#!/usr/local/bin/perl
# vim:sts=4 sw=4

use strict;
use warnings;
use 5.024;

sub short_ref {
    my ($ref) = @_;
    $ref =~ s{refs/heads/}{}oms;
    return $ref;
}

my $push_option_count = $ENV{GIT_PUSH_OPTION_COUNT};
for (my $i = 0; $i < $push_option_count; ++$i) {
    exit 0 if $ENV{"GIT_PUSH_OPTION_${i}"} eq "unsupported-quarterly";
}

my @quarterlies;

for (qx{git show-ref --heads}) {
    chomp;
    my ($hash, $ref) = split / /;
    next if $ref !~ m{refs/heads/\d\d\d\dQ\d\z}oms;
    push @quarterlies, $ref;
}

@quarterlies = sort @quarterlies;

my $latest = $quarterlies[-1];

foreach (<STDIN>) {
    chomp;
    my ($old, $new, $ref) = split / /;

    next if $ref !~ m{^refs/heads/20\d\dQ\d\z}oms;
    next if $ref eq $latest;

    die "\n================================================================\n" .
      "$ENV{GL_USER}, you are pushing a commit to ${\(short_ref($ref))} which is not\n" .
      "the latest quarterly branch. The latest is ${\(short_ref($latest))}.\n" .
      "\n" .
      "Please check that you really mean to do this, and if you do, use:\n" .
      "\tgit push --push-option=unsupported-quarterly\n" .
      "================================================================\n"
}

exit 0;