#! @perl@ -w @perlFlags@

use Nix::SSH;
use Nix::Config;
use Nix::Store;
use Nix::CopyClosure;
use List::Util qw(sum);


if (scalar @ARGV < 1) {
    print STDERR <<EOF
Usage: nix-copy-closure [--from | --to] HOSTNAME [--sign] [--gzip] [--bzip2] [--xz] PATHS...
EOF
    ;
    exit 1;
}


# Get the target host.
my $sshHost;
my $sign = 0;
my $compressor = "";
my $decompressor = "";
my $progressViewer = "";
my $toMode = 1;
my $includeOutputs = 0;
my $dryRun = 0;
my $useSubstitutes = 0;


# !!! Copied from nix-pack-closure, should put this in a module.
my @storePaths = ();

while (@ARGV) {
    my $arg = shift @ARGV;

    if ($arg eq "--help") {
        exec "man nix-copy-closure" or die;
    }
    elsif ($arg eq "--sign") {
        $sign = 1;
    }
    elsif ($arg eq "--gzip") {
        $compressor = "gzip";
        $decompressor = "gunzip";
    }
    elsif ($arg eq "--bzip2") {
        $compressor = "bzip2";
        $decompressor = "bunzip2";
    }
    elsif ($arg eq "--xz") {
        $compressor = "xz";
        $decompressor = "xz -d";
    }
    elsif ($arg eq "--from") {
        $toMode = 0;
    }
    elsif ($arg eq "--to") {
        $toMode = 1;
    }
    elsif ($arg eq "--include-outputs") {
        $includeOutputs = 1;
    }
    elsif ($arg eq "--show-progress") {
        $progressViewer = "pv";
    }
    elsif ($arg eq "--dry-run") {
        $dryRun = 1;
    }
    elsif ($arg eq "--use-substitutes" || $arg eq "-s") {
        $useSubstitutes = 1;
    }
    elsif (!defined $sshHost) {
        $sshHost = $arg;
    }
    else {
        push @storePaths, $arg;
    }
}


openSSHConnection $sshHost or die "$0: unable to start SSH\n";


if ($toMode) { # Copy TO the remote machine.
    Nix::CopyClosure::copyTo(
        $sshHost, [ @sshOpts ], [ @storePaths ], $compressor, $decompressor,
        $includeOutputs, $dryRun, $sign, $progressViewer, $useSubstitutes);
}

else { # Copy FROM the remote machine.

    # Query the closure of the given store paths on the remote
    # machine.  Paths are assumed to be store paths; there is no
    # resolution (following of symlinks).
    my $extraOpts = $includeOutputs ? "--include-outputs" : "";
    my $pid = open(READ,
        "set -f; ssh @sshOpts $sshHost nix-store --query --requisites $extraOpts @storePaths|") or die;

    while (<READ>) {
        chomp;
        die "bad: $_" unless /^\//;
        push @missing, $_ unless isValidPath($_);
    }

    close READ or die "nix-store on remote machine `$sshHost' failed: $?";

    my $missingSize = 0;
    if ($progressViewer ne "") {
        $missingSize = sum (split ' ', `set -f; ssh @sshOpts $sshHost nix-store -q --size @missing`) or die;
    }

    # Export the store paths on the remote machine and import them locally.
    if (scalar @missing > 0) {
        print STDERR "copying ", scalar @missing, " missing paths from ‘$sshHost’...\n";
        unless ($dryRun) {
            if ($useSubstitutes) {
                system "$Nix::Config::binDir/nix-store -r --ignore-unknown @missing";
            }
            $compressor = "| $compressor" if $compressor ne "";
            $decompressor = "$decompressor |" if $decompressor ne "";
            $progressViewer = "$progressViewer -s $missingSize |" if $progressViewer ne "";
            my $extraOpts = $sign ? "--sign" : "";
            system("set -f; ssh $sshHost @sshOpts 'nix-store --export $extraOpts @missing $compressor' | $progressViewer $decompressor $Nix::Config::binDir/nix-store --import > /dev/null") == 0
                or die "copying store paths from remote machine `$sshHost' failed: $?";
        }
    }

}