#! @perl@ -w -I@libexecdir@/nix

use strict;
use File::Temp qw(tempdir);
use readmanifest;

my $tmpDir = tempdir("nix-pull.XXXXXX", CLEANUP => 1, TMPDIR => 1)
    or die "cannot create a temporary directory";

my $manifest = "$tmpDir/manifest";

my $binDir = $ENV{"NIX_BIN_DIR"};
$binDir = "@bindir@" unless defined $binDir;

my $libexecDir = $ENV{"NIX_LIBEXEC_DIR"};
$libexecDir = "@libexecdir@" unless defined $libexecDir;

my $stateDir = $ENV{"NIX_STATE_DIR"};
$stateDir = "@localstatedir@/nix" unless defined $stateDir;

my $storeDir = $ENV{"NIX_STORE_DIR"};
$storeDir = "@storedir@" unless defined $storeDir;


# Prevent access problems in shared-stored installations.
umask 0022;


# Process the URLs specified on the command line.
my %narFiles;
my %localPaths;
my %patches;

my $skipWrongStore = 0;

sub processURL {
    my $url = shift;

    $url =~ s/\/$//;
    print "obtaining list of Nix archives at $url...\n";

    system("@curl@ --fail --silent --show-error --location --max-redirs 20 " .
           "'$url' > '$manifest'") == 0
           or die "curl failed: $?";

    if (readManifest($manifest, \%narFiles, \%localPaths, \%patches) < 3) {
        die "manifest `$url' is too old (i.e., for Nix <= 0.7)\n";
    }

    if ($skipWrongStore) {
        foreach my $path (keys %narFiles) {
            if (substr($path, 0, length($storeDir) + 1) ne "$storeDir/") {
                print STDERR "warning: manifest `$url' assumes a Nix store at a different location than $storeDir, skipping...\n";
                exit 0;
            }
        }
    }

    my $baseName = "unnamed";
    if ($url =~ /\/([^\/]+)\/[^\/]+$/) { # get the forelast component
        $baseName = $1;
    }

    my $hash = `$binDir/nix-hash --flat '$manifest'`
        or die "cannot hash `$manifest'";
    chomp $hash;
    
    my $finalPath = "$stateDir/manifests/$baseName-$hash.nixmanifest";
    
    system ("@coreutils@/mv", "-f", "$manifest", "$finalPath") == 0
        or die "cannot move `$manifest' to `$finalPath";
}

while (@ARGV) {
    my $url = shift @ARGV;
    if ($url eq "--skip-wrong-store") {
        $skipWrongStore = 1;
    } else {
        processURL $url;
    }
}


my $size = scalar (keys %narFiles) + scalar (keys %localPaths);
print "$size store paths in manifest\n";


# Register all substitutes.
print STDERR "registering substitutes...\n";

my $pid = open(WRITE, "|$binDir/nix-store --register-substitutes")
    or die "cannot run nix-store";

sub writeRegistration {
    my $storePath = shift;
    my $object = shift;
    print WRITE "$storePath\n";
    print WRITE "$object->{deriver}\n";
    print WRITE "$libexecDir/nix/download-using-manifests.pl\n";
    print WRITE "0\n";
    my @references = split " ", $object->{references};
    my $count = scalar @references;
    print WRITE "$count\n";
    foreach my $reference (@references) {
        print WRITE "$reference\n";
    }
}

foreach my $storePath (keys %narFiles) {
    my $narFileList = $narFiles{$storePath};
    foreach my $narFile (@{$narFileList}) {
        writeRegistration $storePath, $narFile;
    }
}

foreach my $storePath (keys %localPaths) {
    my $localPathList = $localPaths{$storePath};
    foreach my $localPath (@{$localPathList}) {
        writeRegistration $storePath, $localPath;
    }
}

close WRITE or die "nix-store failed: $?";