#!/usr/local/bin/perl -w

use strict;
#use Cwd;
use File::Copy;
#use File::Basename;
#use File::Find;
use Getopt::Std;

# This script updated (a) file(s) to the new style header.
# The precondition is that is has a valid (old) header.

sub usage()
{
    print STDERR<<"EOF";
usage:
  $0 [-h] [-q owner] file1 ...

    -h show this message and quit
    -q owner (default: LGPL,
              otherwise it's QPL, with choices among :
              UU, INRIA, ETHZ, FUB, MPI, RISC, TAU, TRIER, HW,
              which will be expanded)
EOF
}

my $lgpl_owner="Utrecht University (The Netherlands),
// ETH Zurich (Switzerland), Freie Universitaet Berlin (Germany),
// INRIA Sophia-Antipolis (France), Martin-Luther-University Halle-Wittenberg
// (Germany), Max-Planck-Institute Saarbruecken (Germany), RISC Linz (Austria),
// and Tel-Aviv University (Israel).";

my %qpl_owners=("UU"    => "Utrecht University (The Netherlands)",
                "INRIA" => "INRIA Sophia-Antipolis (France)",
                "ETHZ"  => "ETH Zurich (Switzerland)",
                "FUB"   => "Freie Universitaet Berlin (Germany)",
                "MPI"   => "Max-Planck-Institute Saarbruecken (Germany)",
                "RISC"  => "RISC Linz (Austria)",
                "TAU"   => "Tel-Aviv University (Israel)",
                "TRIER" => "University of Trier (Germany)",
                "HW"    => "Martin-Luther-University Halle-Wittenberg (Germany)"
);

sub gjmove($$)
{
    return 1 if rename($_[0], $_[1] );
    return (system('mv', "$_[0]", "$_[1]") == 0);
}

#----------------------------------------------------------------#
#                     initialization                             #
#----------------------------------------------------------------#

my $TEMPFILE;


sub print_qpl_license()
{
    print TEMPFILE <<'END_OF_LICENSE';
// This file is part of CGAL (www.cgal.org); you may redistribute it under
// the terms of the Q Public License version 1.0.
// See the file LICENSE.QPL distributed with CGAL.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
END_OF_LICENSE
}

sub print_lgpl_license()
{
    print TEMPFILE <<'END_OF_LICENSE';
// This file is part of CGAL (www.cgal.org); you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; version 2.1 of the License.
// See the file LICENSE.LGPL distributed with CGAL.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
END_OF_LICENSE
}

#----------------------------------------------------------------#
#                     check_and_update_2                         #
#----------------------------------------------------------------#

sub check_and_update_2($$)
{
    my ($filename, $owner) = @_;
    my $header_position = 1;
# 1:before header; 2: in first part; 3: in second part 4: after header.

    my $text_before_header = 0;
    while ( <SOURCE_FILE> ) {
	if ( m|^\s*//\s*={10,}\s*$| ) {
	    $header_position = 2;
	    last;
	}
	if ( $_ !~ m|^\s*$| ) {
	    $text_before_header = 1;
	}
	print TEMPFILE $_;
    }
    if ($header_position != 2) {
	print FILE_CHECKS "$filename has no header.\n";
	return 0;
    }
    if ($text_before_header) {
	print FILE_CHECKS "$filename has text before the header.\n";
    }
    $_ = <SOURCE_FILE>;
    $_ = <SOURCE_FILE> while (m|^\s*//\s*$|);
    if ($_ !~ m<^\s*//\s*Copyright\s*\(c\)\s*\d{4}([-,]\s?\d{4})*\s+(t|T)he CGAL Consortium\s*$> ) {
	print FILE_CHECKS "$filename has no valid copyright notice.\n";
	return 0;
    }

    if (defined($owner)) {
      # QPL case.
      my $qpl_owner=$qpl_owners{$owner};
      s/(t|T)he CGAL Consortium\s*$/ $qpl_owner/;
      print TEMPFILE $_;
      print TEMPFILE ".\n// All rights reserved.\n//\n";
      print_qpl_license;
    } else {
      # LGPL case.
      s/(t|T)he CGAL Consortium\s*$/ $lgpl_owner/;
      print TEMPFILE $_;
      print TEMPFILE "  All rights reserved.\n//\n";
      print_lgpl_license;
    }

    print TEMPFILE <<'END_OF_DISCLAIMER';
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL$
// $Id$
// 
//
END_OF_DISCLAIMER

    my ($authors_seen) = (0);
    while ( <SOURCE_FILE> ) {
	next if ($_ !~ m|^\s*//| );
	++$authors_seen if m<^\s*//\s*author(s|\(s\))?\s*:>;
	if ($authors_seen > 0) {
	  if (m<^\s*//\s*(coordinator|package|release|maintainer)(s|\(s\))?\s*:>) {
          --$authors_seen;
          } else {
            if (! m|//\s*$|) {
              s/author/Author/;
              print TEMPFILE $_; # we keep the authors
            }
          }
        }
        last if /======/;
    }

    while ( <SOURCE_FILE> ) {
	print TEMPFILE $_;
    }

    return 0;
}

sub check_and_update_file($$)
{
    my ($filename, $owner) = @_;
    open SOURCE_FILE, "<$filename" || die "Error opening $filename: $!\n";
    open TEMPFILE, ">$TEMPFILE" || die;
    check_and_update_2($filename, $owner);
    close SOURCE_FILE || die "Error closing $filename: $!";
    close TEMPFILE || die "Error closing temporary file: $!\n";
    gjmove($TEMPFILE, $filename )
    || warn "Could not update file $filename\n";
}


#$::PARENT_DIR=cwd();

sub main()
{
    umask(002);

    getopts('hq:');
    if ($::opt_h ) {
	usage;
	return;
    }
    $::opt_h = 0;

    if ($::opt_q and not $qpl_owners{$::opt_q}) {
      print "Unknown QPL owner\n";
      return;
    }

    $TEMPFILE="tmp.$$";

    open FILE_CHECKS, ">-";
    my $filename;
    foreach $filename (@ARGV) {
        print "new_headers acting on $filename.\n";
	check_and_update_file($filename, $::opt_q);
    }
    close  FILE_CHECKS;
}

main;