# important_changes.pl - This script prints important changes in Sympa since last install
# It is based on the NEWS ***** entries
# RCS Identication ; $Revision: 10083 $ ; $Date: 2014-01-01 01:12:12 +0100 (mer. 01 janv. 2014) $ 
#
# Sympa - SYsteme de Multi-Postage Automatique
#
# Copyright (c) 1997, 1998, 1999 Institut Pasteur & Christophe Wolfhugel
# Copyright (c) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
# 2006, 2007, 2008, 2009, 2010, 2011 Comite Reseau des Universites
# Copyright (c) 2011, 2012, 2013, 2014 GIP RENATER
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

## Print important changes in Sympa since last install
## It is based on the NEWS ***** entries

use strict;
use Getopt::Long;

my %options;
GetOptions(
    \%options,
    'current=s',
    'previous=s',
);

die "no current given version, aborting" unless $options{current};

if (!$options{previous}) {
    print STDERR "No previous version given, assuming first installation";
    exit 0;
}

my $previous_version = $options{previous};
my $current_version = $options{current};

# exit immediatly if previous version is higher or equal
if (($previous_version eq $current_version) ||
    &higher($previous_version,$current_version)){
    exit 0;
}

print <<EOF;
You are upgrading from Sympa $previous_version
You should read CAREFULLY the changes listed below
They might be incompatible changes:
<RETURN>
EOF

my $wait = <STDIN>;

## Extracting Important changes from release notes
open NOTES, 'NEWS';
my ($current, $ok);
while (<NOTES>) {
    if (/^([\w_.]+)\s/) {
	my $v = $1;
	if ($v eq $previous_version  || 
	    &higher($previous_version,$v)
	    ) {
	    last;
	}else{
	    $ok = 1;
	}
    }

    next unless $ok;

    if (/^\*{4}/) {
	print "\n" unless $current;
	$current = 1;
	print;
    }else {
	$current = 0;
    }
    
}
close NOTES;
print "<RETURN>";
my $wait = <STDIN>;

sub higher {
    my ($v1, $v2) = @_;

    my @tab1 = split /\./,$v1;
    my @tab2 = split /\./,$v2;
    
    
    my $max = $#tab1;
    $max = $#tab2 if ($#tab2 > $#tab1);

    for my $i (0..$max) {
    
        if ($tab1[0] =~ /^(\d*)a$/) {
            $tab1[0] = $1 - 0.5;
        }elsif ($tab1[0] =~ /^(\d*)b$/) {
            $tab1[0] = $1 - 0.25;
        }

        if ($tab2[0] =~ /^(\d*)a$/) {
            $tab2[0] = $1 - 0.5;
        }elsif ($tab2[0] =~ /^(\d*)b$/) {
            $tab2[0] = $1 - 0.25;
        }

        if ($tab1[0] eq $tab2[0]) {
            #printf "\t%s = %s\n",$tab1[0],$tab2[0];
            shift @tab1;
            shift @tab2;
            next;
        }
        return ($tab1[0] > $tab2[0]);
    }

    return 0;
}
