#!/usr/bin/perl
# 3456789#123456789#123456789#123456789#123456789#123456789#123456789#123456789#
# bcinflation.pl 20101228 jeffrey paul <sneak@datavibe.net> 
# 5539 AD00 DE4C 42F3 AFE1  1575 0524 43F4 DF2A 55C2  # please sign!

use strict;
use warnings qw( all );
use LWP::Simple;
use Data::Dumper;
use HTML::Strip;
use DateTime;

# thanks to nullvoid for historical block data
# that's actually mizerydearia, the witcoin guy
my $historyurl = 'http://nullvoid.org/bitcoin/difficultiez.php';
my $growthfactor = 1.0;

main();

sub main {
    my $hist = fetch_history_data() or die "unable to fetch history!";
    my $block = 0;
    my $totalbc = 0;
    my $perblock = 50;
    my $at = 1231006505; # block zero timestamp
    while ($block < 1500000) { # arbitrary
        $block++;
        $perblock /= 2 unless $block % 210000;
        $at += 60*10/$growthfactor; # estimate block timestamp
        # replace with real data if we have it:
        $at = $hist->{$block}{'ts'} if exists($hist->{$block});
        $totalbc += $perblock;
        #if ($block == 210000) {
        #    print ts2nice($at);
        #    die;
        #}
        unless($block % 21000) {
            print ts2nice($at) . ",";
            print $block . ",";
            print $perblock . ",";
            print $totalbc. ",";
            if (exists($hist->{$block})) {
                print $hist->{$block}{'difficulty'};
            }
            print ",\n";
        }
    }
}

sub ts2nice { return DateTime->from_epoch( epoch => shift() )->ymd; }

sub fetch_history_data {
    my $raw = get($historyurl) or die "derp: $!";

    my $clean = HTML::Strip->new()->parse($raw);
    $clean =~ s/Block/\nBlock/g;
    my $out = {};
    foreach my $l (split(/\n+/,$clean)) {
        next unless $l =~ /^Block\s+([0-9]+)\s+was.*at\s+([0-9]+).*Difficulty\:\s+([0-9\.]{3,10}).*$/;
        $out->{$1}{'ts'} = $2;    
        $out->{$1}{'difficulty'} = $3;    
    }
    return unless $out->{135072}; # latest diffchange block
    return $out;
}

1;
__END__