#! /usr/bin/perl -w

use strict;
use POSIX qw(tmpnam);

my $pkgfile = $ARGV[0];
die unless defined $pkgfile;

my $tmpdir;
do { $tmpdir = tmpnam(); }
until mkdir $tmpdir, 0777;

# !!! remove tmpdir on exit

print "Unpacking $pkgfile in $tmpdir...\n";
system "bunzip2 < $pkgfile | (cd $tmpdir && tar xf -)";
die if $?;

print "This package contains the following derivations:\n";
system "nix-env -qasf $tmpdir/default.nix";
die if $?;

print "Do you wish to install these (Y/N)? ";
my $reply = <STDIN>;
chomp $reply;
exit if (!($reply eq "y"));

print "Pulling caches...\n";
system "nix-pull `cat $tmpdir/caches`";
die if $?;

print "Installing package...\n";
system "nix-env -if $tmpdir/default.nix '*'";
die if $?;

print "Installation succeeded! Press Enter to continue.\n";
<STDIN>;