#! /usr/bin/perl
use strict;
use warnings;
use Encode;
binmode STDOUT, ':utf8';
print "Fetching all historical contributors for CREDITS\n";
my @shas = qx/git log --pretty=oneline --follow CREDITS.txt/;
s/^(\w+).*/$1/ for @shas;
my $contributors = '';
fetch_contributors($_) for @shas;
print "Going back to master\n";
system "git checkout master" and die "git checkout master failed\n";
open my $outf, '>>', 'CREDITS.txt' or die "Can't write CREDITS.txt\n";
binmode $outf, ':utf8';
print $outf "\n$contributors\n";
close $outf;
print "Contributors appended to CREDITS.txt!\n";
sub fetch_contributors {
  my $sha = shift;
  print "Visiting $sha credits.\n";
  system "git checkout $sha" and die "git checkout $sha failed\n";
  $contributors .= credits_names();
}
sub find_credits {
  my @tests = grep(-f, ('CREDITS.txt', 'CREDITS'));
  die "Cannot find CREDITS file\n" unless @tests;
  return $tests[0];
}
sub decodeText {
  my $bytes = shift;
  eval {
    $bytes = decode('utf-8', $bytes, 1);
    return $bytes;
  };
  eval {
    $bytes = decode('iso-8859-1', $bytes, 1);
    return $bytes;
  };
  $bytes
}
sub credits_names {
  my $file = find_credits();
  open my $inf, '<', $file or die "Can't read $file: $!\n";
  binmode $inf;
  my @lines = <$inf>;
  close $inf;
  my $res = '';
  my $incontributors;
  for (@lines) {
    chomp;
    $_ = decodeText($_);
    $_ .= "\n";
    $res .= $_ if $incontributors && /\S/;
    $incontributors = 1 if !$incontributors && /contributed.*:\s*$/;
  }
  $res
}

Warwick Allison              R. Dan Henry              nyra
Juha Arpiainen               Brendan Hickey            Dylan O'Donnell
Roy Axenov                   Benoit Hudson             Stefan O'Rear
Max Bane                     Iainuki                   Yuuma Oohara
Bill Beher                   Ilyak                     Erik Piper
Alexander Beisig             Mitsuhiro Itakura         Lemuel Pitkin
Stu Black                    Mikko Juola               Derek Ray
Erik Inge Bolsø              Jarmo Kielosto            Remsleep
                                                       Will Rogers
Peter Borgmann               Kornel Kisielewicz        David Rose
Jude Brown                   Daniel Klein              Sebastian Salman
Trent W. Buck                Vambola Kotkas            Brett Scarborough
Terje Bø                     Vsevolod Kozlov           Darshan Shaligram
Aaron Curtis                 Ryan Kusnery              Robert Shimmin
Denzi                        Jukka Kuusisto            Sigurd
Rachel Elizabeth Dillon      Maciej Lapinski           Edgar Simo
Mike Drinen                  Jordan Lewis              Solf
Kieron Dunbar                Icy Lich                  Johan Strandell
Micha Elsner                 Jesse Luehrs              Roman Sêk
Christopher Evenstar         Markus Maier              Marc H. Thoben
Ben Goetter                  Arien Malec               Matt Titus
Rob Grant                    Neil 'Mu' Middleton       Steven Wheeler
John Greenberg               Shawn M Moore             Jeremey Wilson
GreyKnight                   Eva Myers                 Yelve Yakut
Shayne Halvorson             Wille Mäntylä             Zooko
Ciaran Hamilton              Onia Ninara
Chris Hamons                 Erkki Nurmi

Warwick Allison              R. Dan Henry              Mattias Nyberg
Juha Arpiainen               Brendan Hickey            nyra
Roy Axenov                   Benoit Hudson             Dylan O'Donnell
Max Bane                     Iainuki                   Stefan O'Rear
Bill Beher                   Ilyak                     Yuuma Oohara
Alexander Beisig             Mitsuhiro Itakura         Pedro
Stu Black                    Mikko Juola               Erik Piper
Erik Inge Bolsø              Jarmo Kielosto            Lemuel Pitkin
Peter Borgmann               Kornel Kisielewicz        Derek Ray
Jude Brown                   Daniel Klein              Remsleep
Trent W. Buck                Vambola Kotkas            Will Rogers
Terje Bø                     Vsevolod Kozlov           David Rose
Aaron Curtis                 Ryan Kusnery              Sebastian Salman
Denzi                        Jukka Kuusisto            Brett Scarborough
Rachel Elizabeth Dillon      Maciej Lapinski           Darshan Shaligram
Mike Drinen                  Jordan Lewis              Robert Shimmin
Kieron Dunbar                Icy Lich                  Sigurd
Micha Elsner                 Jesse Luehrs              Edgar Simo
Christopher Evenstar         Markus Maier              Solf
Ben Goetter                  Arien Malec               Johan Strandell
Rob Grant                    Paul Maloney              Roman Sêk
John Greenberg               Neil 'Mu' Middleton       Marc H. Thoben
GreyKnight                   Shawn M Moore             Matt Titus
Joshua Gross                 Eva Myers                 Steven Wheeler
Shayne Halvorson             Wille Mäntylä             Jeremey Wilson
Ciaran Hamilton              Onia Ninara               Yelve Yakut
Chris Hamons                 Erkki Nurmi               Zooko