your stdout
    open  my $fh, ">out.txt";
    $fh->autoflush();
    my $feed = Finance::Bitcoin::Feed->new(output => sub{
       my ($self, $site, $currency, $price) = @_;
       print $fh "the price currency $currency on site $site is $price\n";
    });
    # let's go!
    $feed->run();
    #you can also custom which site you want to connect
    Finance::Bitcoin::Feed->new(sites => [qw(LakeBtc)])->go;
=head1 DESCRIPTION
L<Finance::Bitcoin::Feed> is a bitcoin realtime data source which collect real time data source from these sites:
=over 4
=item * L<HitBtc|https://hitbtc.com/api#socketio>
=item * L<BtcChina|http://btcchina.org/websocket-api-market-data-documentation-en>
=item * L<CoinSetter|https://www.coinsetter.com/api/websockets/last>
=item * L<<lakebtc api|https://www.lakebtc.com/s/api>
=back
The default output format to the stdout by this format:
   site_name TIMESTAMP CURRENCY price
For example:
   COINSETTER 1418173081724 BTCUSD 123.00
The unit of timestamp is ms.
You can custom your output by listen on the event L<output> and modify the data it received.
Note the followiing sites doesn't give the timestamp. So the timestamp in the result will be 0:
LakeBtc
=head1 METHODS
This class inherits all methods from L<Mojo::EventEmitter>
=head2 new
This method have two arguments by which you can costumize the behavior of the feed:
=head3 sites
which sites you want to connect. It is in fact the array reference of  module names of Finance::Bitcoin::Feed::Site::*. Now it have 4 modules:
Hitbtc
BtcChina
CoinSetter
LakeBtc
You can also put your own site module under this namespace and added here.
=head3 output
customize the output format by giving this argument a sub reference. It will be bind to the event 'output'. Please rever to the event <output>.
   # you can customize the output by giving argument 'output' to the new methold
    open  my $fh, ">out.txt";
    $fh->autoflush();
    my $feed = Finance::Bitcoin::Feed->new(output => sub{
       my ($self, $site, $timestamp, $currency, $price) = @_;
       print $fh "the price currency $currency on site $site is $price\n";
    });
    # let's go!
    $feed->run();
=head1 EVENTS
This class inherits all events from L<Mojo::EventEmitter> and add the following new ones:
=head2 output
This event has a default subscriber:
   #output to the stdout, the default action:
   $feed->on('output', sub { shift; say join " ", @_ } );
You can customize the output by giving argument 'output' to the new method
    open  my $fh, ">out.txt";
    $fh->autoflush();
    my $feed = Finance::Bitcoin::Feed->new(output => sub{
       my ($self, $site, $timestamp, $currency, $price) = @_;
       print $fh "the price currency $currency on site $site is $price\n";
    });
    # let's go!
    $feed->run();
Or you can bind output directly to the feed to get multi outout or you should unscribe this event first.
    $feed->on('output', sub {....})
The arguments of this event is:
$self: the site class object
timestamp: the timestamp of the data. If no timestamp is given by the site, then the value of it is 0.
sitename: the site class name
price: the price
=head1 DEBUGGING
You can set the FINANCE_BITCOIN_FEED_DEBUG environment variable to get some advanced diagnostics information printed to STDERR.
And these modules use L<Mojo::UserAgent>, you can also open the MOJO_USERAGENT_DEBUG environment variable:
   FINANCE_BITCOIN_FEED_DEBUG=1
   MOJO_USERAGENT_DEBUG=1
=head1 SEE ALSO
L<Mojo::EventEmitter>
L<Finance::Bitcoin::Feed::Site::Hitbtc>
L<Finance::Bitcoin::Feed::Site::BtcChina>
L<Finance::Bitcoin::Feed::Site::CoinSetter>
L<Finance::Bitcoin::Feed::Site::LakeBtc>
=head1 AUTHOR
Chylli  C<< <chylli@binary.com> >>
=head1 COPYRIGHT
Copyright 2014- Binary.com