#!/usr/bin/perl 

# Copyright 2010 Catalyst IT Ltd.
#
# This file is part of Koha.
#
# Koha 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 3 of the License, or
# (at your option) any later version.
#
# Koha 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 Koha; if not, see <http://www.gnu.org/licenses>.

# Written by Robin Sheat <robin@catalyst.net.nz> and
#   Srdjan Jankovic <srdjan@catalyst.net.nz>
# Based on an sh version by Lars Wirzenius.

use strict;
use warnings;

use Getopt::Long;
use POSIX qw/strftime/;

my $buildresult;
my $distribution='squeeze-dev';
my $git_checks='all';
my $version='3.21~git';
my $auto_version=1;
my $need_help;
my $debug;

GetOptions(
    'buildresult|r=s'   => \$buildresult,
    'distribution|D=s'  => \$distribution,
    'git-checks|g=s'    => \$git_checks,
    'version|v=s'       => \$version,
    'autoversion!'      => \$auto_version,
    'help|h'            => \$need_help,
    'debug|d'           => \$debug,
);

help_and_exit() if $need_help;


sub sys_command_output {
    my ($command) = @_;

    print "$command\n" if $debug;
    my $command_output;
    open($command_output, "-|", "$command ")
      or die qq{Cannot execute "$command": $!"};
    return map { chomp; $_ } <$command_output>;
}

sub sys_command_output_screen {
    my ($command) = @_;

    print "$command\n" if $debug;
    system($command) == 0 or die "Command '$command' returns an error ($?)\n";
}

sub everything_is_committed {
    my $filter;
    for ($git_checks) {
        $_ eq "none"
          and return 1;

        $_ eq "modified"
          and $filter = "no",
              last;

        $_ eq "all"
          and $filter = "normal",
              last;

	    help_and_exit("$0: --git-checks/-g must be one of 'all', 'modified', or 'none'");
    }
    my $has_changes = grep /^xxx/, sys_command_output("git status --porcelain -u${filter}");

    return !$has_changes;
}

sub help_and_exit {
	my $msg = shift;
	if ($msg) {
    	print "$msg\n\n";
    }
    print <<EOH;
This builds Koha deb packages, from a git snapshot. It's not suitable for
making upstreamable verions, but handy for your own local packages.

Options:
    --buildresult, -r
        the location that the resulting .deb, .changes, etc. will be placed in.
        Default is whatever pdebuild uses.
    --distribution, -D
        the distribution value to set in the changelog when editing it. Default
        is 'squeeze-dev'.
    --git-checks, -g
        what level of git checks are run to determine if the working copy is
        clean enough. One of 'all' (any changes are bad), 'modified' (only
        tracked files with untracked changes will cause an error), and 'none'
        (checking git status is skipped totally.) Default is 'all'.
    --version, -v
        the version string for the resulting package. Default is '$version'.
    --(no)autoversion
        whether or not to use the date and git commit ID in the version value.
        Default is to include it.
    --debug, -d
EOH
    exit;
}

sub latest_sha1 {
    return sys_command_output("git rev-parse --short=8 HEAD");
}

sub adjust_debian_changelog {
    my ($newversion) = @_;

    sys_command_output( qq{dch --force-distribution -D "$distribution" -v "$newversion" "Building git snapshot."} );
    sys_command_output( qq{dch -r "Building git snapshot."} );
}

sub reset_debian_changelog {
    sys_command_output( qq{git checkout -- debian/changelog} );
}

sub build_package {
    my ($newversion) = @_;
    sys_command_output( qq{git archive --format=tar --prefix="koha-$newversion/" HEAD | gzip -9 > "../koha_$newversion.tar.gz"} );

    my $pdebuildopts = $buildresult ? "--buildresult $buildresult" : "";
    sys_command_output_screen( "pdebuild $pdebuildopts" );
}

everything_is_committed() or die "cannot build: uncommited changes";

my $newversion = $auto_version
  ? sprintf ('%s%s.%s', $version, strftime("+%Y%m%d%H%M%S", localtime), latest_sha1())
  : $version;

adjust_debian_changelog( $newversion );
build_package( $newversion );
reset_debian_changelog();