package IO::Uncompress::Inflate ;
# for RFC1950

use strict ;
use warnings;
use bytes;

use IO::Compress::Base::Common  2.015 qw(:Status createSelfTiedObject);
use IO::Compress::Zlib::Constants 2.015 ;

use IO::Uncompress::RawInflate  2.015 ;

require Exporter ;
our ($VERSION, @ISA, @EXPORT_OK, %EXPORT_TAGS, $InflateError);

$VERSION = '2.015';
$InflateError = '';

@ISA    = qw( Exporter IO::Uncompress::RawInflate );
@EXPORT_OK = qw( $InflateError inflate ) ;
%EXPORT_TAGS = %IO::Uncompress::RawInflate::DEFLATE_CONSTANTS ;
push @{ $EXPORT_TAGS{all} }, @EXPORT_OK ;
Exporter::export_ok_tags('all');


sub new
{
    my $class = shift ;
    my $obj = createSelfTiedObject($class, \$InflateError);

    $obj->_create(undef, 0, @_);
}

sub inflate
{
    my $obj = createSelfTiedObject(undef, \$InflateError);
    return $obj->_inf(@_);
}

sub getExtraParams
{
    return ();
}

sub ckParams
{
    my $self = shift ;
    my $got = shift ;

    # gunzip always needs adler32
    $got->value('ADLER32' => 1);

    return 1;
}

sub ckMagic
{
    my $self = shift;

    my $magic ;
    $self->smartReadExact(\$magic, ZLIB_HEADER_SIZE);

    *$self->{HeaderPending} = $magic ;

    return $self->HeaderError("Header size is " . 
                                        ZLIB_HEADER_SIZE . " bytes") 
        if length $magic != ZLIB_HEADER_SIZE;

    #return $self->HeaderError("CRC mismatch.")
    return undef
        if ! $self->isZlibMagic($magic) ;
                      
    *$self->{Type} = 'rfc1950';
    return $magic;
}

sub readHeader
{
    my $self = shift;
    my $magic = shift ;

    return $self->_readDeflateHeader($magic) ;
}

sub chkTrailer
{
    my $self = shift;
    my $trailer = shift;

    my $ADLER32 = unpack("N", $trailer) ;
    *$self->{Info}{ADLER32} = $ADLER32;    
    return $self->TrailerError("CRC mismatch")
        if *$self->{Strict} && $ADLER32 != *$self->{Uncomp}->adler32() ;

    return STATUS_OK;
}



sub isZlibMagic