package PHP::Serialization;
use strict;
use warnings;
use Exporter ();
use Scalar::Util qw/blessed/;
use Carp qw(croak confess carp);
use bytes;

use vars qw/$VERSION @ISA @EXPORT_OK/;

$VERSION = '0.32';
	
@ISA = qw(Exporter);	
@EXPORT_OK = qw(unserialize serialize);

=head1 NAME

PHP::Serialization - simple flexible means of converting the output of PHP's serialize() into the equivalent Perl memory structure, and vice versa.

=head1 SYNOPSIS

	use PHP::Serialization qw(serialize unserialize);
	my $encoded = serialize({ a => 1, b => 2});
	my $hashref = unserialize($encoded);

=cut


=head1 DESCRIPTION

Provides a simple, quick means of serializing perl memory structures (including object data!) into a format that PHP can deserialize() and access, and vice versa. 

NOTE: Converts PHP arrays into Perl Arrays when the PHP array used exclusively numeric indexes, and into Perl Hashes then the PHP array did not.

=cut

sub new {
    my ($class) = shift;
	my $self = bless {}, blessed($class) ? blessed($class) : $class;
	return $self;
}

=head1 FUNCTIONS

Exportable functions..

=cut

=head2 serialize($var)

Serializes the memory structure pointed to by $var, and returns a scalar value of encoded data. 

NOTE: Will recursively encode objects, hashes, arrays, etc. 

SEE ALSO: ->encode()

=cut

sub serialize {
	return __PACKAGE__->new->encode(@_);
}

=head2 unserialize($encoded,[optional CLASS])

Deserializes the encoded data in $encoded, and returns a value (be it a hashref, arrayref, scalar, etc) 
representing the data structure serialized in $encoded_string.

If the optional CLASS is specified, any objects are blessed into CLASS::$serialized_class. Otherwise, O
bjects are blessed into PHP::Serialization::Object::$serialized_class. (which has no methods)

SEE ALSO: ->decode()

=cut

sub unserialize {
	return __PACKAGE__->new->decode(@_);
}

=head1 METHODS

Functionality available if using the object interface..

=cut

=head2 decode($encoded_string,[optional CLASS])

Deserializes the encoded data in $encoded, and returns a value (be it a hashref, arrayref, scalar, etc) 
representing the data structure serialized in $encoded_string.

If the optional CLASS is specified, any objects are blessed into CLASS::$serialized_class. Otherwise, 
Objects are blessed into PHP::Serialization::Object::$serialized_class. (which has no methods)

SEE ALSO: unserialize()

=cut

sub decode {
	my ($self, $string, $class) = @_;

	my $cursor = 0;
	$self->{string} = \$string;
	$self->{cursor} = \$cursor;
	$self->{strlen} = length($string);

	if ( defined $class ) {
		$self->{class} = $class;
	} 
	else {
		$self->{class} = 'PHP::Serialization::Object';
	}	

	# Ok, start parsing...
	my @values = $self->_parse();

	# Ok, we SHOULD only have one value.. 
	if ( $#values == -1 ) {
		# Oops, none...
		return;
	} 
	elsif ( $#values == 0 ) {
		# Ok, return our one value..
		return $values[0];
	} 
	else {
		# Ok, return a reference to the list.
		return \@values;
	}

} # End of decode sub.

my %type_table = (
	O => 'object',
	s => 'scalar',
	a => 'array',
	i => 'integer',
	d => 'float',
	b => 'boolean',
	N => 'undef',
);

sub _parse_array {
	my $self = shift;
	my $elemcount = shift;
	my $cursor = $self->{cursor};
	my $string = $self->{string};
	my $strlen = $self->{strlen};
	confess("No cursor") unless $cursor;
	confess("No string") unless $string;
	confess("No strlen") unless $strlen;
	
	my @elems = ();

	$self->_skipchar('{');
	foreach my $i (1..$elemcount*2) {
		push(@elems,$self->_parse_elem);
	}
	$self->_skipchar('}');
	return @elems;
}

sub _parse_elem {
	my $self = shift;
	my $cursor = $self->{cursor};
	my $string = $self->{string};
	my $strlen = $self->{strlen};
	
	my @elems;
	
	my $type_c = $self->_readchar();
	my $type = $type_table{$type_c};
	if (!defined $type) {
		croak("ERROR: Unknown type $type_c.");
	}
	
	if ( $type eq 'object' ) {
		$self->_skipchar(':');
		# Ok, get our name count...
		my $namelen = $self->_readnum();
		$self->_skipchar(':');

		# Ok, get our object name...
		$self->_skipchar('"');
		my $name = $self->_readstr($namelen);
		$self->_skipchar('"');

		# Ok, our sub elements...
		$self->_skipchar(':');
		my $elemcount = $self->_readnum();
		$self->_skipchar(':');

		my %value = $self->_parse_array($elemcount);
		
		# TODO: Call wakeup
		# TODO: Support for objecttypes
		return bless(\%value, $self->{class} . '::' . $name);
	} elsif ( $type eq 'array' ) {
		$self->_skipchar(':');
		# Ok, our sub elements...
		my $elemcount = $self->_readnum();
		$self->_skipchar(':');

		my @values = $self->_parse_array($elemcount);
		# If every other key is not numeric, map to a hash..
		my $subtype = 'array';
		my @newlist;
		foreach ( 0..$#values ) {
			if ( ($_ % 2) ) { 
				push(@newlist, $values[$_]);
				next; 
			} elsif (($_ / 2) ne $values[$_]) {
				$subtype = 'hash';
				last;
			}
			if ( $values[$_] !~ /^\d+$/ ) {
				$subtype = 'hash';
				last;
			}
		}
		if ( $subtype eq 'array' ) {
			# Ok, remap...
			return \@newlist;
		} else {
			# Ok, force into hash..
			my %hash = @values;
			return \%hash;
		}
	} 
	elsif ( $type eq 'scalar' ) {
		$self->_skipchar(':');
		# Ok, get our string size count...
		my $strlen = $self->_readnum;
		$self->_skipchar(':');

		$self->_skipchar('"');
		my $string = $self->_readstr($strlen);
		$self->_skipchar('"');
		$self->_skipchar(';');
		return $string;
	} 
	elsif ( $type eq 'integer' || $type eq 'float' ) {
		$self->_skipchar(':');
		# Ok, read the value..
		my $val = $self->_readnum;
		if ( $type eq 'integer' ) { $val = int($val); }
		$self->_skipchar(';');
		return $val;
	} 
	elsif ( $type eq 'boolean' ) {
		$self->_skipchar(':');
		# Ok, read our boolen value..
		my $bool = $self->_readchar;

		$self->_skipchar;
        if ($bool eq '0') {
            $bool = undef;
        }
		return $bool;
	} 
	elsif ( $type eq 'undef' ) {
		$self->_skipchar(';');
		return undef;
	} 
	else {
		confess "Unknown element type '$type' found! (cursor $$cursor)";
	}
	
}


sub _parse {
	my ($self) = @_;
	my $cursor = $self->{cursor};
	my $string = $self->{string};
	my $strlen = $self->{strlen};
	confess("No cursor") unless $cursor;
	confess("No string") unless $string;
	confess("No strlen") unless $strlen;
	my @elems;
	push(@elems,$self->_parse_elem);
	
	# warn if we have unused chars
	if ($$cursor != $strlen) {
		carp("WARN: Unused characters in string after $$cursor.");
	}
	return @elems;
	
} # End of decode.

sub _readstr {
	my ($self, $length) = @_;
	my $string = $self->{string};
	my $cursor = $self->{cursor};
	if ($$cursor + $length > length($$string)) {
		croak("ERROR: Read past end of string. Want $length after $$cursor. (".$$string.")");
	}
	my $str = substr($$string, $$cursor, $length);
	$$cursor += $length;

	return $str;
}

sub _readchar {
	my ($self) = @_;
	return $self->_readstr(1);
}

sub _readnum {
	# Reads in a character at a time until we run out of numbers to read...
	my ($self) = @_;
	my $cursor = $self->{cursor};

	my $string;
	while ( 1 ) {
		my $char = $self->_readchar;
		if ( $char !~ /^[\d\.-]+$/ ) {
			$$cursor--;
			last;
		}
		$string .= $char;
	} # End of while.

	return $string;
} # End of readnum

sub _skipchar {
	my $self = shift;
	my $want = shift;
    my $c = $self->_readchar();
	if (($want)&&($c ne $want)) {
		my $cursor = $self->{cursor};
		my $str = $self->{string};
		croak("ERROR: Wrong char $c, expected $want at position ".$$cursor." (".$$str.")");
	}
	print "_skipchar: WRONG char $c ($want)\n" if (($want)&&($c ne $want));
	# ${$$self{cursor}}++;
} # Move our cursor one bytes ahead...


=head2 encode($reference)

Serializes the memory structure pointed to by $var, and returns a scalar value of encoded data. 

NOTE: Will recursively encode objects, hashes, arrays, etc. 

SEE ALSO: serialize()

=cut

sub encode {
	my ($self, $val, $iskey) = @_;
	$iskey=0 unless defined $iskey;

	if ( ! defined $val ) {
		return $self->_encode('null', $val);
	}
	elsif ( blessed $val ) {
	    return $self->_encode('obj', $val);
	}
	elsif ( ! ref($val) ) {
		if ( $val =~ /^-?\d{1,10}$/ && abs($val) < 2**31 ) {
			return $self->_encode('int', $val);
		} 
		elsif ( $val =~ /^-?\d+\.\d*$/ && !$iskey) {
			return $self->_encode('float', $val);
		} 
		else {
			return $self->_encode('string', $val);
		}
	} 
	else {
		my $type = ref($val);
		if ($type eq 'HASH' || $type eq 'ARRAY' ) {
			return $self->_encode('array', $val);
		} 
		else {
			confess "I can't serialize data of type '$type'!";
		}
	}
}

sub _encode {
	my ($self, $type, $val) = @_;

	my $buffer = '';
	if ( $type eq 'null' ) {
		$buffer .= 'N;';
	} 
	elsif ( $type eq 'int' ) {
		$buffer .= sprintf('i:%d;', $val);
	} 
	elsif ( $type eq 'float' ) {
		$buffer .= sprintf('d:%s;', $val);
	} 
	elsif ( $type eq 'string' ) {
		$buffer .= sprintf('s:%d:"%s";', length($val), $val);
	} 
	elsif ( $type eq 'array' ) {
		if ( ref($val) eq 'ARRAY' ) {
			$buffer .= sprintf('a:%d:',($#{$val}+1)) . '{';
			map { # Ewww
			    $buffer .= $self->encode($_); 
			    $buffer .= $self->encode($$val[$_]); 
			} 0..$#{$val};
			$buffer .= '}';
		} 
		else {
			$buffer .= sprintf('a:%d:',scalar(keys(%{$val}))) . '{';
 			while ( my ($key, $value) = each(%{$val}) ) {
 			    $buffer .= $self->encode($key,1);
 			    $buffer .= $self->encode($value);
			}
			$buffer .= '}';	
		}
	} 
	elsif ( $type eq 'obj' ) {
		my $class = ref($val);
		$class =~ /(\w+)$/;
		my $subclass = $1;
		$buffer .= sprintf('O:%d:"%s":%d:', length($subclass), $subclass, scalar(keys %{$val})) . '{';
		foreach ( %{$val} ) { 
		    $buffer .= $self->encode($_); 
		}
		$buffer .= '}';
	} 
	else {
		confess "Unknown encode type!";
	}	
	return $buffer;	

}

=head1 TODO

Support diffrent object types

=head1 AUTHOR INFORMATION

Copyright (c) 2003 Jesse Brown <jbrown@cpan.org>. All rights reserved. This program is free software; 
you can redistribute it and/or modify it under the same terms as Perl itself.

Various patches contributed by assorted authors on rt.cpan.org (as detailed in Changes file).

Currently maintained by Tomas Doran <bobtfish@bobtfish.net>.

Rewritten to solve all known bugs by Bjørn-Olav Strand <bolav@cpan.org>

=cut

package PHP::Serialization::Object;

1;
