1 files changed, 117 insertions, 0 deletions
diff --git a/lib/Module/CPANfile/Prereqs.pm b/lib/Module/CPANfile/Prereqs.pm
new file mode 100644
index 0000000..c3126ea
--- /dev/null
+++ b/lib/Module/CPANfile/Prereqs.pm
@@ -0,0 +1,117 @@
+package Module::CPANfile::Prereqs;
+use strict;
+use Carp ();
+use CPAN::Meta::Feature;
+use Module::CPANfile::Prereq;
+
+sub from_cpan_meta {
+    my($class, $prereqs) = @_;
+
+    my $self = $class->new;
+
+    for my $phase (keys %$prereqs) {
+        for my $type (keys %{ $prereqs->{$phase} }) {
+            while (my($module, $requirement) = each %{ $prereqs->{$phase}{$type} }) {
+                $self->add_prereq(
+                    phase => $phase,
+                    type  => $type,
+                    module => $module,
+                    requirement => Module::CPANfile::Requirement->new(name => $module, version => $requirement),
+                );
+            }
+        }
+    }
+
+    $self;
+}
+
+sub new {
+    my $class = shift;
+    bless {
+        prereqs => [],
+        features => {},
+    }, $class;
+}
+
+sub add_feature {
+    my($self, $identifier, $description) = @_;
+    $self->{features}{$identifier} = { description => $description };
+}
+
+sub add_prereq {
+    my($self, %args) = @_;
+    $self->add( Module::CPANfile::Prereq->new(%args) );
+}
+
+sub add {
+    my($self, $prereq) = @_;
+    push @{$self->{prereqs}}, $prereq;
+}
+
+sub as_cpan_meta {
+    my $self = shift;
+    $self->{cpanmeta} ||= $self->build_cpan_meta;
+}
+
+sub build_cpan_meta {
+    my($self, $identifier) = @_;
+
+    my $prereq_spec = {};
+    $self->prereq_each($identifier, sub {
+        my $prereq = shift;
+        $prereq_spec->{$prereq->phase}{$prereq->type}{$prereq->module} = $prereq->requirement->version;
+    });
+
+    CPAN::Meta::Prereqs->new($prereq_spec);
+}
+
+sub prereq_each {
+    my($self, $identifier, $code) = @_;
+
+    for my $prereq (@{$self->{prereqs}}) {
+        next unless $prereq->match_feature($identifier);
+        $code->($prereq);
+    }
+}
+
+sub merged_requirements {
+    my $self = shift;
+
+    my $reqs = CPAN::Meta::Requirements->new;
+    for my $prereq (@{$self->{prereqs}}) {
+        $reqs->add_string_requirement($prereq->module, $prereq->requirement->version);
+    }
+
+    $reqs;
+}
+
+sub find {
+    my($self, $module) = @_;
+
+    for my $prereq (@{$self->{prereqs}}) {
+        return $prereq if $prereq->module eq $module;
+    }
+
+    return;
+}
+
+sub identifiers {
+    my $self = shift;
+    keys %{$self->{features}};
+}
+
+sub feature {
+    my($self, $identifier) = @_;
+
+    my $data = $self->{features}{$identifier}
+      or Carp::croak("Unknown feature '$identifier'");
+
+    my $prereqs = $self->build_cpan_meta($identifier);
+
+    CPAN::Meta::Feature->new($identifier, {
+        description => $data->{description},
+        prereqs => $prereqs->as_string_hash,
+    });
+}
+
+1;