#! /usr/bin/perl
# Copyright (C) 2006, Randy Dunlap.

# read stdin, drop non-author: lines, count/sum/tally author: lines by
# each author after sanitizing author-name somewhat.
#
# optionally print out in author-name (-a) alpha order
# or in numeric/count (-n) order (low-to-high)
# or in numeric/count (-m) order (high-to-low) ("max" first)

# hash for author names:
my %authors;
my $auth;
my $sortby;

sub usage()
{
	print "usage: authorcount [-a | -n | -m] < git.log.lines\n";
	exit(1);
}

$sortby = $ARGV[0];
if (($sortby ne "") && ($sortby ne "-a") && ($sortby ne "-n") &&
    ($sortby ne "-m"))
{
	print "Invalid sort option: $sortby\n";
	usage();
}

READIN: while ($line = <STDIN>)
{
	chomp $line;
	next READIN if $line !~ /Author:/;

	$auth = $line;
	$auth =~ s/Author: //;
	$auth =~ s/<.*>//;

	$authors{$auth}++;

} # end READIN

sub byvalue
{
	$authors{$a} <=> $authors{$b};
}

# optionally sort by author name or author counts
# print out the tally array

if ($sortby eq "-a")
{
	foreach $auth (sort keys %authors)
	{
		print "$auth: $authors{$auth}\n";
	}
}
elsif ($sortby eq "-n")
{
	foreach $auth (sort byvalue keys %authors)
	{
		print "$auth: $authors{$auth}\n";
	}
}
elsif ($sortby eq "-m")
{
	foreach $auth (reverse sort byvalue keys %authors)
	{
		print "$auth: $authors{$auth}\n";
	}
}
else # no sort, just hash order
{
	while (($auth, $count) = each(%authors))
	{
		print "$auth: $count\n";
	}
}