package Encode::JP::JIS7;
use strict;

our $VERSION = do { my @r = (q$Revision: 2.0 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };

use Encode qw(:fallbacks);

for my $name ('7bit-jis', 'iso-2022-jp', 'iso-2022-jp-1'){
    my $h2z     = ($name eq '7bit-jis')    ? 0 : 1;
    my $jis0212 = ($name eq 'iso-2022-jp') ? 0 : 1;

    $Encode::Encoding{$name} =
        bless {
               Name      =>   $name,
               h2z       =>   $h2z,
               jis0212   =>   $jis0212,
              } => __PACKAGE__;
}

use base qw(Encode::Encoding);

# we override this to 1 so PerlIO works
sub needs_lines { 1 }

use Encode::CJKConstants qw(:all);

#
# decode is identical for all 2022 variants
#

sub decode($$;$)
{
    my ($obj, $str, $chk) = @_;
    my $residue = '';
    if ($chk){
	$str =~ s/([^\x00-\x7f].*)$//so and $residue = $1;
    }
    $residue .= jis_euc(\$str);
    $_[1] = $residue if $chk;
    return Encode::decode('euc-jp', $str, FB_PERLQQ);
}

#
# encode is different
#

sub encode($$;$)
{
    require Encode::JP::H2Z;
    my ($obj, $utf8, $chk) = @_;
    # empty the input string in the stack so perlio is ok
    $_[1] = '' if $chk;
    my ($h2z, $jis0212) = @$obj{qw(h2z jis0212)};
    my $octet = Encode::encode('euc-jp', $utf8, FB_PERLQQ) ;
    $h2z and &Encode::JP::H2Z::h2z(\$octet);
    euc_jis(\$octet, $jis0212);
    return $octet;
}

#
# cat_decode
#
my $re_scan_jis_g = qr{
   \G ( ($RE{JIS_0212}) |  $RE{JIS_0208}  |
        ($RE{ISO_ASC})  | ($RE{JIS_KANA}) | )
      ([^\e]*)
}x;
sub cat_decode { # ($obj, $dst, $src, $pos, $trm, $chk)
    my ($obj, undef, undef, $pos, $trm) = @_; # currently ignores $chk
    my ($rdst, $rsrc, $rpos) = \@_[1,2,3];
    local ${^ENCODING};
    use bytes;
    my $opos = pos($$rsrc);
    pos($$rsrc) = $pos;
    while ($$rsrc =~ /$re_scan_jis_g/gc) {
	my ($esc, $esc_0212, $esc_asc, $esc_kana, $chunk) =
	  ($1, $2, $3, $4, $5);

	unless ($chunk) { $esc or last;  next; }

	if ($esc && !$esc_asc) {
	    $chunk =~ tr/\x21-\x7e/\xa1-\xfe/;
	    if ($esc_kana) {
		$chunk =~ s/([\xa1-\xdf])/\x8e$1/og;
	    } elsif ($esc_0212) {
		$chunk =~ s/([\xa1-\xfe][\xa1-\xfe])/\x8f$1/og;
	    }
	    $chunk = Encode::decode('euc-jp', $chunk, 0);
	}
	elsif ((my $npos = index($chunk, $trm)) >= 0) {
	    $$rdst .= substr($chunk, 0, $npos + length($trm));
	    $$rpos += length($esc) + $npos + length($trm);
	    pos($$rsrc) = $opos;
	    return 1;
	}
	$$rdst .= $chunk;
	$$rpos = pos($$rsrc);
    }
    $$rpos = pos($$rsrc);
    pos($$rsrc) = $opos;
    return '';
}

# JIS<->EUC
my $re_scan_jis = qr{
   (?:($RE{JIS_0212})|$RE{JIS_0208}|($RE{ISO_ASC})|($RE{JIS_KANA}))([^\e]*)
}x;

sub jis_euc {
    local ${^ENCODING};
    my $r_str = shift;
    $$r_str =~ s($re_scan_jis)
    {
	my ($esc_0212, $esc_asc, $esc_kana, $chunk) =
	   ($1, $2, $3, $4);
	if (!$esc_asc) {
	    $chunk =~ tr/\x21-\x7e/\xa1-\xfe/;
	    if ($esc_kana) {
		$chunk =~ s/([\xa1-\xdf])/\x8e$1/og;
	    }
	    elsif ($esc_0212) {
		$chunk =~ s/([\xa1-\xfe][\xa1-\xfe])/\x8f$1/og;
	    }
	}
	$chunk;
    }geox;
    my ($residue) = ($$r_str =~ s/(\e.*)$//so);
    return $residue;
}

sub euc_jis{
    no warnings qw(uninitialized);
    my $r_str = shift;
    my $jis0212 = shift;
    $$r_str =~ s{
	((?:$RE{EUC_C})+|(?:$RE{EUC_KANA})+|(?:$RE{EUC_0212})+)
	}{
	    my $chunk = $1;
	    my $esc =
		( $chunk =~ tr/\x8E//d ) ? $ESC{KANA} :
		    ( $chunk =~ tr/\x8F//d ) ? $ESC{JIS_0212} :
			$ESC{JIS_0208};
	    if ($esc eq $ESC{JIS_0212} && !$jis0212){
		# fallback to '?'
		$chunk =~ tr/\xA1-\xFE/\x3F/;
	    }else{
		$chunk =~ tr/\xA1-\xFE/\x21-\x7E/;
	    }
	    $esc . $chunk . $ESC{ASC};
	}geox;
    $$r_str =~
	s/\Q$ESC{ASC}\E
	    (\Q$ESC{KANA}\E|\Q$ESC{JIS_0212}\E|\Q$ESC{JIS_0208}\E)/$1/gox;
    $$r_str;
}

1;
__END__


=head1 NAME

Encode::JP::JIS7 -- internally used by Encode::JP

=cut
