package Graph::AdjacencyMap::Heavy;

# THIS IS INTERNAL IMPLEMENTATION ONLY, NOT TO BE USED DIRECTLY.
# THE INTERFACE IS HARD TO USE AND GOING TO STAY THAT WAY AND
# ALMOST GUARANTEED TO CHANGE OR GO AWAY IN FUTURE RELEASES.

use strict;

# $SIG{__DIE__ } = sub { use Carp; confess };
# $SIG{__WARN__} = sub { use Carp; confess };

use Graph::AdjacencyMap qw(:flags :fields);
use base 'Graph::AdjacencyMap';

require overload; # for de-overloading

require Data::Dumper;

sub __set_path {
    my $m = shift;
    my $f = $m->[ _f ];
    my $id = pop if ($f & _MULTI);
    if (@_ != $m->[ _a ] && !($f & _HYPER)) {
	require Carp;
	Carp::confess(sprintf "Graph::AdjacencyMap::Heavy: arguments %d expected %d",
		      scalar @_, $m->[ _a ]);
    }
    my $p;
    $p = ($f & _HYPER) ?
	(( $m->[ _s ] ||= [ ] )->[ @_ ] ||= { }) :
	(  $m->[ _s ]                   ||= { });
    my @p = $p;
    my @k;
    while (@_) {
	my $k = shift;
	my $q = ref $k && ($f & _REF) && overload::Method($k, '""') ? overload::StrVal($k) : $k;
	if (@_) {
	    $p = $p->{ $q } ||= {};
	    return unless $p;
	    push @p, $p;
	}
	push @k, $q;
    }
    return (\@p, \@k);
}

sub __set_path_node {
    my ($m, $p, $l) = splice @_, 0, 3;
    my $f = $m->[ _f ] ;
    my $id = pop if ($f & _MULTI);
    unless (exists $p->[-1]->{ $l }) {
	my $i = $m->_new_node( \$p->[-1]->{ $l }, $id );
	$m->[ _i ]->{ defined $i ? $i : "" } = [ @_ ];
        return defined $id ? ($id eq _GEN_ID ? $$id : $id) : $i;
    } else {
	return $m->_inc_node( \$p->[-1]->{ $l }, $id );
    }
}

sub set_path {
    my $m = shift;
    my $f = $m->[ _f ];
    if (@_ > 1 && ($f & _UNORDUNIQ)) {
	if (($f & _UNORDUNIQ) == _UNORD && @_ == 2) { @_ = sort @_ }
        else { $m->__arg(\@_) }
    }
    my ($p, $k) = $m->__set_path( @_ );
    return unless defined $p && defined $k;
    my $l = defined $k->[-1] ? $k->[-1] : "";
    return $m->__set_path_node( $p, $l, @_ );
}

sub __has_path {
    my $m = shift;
    my $f = $m->[ _f ];
    if (@_ != $m->[ _a ] && !($f & _HYPER)) {
	require Carp;
	Carp::confess(sprintf "Graph::AdjacencyMap::Heavy: arguments %d expected %d",
		      scalar @_, $m->[ _a ]);
    }
    if (@_ > 1 && ($f & _UNORDUNIQ)) {
	if (($f & _UNORDUNIQ) == _UNORD && @_ == 2) { @_ = sort @_ }
        else { $m->__arg(\@_) }
    }
    my $p = $m->[ _s ];
    return unless defined $p;
    $p = $p->[ @_ ] if ($f & _HYPER);
    return unless defined $p;
    my @p = $p;
    my @k;
    while (@_) {
	my $k = shift;
	my $q = ref $k && ($f & _REF) && overload::Method($k, '""') ? overload::StrVal($k) : $k;
	if (@_) {
	    $p = $p->{ $q };
	    return unless defined $p;
	    push @p, $p;
	}
	push @k, $q;
    }
    return (\@p, \@k);
}

sub has_path {
    my $m = shift;
    my $f = $m->[ _f ];
    if (@_ > 1 && ($f & _UNORDUNIQ)) {
	if (($f & _UNORDUNIQ) == _UNORD && @_ == 2) { @_ = sort @_ }
        else { $m->__arg(\@_) }
    }
    my ($p, $k) = $m->__has_path( @_ );
    return unless defined $p && defined $k;
    return exists $p->[-1]->{ defined $k->[-1] ? $k->[-1] : "" };
}

sub has_path_by_multi_id {
    my $m = shift;
    my $f = $m->[ _f ];
    my $id = pop;
    if (@_ > 1 && ($f & _UNORDUNIQ)) {
	if (($f & _UNORDUNIQ) == _UNORD && @_ == 2) { @_ = sort @_ }
        else { $m->__arg(\@_) }
    }
    my ($e, $n) = $m->__get_path_node( @_ );
    return undef unless $e;
    return exists $n->[ _nm ]->{ $id };
}

sub _get_path_node {
    my $m = shift;
    my $f = $m->[ _f ];
    if ($m->[ _a ] == 2 && @_ == 2 && !($f & (_HYPER|_REF|_UNIQ))) { # Fast path.
	@_ = sort @_ if ($f & _UNORD);
	return unless exists $m->[ _s ]->{ $_[0] };
	my $p = [ $m->[ _s ], $m->[ _s ]->{ $_[0] } ];
	my $k = [ $_[0], $_[1] ];
	my $l = $_[1];
	return ( exists $p->[-1]->{ $l }, $p->[-1]->{ $l }, $p, $k, $l );
    } else {
	if (@_ > 1 && ($f & _UNORDUNIQ)) {
	    if (($f & _UNORDUNIQ) == _UNORD && @_ == 2) { @_ = sort @_ }
	    else { $m->__arg(\@_) }
	}
	$m->__get_path_node( @_ );
    }
}

sub _get_path_id {
    my $m = shift;
    my $f = $m->[ _f ];
    my ($e, $n);
    if ($m->[ _a ] == 2 && @_ == 2 && !($f & (_HYPER|_REF|_UNIQ))) { # Fast path.
	@_ = sort @_ if ($f & _UNORD);
	return unless exists $m->[ _s ]->{ $_[0] };
	my $p = $m->[ _s ]->{ $_[0] };
	$e = exists $p->{ $_[1] };
	$n = $p->{ $_[1] };
    } else {
	($e, $n) = $m->_get_path_node( @_ );
    }
    return undef unless $e;
    return ref $n ? $n->[ _ni ] : $n;
}

sub _get_path_count {
    my $m = shift;
    my $f = $m->[ _f ];
    my ($e, $n) = $m->_get_path_node( @_ );
    return undef unless $e && defined $n;
    return
	($f & _COUNT) ? $n->[ _nc ] :
	($f & _MULTI) ? scalar keys %{ $n->[ _nm ] } : 1;
}

sub __attr {
    my $m = shift;
    if (@_) {
	if (ref $_[0] && @{ $_[0] }) {
	    if (@{ $_[0] } != $m->[ _a ]) {
		require Carp;
		Carp::confess(sprintf
			      "Graph::AdjacencyMap::Heavy: arguments %d expected %d\n",
			      scalar @{ $_[0] }, $m->[ _a ]);
	    }
	    my $f = $m->[ _f ];
	    if (@{ $_[0] } > 1 && ($f & _UNORDUNIQ)) {
		if (($f & _UNORDUNIQ) == _UNORD && @{ $_[0] } == 2) {
		    @{ $_[0] } = sort @{ $_[0] }
		} else { $m->__arg(\@_) }
	    }
	}
    }
}

sub _get_id_path {
    my ($m, $i) = @_;
    my $p = defined $i ? $m->[ _i ]->{ $i } : undef;
    return defined $p ? @$p : ( );
}

sub del_path {
    my $m = shift;
    my $f = $m->[ _f ];
    if (@_ > 1 && ($f & _UNORDUNIQ)) {
	if (($f & _UNORDUNIQ) == _UNORD && @_ == 2) { @_ = sort @_ }
        else { $m->__arg(\@_) }
    }
    my ($e, $n, $p, $k, $l) = $m->__get_path_node( @_ );
    return unless $e;
    my $c = ($f & _COUNT) ? --$n->[ _nc ] : 0;
    if ($c == 0) {
	delete $m->[ _i ]->{ ref $n ? $n->[ _ni ] : $n };
	delete $p->[-1]->{ $l };
	while (@$p && @$k && keys %{ $p->[-1]->{ $k->[-1] } } == 0) {
	    delete $p->[-1]->{ $k->[-1] };
	    pop @$p;
	    pop @$k;
	}
    }
    return 1;
}

sub del_path_by_multi_id {
    my $m = shift;
    my $f = $m->[ _f ];
    my $id = pop;
    if (@_ > 1 && ($f & _UNORDUNIQ)) {
	if (($f & _UNORDUNIQ) == _UNORD && @_ == 2) { @_ = sort @_ }
        else { $m->__arg(\@_) }
    }
    my ($e, $n, $p, $k, $l) = $m->__get_path_node( @_ );
    return unless $e;
    delete $n->[ _nm ]->{ $id };
    unless (keys %{ $n->[ _nm ] }) {
	delete $m->[ _i ]->{ $n->[ _ni ] };
	delete $p->[-1]->{ $l };
	while (@$p && @$k && keys %{ $p->[-1]->{ $k->[-1] } } == 0) {
	    delete $p->[-1]->{ $k->[-1] };
	    pop @$p;
	    pop @$k;
	}
    }
    return 1;
}

sub paths {
    my $m = shift;
    return values %{ $m->[ _i ] } if defined $m->[ _i ];
    wantarray ? ( ) : 0;
}

1;
__END__