# important_changes.pl - This script prints important changes in Sympa since last install
# It is based on the NEWS ***** entries
# RCS Identication ; $Revision: 4868 $ ; $Date: 2008-03-03 17:54:09 +0100 (lun, 03 mar 2008) $ 
#
# Sympa - SYsteme de Multi-Postage Automatique
# Copyright (c) 1997, 1998, 1999, 2000, 2001 Comite Reseau des Universites
# Copyright (c) 1997,1998, 1999 Institut Pasteur & Christophe Wolfhugel
#
# 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, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

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

my ($first_install, $current_version, $previous_version);

$current_version = $ENV{'SYMPA_VERSION'};

unless ($current_version) {
    print STDERR "Could not get current Sympa version\n";
    exit -1;
}

## Get previous installed version of Sympa
unless (open VERSION, "$ENV{'DESTDIR'}$ENV{'BINDIR'}/Version.pm") {
    print STDERR "Could not find previous install of Sympa ; assuming first install\n";
    exit 0;
}

unless ($first_install) {
    while (<VERSION>) {
	if (/^(our )?\$Version = \'(\S+)\'\;/) {
	    $previous_version = $2;
	    last;
	}
    }
}
close VERSION;

## Create the data_structure.version file if none exists
my $version_file = "$ENV{'ETCDIR'}/data_structure.version";
if ($ENV{'ETCDIR'} && ! -f $version_file) {
    ## Create missing directory
    unless (-d $ENV{'ETCDIR'}) {
	print STDERR "Creating missing directory %s...\n", $ENV{'ETCDIR'};
	unless (mkdir $ENV{'ETCDIR'}, 0770) {
	    print STDERR "Failed to create $ENV{'ETCDIR'} directory : $!\n";
	    exit -1;
	}
    }
    
    print STDERR "Creating missing $version_file\n";
    
    unless (open VFILE, ">$version_file") {
	printf STDERR "Unable to write %s ; sympa.pl needs write access on %s directory : %s\n", $version_file, $ENV{'ETCDIR'}, $!;
	return undef;
    }
    printf VFILE "# This file is automatically created by sympa.pl after installation\n# Unless you know what you are doing, you should not modify it\n";
    if ($previous_version) {
	printf VFILE "%s\n", $previous_version;
    }else { 
	printf VFILE "%s\n", $current_version;
    }
    close VFILE;
}

`chown $ENV{'USER'} $version_file`;
`chgrp $ENV{'GROUP'} $version_file`;

if (($previous_version eq $current_version) ||
    &higher($previous_version,$current_version)){
    exit 0;
}

print "You are upgrading from Sympa $previous_version\nYou should read CAREFULLY the changes listed below ; they might be incompatible changes :\n<RETURN>";
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,$v)
	    ) {
	    last;
	}elsif ($v eq $current_version) {
	    $ok = 1;
	}
    }

    next unless $ok;

    if (/^\*{4}/) {
	print "\n" unless $current;
	$current = 1;
	print;
    }else {
	$current = 0;
    }
    
}
close NOTES;
print "<RETURN>";
my $wait = <STDIN> unless ($ENV{'DESTDIR'}); ## required for package building

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

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

    for $i (0..$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;
}