use strict;


sub addPatch {
    my ($patches, $storePath, $patch) = @_;

    $$patches{$storePath} = []
        unless defined $$patches{$storePath};

    my $patchList = $$patches{$storePath};

    my $found = 0;
    foreach my $patch2 (@{$patchList}) {
        $found = 1 if
            $patch2->{url} eq $patch->{url} &&
            $patch2->{basePath} eq $patch->{basePath};
    }
    
    push @{$patchList}, $patch if !$found;

    return !$found;
}


sub readManifest {
    my ($manifest, $narFiles, $localPaths, $patches) = @_;

    open MANIFEST, "<$manifest"
        or die "cannot open `$manifest': $!";

    my $inside = 0;
    my $type;

    my $manifestVersion = 2;

    my $storePath;
    my $url;
    my $hash;
    my $size;
    my $basePath;
    my $baseHash;
    my $patchType;
    my $narHash;
    my $references;
    my $deriver;
    my $hashAlgo;
    my $copyFrom;

    while (<MANIFEST>) {
        chomp;
        s/\#.*$//g;
        next if (/^$/);

        if (!$inside) {

            if (/^\s*(\w*)\s*\{$/) {
                $type = $1;
                $type = "narfile" if $type eq "";
                $inside = 1;
                undef $storePath;
                undef $url;
                undef $hash;
                undef $size;
                undef $narHash;
                undef $basePath;
                undef $baseHash;
                undef $patchType;
                $references = "";
                $deriver = "";
                $hashAlgo = "md5";
	    }

        } else {
            
            if (/^\}$/) {
                $inside = 0;

                if ($type eq "narfile") {

                    $$narFiles{$storePath} = []
                        unless defined $$narFiles{$storePath};

                    my $narFileList = $$narFiles{$storePath};

                    my $found = 0;
                    foreach my $narFile (@{$narFileList}) {
                        $found = 1 if $narFile->{url} eq $url;
                    }
                    if (!$found) {
                        push @{$narFileList},
                            { url => $url, hash => $hash, size => $size
                            , narHash => $narHash, references => $references
                            , deriver => $deriver, hashAlgo => $hashAlgo
                            };
                    }
                
                }

                elsif ($type eq "patch") {
                    addPatch $patches, $storePath,
                        { url => $url, hash => $hash, size => $size
                        , basePath => $basePath, baseHash => $baseHash
                        , narHash => $narHash, patchType => $patchType
                        , hashAlgo => $hashAlgo
                        };
                }

                elsif ($type eq "localPath") {

                    $$localPaths{$storePath} = []
                        unless defined $$localPaths{$storePath};

                    my $localPathsList = $$localPaths{$storePath};

                    # !!! remove duplicates
                    
                    push @{$localPathsList},
                        { copyFrom => $copyFrom, references => $references
                        , deriver => ""
                        };
                }

            }
            
            elsif (/^\s*StorePath:\s*(\/\S+)\s*$/) { $storePath = $1; }
            elsif (/^\s*CopyFrom:\s*(\/\S+)\s*$/) { $copyFrom = $1; }
            elsif (/^\s*Hash:\s*(\S+)\s*$/) { $hash = $1; }
            elsif (/^\s*URL:\s*(\S+)\s*$/) { $url = $1; }
            elsif (/^\s*Size:\s*(\d+)\s*$/) { $size = $1; }
            elsif (/^\s*SuccOf:\s*(\/\S+)\s*$/) { } # obsolete
            elsif (/^\s*BasePath:\s*(\/\S+)\s*$/) { $basePath = $1; }
            elsif (/^\s*BaseHash:\s*(\S+)\s*$/) { $baseHash = $1; }
            elsif (/^\s*Type:\s*(\S+)\s*$/) { $patchType = $1; }
            elsif (/^\s*NarHash:\s*(\S+)\s*$/) { $narHash = $1; }
            elsif (/^\s*References:\s*(.*)\s*$/) { $references = $1; }
            elsif (/^\s*Deriver:\s*(\S+)\s*$/) { $deriver = $1; }
            elsif (/^\s*ManifestVersion:\s*(\d+)\s*$/) { $manifestVersion = $1; }

            # Compatibility;
            elsif (/^\s*NarURL:\s*(\S+)\s*$/) { $url = $1; }
            elsif (/^\s*MD5:\s*(\S+)\s*$/) { $hash = "md5:$1"; }

        }
    }

    close MANIFEST;

    return $manifestVersion;
}


sub writeManifest {
    my ($manifest, $narFiles, $patches) = @_;

    open MANIFEST, ">$manifest.tmp"; # !!! check exclusive

    print MANIFEST "version {\n";
    print MANIFEST "  ManifestVersion: 3\n";
    print MANIFEST "}\n";

    foreach my $storePath (sort (keys %{$narFiles})) {
        my $narFileList = $$narFiles{$storePath};
        foreach my $narFile (@{$narFileList}) {
            print MANIFEST "{\n";
            print MANIFEST "  StorePath: $storePath\n";
            print MANIFEST "  NarURL: $narFile->{url}\n";
            print MANIFEST "  Hash: $narFile->{hash}\n" if defined $narFile->{hash};
            print MANIFEST "  NarHash: $narFile->{narHash}\n";
            print MANIFEST "  Size: $narFile->{size}\n" if defined $narFile->{size};
            print MANIFEST "  References: $narFile->{references}\n"
                if defined $narFile->{references} && $narFile->{references} ne "";
            print MANIFEST "  Deriver: $narFile->{deriver}\n"
                if defined $narFile->{deriver} && $narFile->{deriver} ne "";
            print MANIFEST "}\n";
        }
    }
    
    foreach my $storePath (sort (keys %{$patches})) {
        my $patchList = $$patches{$storePath};
        foreach my $patch (@{$patchList}) {
            print MANIFEST "patch {\n";
            print MANIFEST "  StorePath: $storePath\n";
            print MANIFEST "  NarURL: $patch->{url}\n";
            print MANIFEST "  Hash: $patch->{hash}\n";
            print MANIFEST "  NarHash: $patch->{narHash}\n";
            print MANIFEST "  Size: $patch->{size}\n";
            print MANIFEST "  BasePath: $patch->{basePath}\n";
            print MANIFEST "  BaseHash: $patch->{baseHash}\n";
            print MANIFEST "  Type: $patch->{patchType}\n";
            print MANIFEST "}\n";
        }
    }
    
    
    close MANIFEST;

    rename("$manifest.tmp", $manifest)
        or die "cannot rename $manifest.tmp: $!";


    # Create a bzipped manifest.
    system("@bzip2@ < $manifest > $manifest.bz2.tmp") == 0
        or die "cannot compress manifest";

    rename("$manifest.bz2.tmp", "$manifest.bz2")
        or die "cannot rename $manifest.bz2.tmp: $!";
}


return 1;