smartmktag

#! /usr/bin/perl

use strict;
use File::Basename;

sub get_head_rev
{
    my ($input, $rev);
    my $dir = $_[0];
    open($input, "git -C $dir log -1 |") or die "Failed to get HEAD revision: $!";
    while (<$input>) {
	chomp;
	if (m/^commit\s+/) {
	    s/^commit\s//;
	    $rev=$_;
	}
    }
    close $input;
    return $rev;
}

sub extract_spec_version
{
    my ($input, $version, $release);
    my $dir = $_[0];
    my $fn = $_[1];
    my $rev = $_[2];
    open($input, "git -C $dir show $rev:$fn |")
	 or "Failed to run git -C $dir show $rev:$fn: $!";
    while (<$input>) {
	chomp;
	if (m/\s*Version:/) {
	    s/\s*Version:\s*//;
	    s/\s*$//;
	    $version = $_;
	} elsif (m/\s*Release:/) {
	    s/\s*Release:\s*//;
	    s/\%.*//;
	    $release = $_;
	}
    }
    close $input;
    defined($version) and defined($release)
	or die "Failed to extract version and release from $dir/$fn for revision $rev";
    return "${version}-${release}";
}

sub git_config_get
{
    my $dir = shift;
    my $cfgname = shift;
    my ($input, $retval);
    open($input, "git config --get $cfgname |")
	or die "Failed to run 'git config --get': $!";
    while (<$input>) {
	chomp;
	$retval = $_;
	last;
    }
    close $input;
    return $retval
}

sub get_revison_and_version
{
    my $input;
    my $dir = shift;
    my $count = shift;
    if ($count == 0) {
	$count = 10;
    }
    my @spec_files = glob("$dir/smartmet-*.spec");
    scalar @spec_files == 1 or die "Exactly one SPEC file expected in $dir";

    my $fn = basename($spec_files[0]);
    print "Found spec file $fn\n";
    open($input, "git -C $dir log -$count $fn |")
	or die "Failed to get git history of $fn: $!";
    my ($rev, $version);
    $version = undef;

    while (<$input>) {
	if (m/^commit/) {
	    chomp;
	    s/^commit\s+//;
	    my $curr_rev = $_;
	    my $curr_ver = extract_spec_version($dir, $fn, $curr_rev);
	    if (!$version) {
		$rev = $curr_rev;
		$version = $curr_ver;
	    } elsif ($version eq $curr_ver) {
		$rev = $curr_rev;
	    } else {
		last;
	    }
	}
    }
    close $input;
    return ($rev, $version);
}

sub create_tag_if_needed
{
    my $input;
    my $dir = shift;
    my ($rev, $ver_full) = get_revison_and_version($dir, 10);
    print "Latest version change to $ver_full in SPEC file found at revision $rev\n";
    open ($input, "git tag -l $ver_full |") or die "Failed to list tags";
    my @tag_list = <$input>;
    close $input;
    if (scalar @tag_list == 0) {
        my $head = get_head_rev $dir;
        print "Creating tag $ver_full for commit $rev\n";
        system("git -C $dir tag $ver_full $rev");
    } else {
        print "Tag $ver_full already exists\n"
    }
}

#create_new_version(".", "Rebuilt due to joy");
create_tag_if_needed (".");