package partition_table_sun;

use diagnostics;
use strict;
use vars qw(@ISA);

@ISA = qw(partition_table_raw);

use common qw(:common :system :file :functional);
use partition_table_raw;
use partition_table;
use c;

#- very bad and rough handling :(
my %typeToDos = (
  5 => 0,
);
my %typeFromDos = reverse %typeToDos;

my ($main_format, $main_fields) = list2kv(
  a128  => 'info',
  a14   => 'spare0',
  a32   => 'infos',
  a246  => 'spare1',
  n     => 'rspeed',
  n     => 'pcylcount',
  n     => 'sparecyl',
  a4    => 'spare2',
  n     => 'ilfact',
  n     => 'ncyl',
  n     => 'nacyl',
  n     => 'ntrks',
  n     => 'nsect',
  a4    => 'spare3',
  a64   => 'partitions',
  n     => 'magic',
  n     => 'csum',
);
$main_format = join '', @$main_format;

my ($fields1, $fields2) = ([ qw(type flags) ], [ qw(start_cylinder size) ]);
my ($format1, $format2) = ("x C x C", "N N");
my ($size1, $size2) = map { psizeof($_) } ($format1, $format2);
my $magic = 0xDABE;
my $nb_primary = 8;
my $offset = 0;

sub read($$) {
    my ($hd, $sector) = @_;
    my $tmp;

    local *F; partition_table_raw::openit($hd, *F) or die "failed to open device";
    c::lseek_sector(fileno(F), $sector, $offset) or die "reading of partition in sector $sector failed";

    sysread F, $tmp, psizeof($main_format) or die "error while reading partition table in sector $sector";
    my %info; @info{@$main_fields} = unpack $main_format, $tmp;

    #- check magic number
    $info{magic}  == $magic or die "bad magic number";

    @{$hd->{geom}}{qw(cylinders heads sectors)} = @info{qw(ncyl nsect ntrks)};

    #- TODO verify checksum
    my @pt = mapn {
	my %h; 
	@h{@$fields1} = unpack $format1, $_[0];
	@h{@$fields2} = unpack $format2, $_[1];
	$h{start} = $sector + $h{start_cylinder} * partition_table::cylinder_size($hd);
	$h{type} = $typeToDos{$h{type}} || $h{type};
	$h{size} or $h{$_} = 0 foreach keys %h;
	\%h;
    } [ $info{infos} =~ /(.{$size1})/g ], [ $info{partitions} =~ /(.{$size2})/g ];

    [ @pt ], \%info;
}

# write the partition table (and extended ones)
# for each entry, it uses fields: start, size, type, active
sub write($$$;$) {
    my ($hd, $sector, $pt, $info) = @_;

    local *F; partition_table_raw::openit($hd, *F, 2) or die "error opening device $hd->{device} for writing";
    c::lseek_sector(fileno(F), $sector, $offset) or return 0;

    #- TODO compute checksum

    ($info->{infos}, $info->{partitions}) = map { join '', @$_ } list2kv map {
	$_->{start} % partition_table::cylinder_size($hd) == 0 or die "partition not at beginning of cylinder";
	local $_->{type} = $typeFromDos{$_->{type}} || $_->{type};
	local $_->{start_cylinder} = $_->{start} / partition_table::cylinder_size($hd) - $sector;
	pack($format1, @$_{@$fields1}), pack($format2, @$_{@$fields2});
    } @$pt;

    syswrite F, pack($main_format, @$info{@$main_fields}), psizeof($main_format) or return 0;

    1;
}

sub info {
    my ($hd) = @_;
    my $dtype_scsi  = 4; #- taken from fdisk, removed unused one,
    my $dtype_ST506 = 6; #- see fdisk for more

    {
      magic => $magic,
      magic2 => $magic,
      dtype => $hd->{device} =~ /^sd/ ? $dtype_scsi : $dtype_ST506,
      secsize => $common::SECTORSIZE,
      ncylinders => $hd->{geom}{cylinders},
      secpercyl => partition_table::cylinder_size($hd),
      secprtunit => $hd->{geom}{totalsectors},
      rpm => 3600,
      interleave => 1,
      trackskew => 0,
      cylskew => 0,
      headswitch => 0,
      trkseek => 0,
      bbsize => 8192, #- size of boot area, with label
      sbsize => 8192, #- max size of fs superblock
    };
}

sub clear_raw {
    my ($hd) = @_;
    { raw => [ ({}) x $nb_primary ], info => info($hd) };
}

1;