#! @perl@ -w @perlFlags@

use strict;
use File::Temp qw(tempdir);
use Nix::Manifest;
use Nix::GeneratePatches;

if (scalar @ARGV != 5) {
    print STDERR <<EOF;
Usage: nix-generate-patches NAR-DIR PATCH-DIR PATCH-URI OLD-MANIFEST NEW-MANIFEST

This command generates binary patches between NAR files listed in
OLD-MANIFEST and NEW-MANIFEST.  The patches are written to the
directory PATCH-DIR, and the prefix PATCH-URI is used to generate URIs
for the patches.  The patches are added to NEW-MANIFEST.  All NARs are
required to exist in NAR-DIR.  Patches are generated between
succeeding versions of packages with the same name.
EOF
    exit 1;
}

my $narPath = $ARGV[0];
my $patchesPath = $ARGV[1];
my $patchesURL = $ARGV[2];
my $srcManifest = $ARGV[3];
my $dstManifest = $ARGV[4];

my (%srcNarFiles, %srcLocalPaths, %srcPatches);
readManifest $srcManifest, \%srcNarFiles, \%srcPatches;

my (%dstNarFiles, %dstLocalPaths, %dstPatches);
readManifest $dstManifest, \%dstNarFiles, \%dstPatches;

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

generatePatches \%srcNarFiles, \%dstNarFiles, \%srcPatches, \%dstPatches,
    $narPath, $patchesPath, $patchesURL, $tmpDir;

propagatePatches \%srcPatches, \%dstNarFiles, \%dstPatches;

# Optionally add all new patches to the manifest in $NIX_ALL_PATCHES.
my $allPatchesFile = $ENV{"NIX_ALL_PATCHES"};
if (defined $allPatchesFile) {
    my (%dummy, %allPatches);
    readManifest("$patchesPath/all-patches", \%dummy, \%allPatches)
        if -f $allPatchesFile;
    copyPatches \%dstPatches, \%allPatches;
    writeManifest($allPatchesFile, {}, \%allPatches, 0);
}

writeManifest $dstManifest, \%dstNarFiles, \%dstPatches;