#!/usr/bin/perl
# Catch all in-source GPL2/3 license declarations and convert
# them to AGPL.
#
# You expected this to be using diff & patch? Well, the source
# files have all sorts of different commenting and indentation
# styles, not speaking of typos and failed uses of search and
# replace, that an attempt in using the patch(1) tool would fail
# miserably. This script instead is based on my rgrep from 1998.
# Keeping it here as it may be useful to other projects under-
# going the same pains. It is forbidden to use this script to
# convert AGPL code back to less strict licensing. Haha, just
# kidding.
#
#	-symlynX

use File::Find;
$|=1;
# Recurse into current or given directories
find(\&wanted, $#ARGV >= 0 ? @ARGV : '.');
print STDERR "\n";
exit;


sub wanted {
	my $name = $File::Find::name;
	($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size,$atime,$mtime,$ctime)
		= lstat;
	return $File::Find::prune = 1 if /^(CVS|\.git|\.svn)$/;
	# Nicer if you 'make distclean' first
	return if /\.(o|pdf)$/i;
	return if -d _ or -l _;
	return if /afferify/;	# Don't apply this to itself ;)
				# No.. i didn't do it.. just being careful ;) ;)
#	return unless -T _;	# We don't have binaries in the repo, do we?

	# We need the default variable '$_' for more important duties.
	my $f = $_;

	if (sysopen(I, $f, O_RDONLY)) {
		$_ = &slurp(*I);
		close I;
		# Debugging: What's inside the file we just read?
#		print STDERR '> ', $_;

		# Good idea to have the text start with "GNUnet" rather than "This program"
		if ( s#GNUnet is free software; you can redistribute it and/or modify it under the#GNUnet is free software: you can redistribute it and/or modify it# ) {
		    # Whoever had the idea of reformatting the GPL license text...
		    print STDERR "\nTrying wide style on $name\t";

		    # Most important thing to know in order to be able
		    # to read perl code: if regexps appear without any
		    # context, it means they are applied to the default
		    # variable being '$_'.
		    return unless s#terms of the GNU General Public License as published by the Free Software#under the terms of the GNU General Public License as published#;
		    return unless s#^(\W*\s+)Foundation; either version \d, or \(at your option\) any later version\.#\1by the Free Software Foundation, either version 3 of the License,\n\1or (at your option) any later version.#m;
		    return unless s#GNUnet is distributed in the hope that it will be useful, but WITHOUT ANY#GNUnet is distributed in the hope that it will be useful, but#;
		    return unless s#WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR#WITHOUT ANY WARRANTY; without even the implied warranty of#;
		    return unless s#^(\W*\s+)A PARTICULAR PURPOSE.  See the GNU General Public License for more details.#\1MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU\n\1Affero General Public License for more details.#m;
		    return unless s#^\W*\n\W*\s+You should have received a copy of the GNU General Public License along with\n\W*\s+GNUnet. see the file COPYING\.  If not, .* see\s*\W*\s+<http://www.gnu.org/licenses/>\n##m;
		} else {
		    # If this string is not in the file, leave it alone.
		    return unless s#GNUnet is free software; you can redistribute it and/or modify#GNUnet is free software: you can redistribute it and/or modify it#;
		    print STDERR "\nTrying regular style on $name\t";

		    # Patterns are designed to also match some typos and substitutions.
		    return unless s#it under the terms of the GNU General Public Lice\w+ as published#under the terms of the GNU General Public License as published#;
		    return unless s#by the Free Software Foundation; either version \d, or \(at your#by the Free Software Foundation, either version 3 of the License,#;
		    return unless s#option\) any later version\.#or (at your option) any later version.#;
		    return unless s#General Public Lice\w+ for more details\.#Affero General Public License for more details.#;
		    return unless s#^\W*\n\W*\s+You should have received a copy of the GNU General Public Lice\w+\n\W*\s+along with GNUnet. see the file COPYING\.  If not, write to the\n\W*\s+Free Software Foundation, Inc\., (51 Franklin Street, Fifth Floor|59 Tem ?ple Place - Suite 330),\n\W*\s+Boston, MA 0211\d-130\d, USA\.\n##m;
		}
		print STDERR "OK";

		# We directly overwrite the original file in the
		# assumption that we're in a healthy revertible git.
		open(O, '>', $f) or die "Cannot overwrite $f";
		# Imagine, I could have left out $_ here... ;)
		print O $_;
		close O;
	} else {
		die "Cannot access $name";
	}
}

# Reads a file from a stream into a variable all at once:
sub slurp {
	# Perl sure gets clunky here
	local(*IN) = @_;
	local($save) = $/;
	undef $/;
	local($data) = <IN>;
	$/ = $save;
	return $data;
}