# -*- Mode: cperl; coding: utf-8; cperl-indent-level: 4 -*-
# vim: ts=4 sts=4 sw=4:
package CPAN::Exception::RecursiveDependency;
use strict;
use overload '""' => "as_string";

use vars qw(
$VERSION
);
$VERSION = "5.5";

# a module sees its distribution (no version)
# a distribution sees its prereqs (which are module names) (usually with versions)
# a bundle sees its module names and/or its distributions (no version)

sub new {
my($class) = shift;
my($deps_arg) = shift;
my (@deps,%seen,$loop_starts_with);
DCHAIN: for my $dep (@$deps_arg) {
push @deps, {name => $dep, display_as => $dep};
if ($seen{$dep}++) {
$loop_starts_with = $dep;
last DCHAIN;
}
}
my $in_loop = 0;
for my $i (0..$#deps) {
my $x = $deps[$i]{name};
$in_loop ||= $loop_starts_with && $x eq $loop_starts_with;
my $xo = CPAN::Shell->expandany($x) or next;
if ($xo->isa("CPAN::Module")) {
my $have = $xo->inst_version || "N/A";
my($want,$d,$want_type);
if ($i>0 and $d = $deps[$i-1]{name}) {
my $do = CPAN::Shell->expandany($d);
$want = $do->{prereq_pm}{requires}{$x};
if (defined $want) {
$want_type = "requires: ";
} else {
$want = $do->{prereq_pm}{build_requires}{$x};
if (defined $want) {
$want_type = "build_requires: ";
} else {
$want_type = "unknown status";
$want = "???";
}
}
} else {
$want = $xo->cpan_version;
$want_type = "want: ";
}
$deps[$i]{have} = $have;
$deps[$i]{want_type} = $want_type;
$deps[$i]{want} = $want;
$deps[$i]{display_as} = "$x (have: $have; $want_type$want)";
} elsif ($xo->isa("CPAN::Distribution")) {
$deps[$i]{display_as} = $xo->pretty_id;
if ($in_loop) {
$xo->{make} = CPAN::Distrostatus->new("NO cannot resolve circular dependency");
} else {
$xo->{make} = CPAN::Distrostatus->new("NO one dependency ($loop_starts_with) is a circular dependency");
}
$xo->store_persistent_state; # otherwise I will not reach
# all involved parties for
# the next session
}
}
bless { deps => \@deps, loop_starts_with => $loop_starts_with }, $class;
}

sub as_string {
my($self) = shift;
my $deps = $self->{deps};
my $loop_starts_with = $self->{loop_starts_with};
unless ($loop_starts_with) {
return "--not a recursive/circular dependency--";
}
my $ret = "\nRecursive dependency detected:\n ";
$ret .= join("\n => ", map {$_->{display_as}} @$deps);
$ret .= ".\nCannot resolve.\n";
$ret;
}

1;