#!/usr/bin/perl -w

use strict;
use Getopt::Std;
use File::Basename qw(basename dirname);

our ($opt_h, $opt_n, $opt_s);
getopts('hns');

$opt_h && usage();

sub usage {
        print STDERR "Usage: ${\basename $0} [-h] [-n] [-s] < <log_data>\n";
        exit(1);
}

my (%mailmap);
my (%email);
my (%map);
my $pstate = 1;
my $n_records = 0;
my $n_output = 0;

sub shortlog_entry($$) {
        my ($name, $desc) = @_;
        my $key = $name;

        $desc =~ s#/pub/scm/linux/kernel/git/#/.../#g;
        $desc =~ s#\[PATCH\] ##g;

        # store description in array, in email->{desc list} map
        if (exists $map{$key}) {
                # grab ref
                my $obj = $map{$key};

                # add desc to array
                push(@$obj, $desc);
        } else {
                # create new array, containing 1 item
                my @arr = ($desc);

                # store ref to array
                $map{$key} = \@arr;
        }
}

# sort comparison function
sub by_name($$) {
        my ($a, $b) = @_;

        uc($a) cmp uc($b);
}
sub by_nbentries($$) {
        my ($a, $b) = @_;
        my $a_entries = $map{$a};
        my $b_entries = $map{$b};

        @$b_entries - @$a_entries || by_name $a, $b;
}

my $sort_method = $opt_n ? \&by_nbentries : \&by_name;

sub summary_output {
        my ($obj, $num, $key);

        foreach $key (sort $sort_method keys %map) {
                $obj = $map{$key};
                $num = @$obj;
                printf "%s: %u\n", $key, $num;
                $n_output += $num;
        }
}

sub shortlog_output {
        my ($obj, $num, $key, $desc);

        foreach $key (sort $sort_method keys %map) {
                $obj = $map{$key};
                $num = @$obj;

                # output author
                printf "%s (%u):\n", $key, $num;

                # output author's 1-line summaries
                foreach $desc (reverse @$obj) {
                        print "  $desc\n";
                        $n_output++;
                }

                # blank line separating author from next author
                print "\n";
        }
}

sub changelog_input {
        my ($author, $desc);

        while (<>) {
                # get author and email
                if ($pstate == 1) {
                        my ($email);

                        next unless /^[Aa]uthor:?\s*(.*?)\s*<(.*)>/;

                        $n_records++;

                        $author = $1;
                        $email = $2;
                        $desc = undef;

                        # cset author fixups
                        if (exists $mailmap{$email}) {
                                $author = $mailmap{$email};
                        } elsif (exists $mailmap{$author}) {
                                $author = $mailmap{$author};
                        } elsif (!$author) {
                                $author = $email;
                        }
                        $email{$author}{$email}++;
                        $pstate++;
                }

                # skip to blank line
                elsif ($pstate == 2) {
                        next unless /^\s*$/;
                        $pstate++;
                }

                # skip to non-blank line
                elsif ($pstate == 3) {
                        next unless /^\s*?(.*)/;

                        # skip lines that are obviously not
                        # a 1-line cset description
                        next if /^\s*From: /;

                        chomp;
                        $desc = $1;

                        &shortlog_entry($author, $desc);

                        $pstate = 1;
                }
        
                else {
                        die "invalid parse state $pstate";
                }
        }
}

sub read_mailmap {
        my ($fh, $mailmap) = @_;
        while (<$fh>) {
                chomp;
                if (/^([^#].*?)\s*<(.*)>/) {
                        $mailmap->{$2} = $1;
                }
        }
}

sub setup_mailmap {
        read_mailmap(\*DATA, \%mailmap);
        if (-f '.mailmap') {
                my $fh = undef;
                open $fh, '<', '.mailmap';
                read_mailmap($fh, \%mailmap);
                close $fh;
        }
}

sub finalize {
        #print "\n$n_records records parsed.\n";

        if ($n_records != $n_output) {
                die "parse error: input records != output records\n";
        }
        if (0) {
                for my $author (sort keys %email) {
                        my $e = $email{$author};
                        for my $email (sort keys %$e) {
                                print STDERR "$author <$email>\n";
                        }
                }
        }
}

&setup_mailmap;
&changelog_input;
$opt_s ? &summary_output : &shortlog_output;
&finalize;
exit(0);


__DATA__
#
# Even with git, we don't always have name translations.
# So have an email->real name table to translate the
# (hopefully few) missing names
#
Adrian Bunk <bunk@stusta.de>
Andreas Herrmann <aherrman@de.ibm.com>
Andrew Morton <akpm@osdl.org>
Andrew Vasquez <andrew.vasquez@qlogic.com>
Christoph Hellwig <hch@lst.de>
Corey Minyard <minyard@acm.org>
David Woodhouse <dwmw2@shinybook.infradead.org>
Domen Puncer <domen@coderock.org>
Douglas Gilbert <dougg@torque.net>
Ed L Cashin <ecashin@coraid.com>
Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Felix Moeller <felix@derklecks.de>
Frank Zago <fzago@systemfabricworks.com>
Greg Kroah-Hartman <gregkh@suse.de>
James Bottomley <jejb@mulgrave.(none)>
James Bottomley <jejb@titanic.il.steeleye.com>
Jeff Garzik <jgarzik@pretzel.yyz.us>
Jens Axboe <axboe@suse.de>
Kay Sievers <kay.sievers@vrfy.org>
Mitesh shah <mshah@teja.com>
Morten Welinder <terra@gnome.org>
Morten Welinder <welinder@anemone.rentec.com>
Morten Welinder <welinder@darter.rentec.com>
Morten Welinder <welinder@troll.com>
Nguyen Anh Quynh <aquynh@gmail.com>
Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Peter A Jonsson <pj@ludd.ltu.se>
Ralf Wildenhues <Ralf.Wildenhues@gmx.de>
Rudolf Marek <R.Marek@sh.cvut.cz>
Rui Saraiva <rmps@joel.ist.utl.pt>
Sachin P Sant <ssant@in.ibm.com>
Santtu Hyrkk\e,Av\e(B <santtu.hyrkko@gmail.com>
Simon Kelley <simon@thekelleys.org.uk>
Tejun Heo <htejun@gmail.com>
Tony Luck <tony.luck@intel.com>