#!/usr/bin/perl
use strict;
use warnings;
use CPAN::Meta::Requirements;
use Module::CPANfile;
use Getopt::Long qw(:config posix_default no_ignore_case gnu_compat);

my @phases = qw(configure build test develop runtime);
my @types  = qw(requires recommends suggests conflicts);

my %o = map { $_ => 1 } qw/configure build test runtime requires recommends/;

GetOptions(
    "h|help", \$o{help},
    "with-feature=s@",      \$o{with},
    "without-feature=s@",   \$o{without},
    "with-all-features",    \$o{with_all},
    map { ("$_!", \$o{$_}) } (@phases, @types),
);

if ($o{conflicts}) {
    delete $o{$_} for qw/requires recommends suggests/;
}

if ($o{help}) {
    if (eval { require Pod::Usage; 1 }) {
        Pod::Usage::pod2usage(1);
    } else {
        die "Usage: cpanfile-dump\n\nSee perldoc cpanfile-dump for more details.\n";
    }
}
 
my $file = Module::CPANfile->load("cpanfile");

my %excludes = map { $_ => 1 } @{$o{without}};
my @features = grep { !$excludes{$_} } $o{with_all}
    ? ( map { $_->identifier } $file->features )
    : @{$o{with}};

my $prereqs = $file->prereqs_with( @features ); # CPAN::Meta::Prereqs object

my $merged = CPAN::Meta::Requirements->new;

for my $phase ( @phases ) {
    next unless $o{$phase};
    for my $type ( @types ) {
        next unless $o{$type};
        $merged->add_requirements( $prereqs->requirements_for( $phase, $type ) );
    }
}

print "$_\n" for sort $merged->required_modules;


__END__

=head1 NAME

cpanfile-dump - Dump prerequisites from a cpanfile

=head1 SYNOPSIS

  # Install typical required and recommended modules
  cpan `cpanfile-dump`

  # Skip configures phase
  cpan `cpanfile-dump --no-configure`

  # Also include develop phase and suggests type 
  cpan `cpanfile-dump --develop --suggests`

  # Include a feature
  cpan `cpanfile-dump --with-feature=sqlite`

=head1 DESCRIPTION

This script reads prereqs from a F<cpanfile> and dumps a raw list of
them to standard output.  This is useful for piping these as input to
another program that doesn't support reading cpanfile directly,
i.e. C<cpan> or C<cpanp>.

By default, it prints configure, build, test and runtime requirements and
recommendations.  Command line options can be used to modify the default
choices.

This script is distributed with L<Module::CPANfile> since version 1.0002.

=head1 OPTIONS

=over 4

=item --configure, --build, --test, --runtime, --develop

Specify the phase to include/exclude. Defaults to include all but
C<--develop> but you can exclude some phases by specifying the options with
C<--no-> prefix, like C<--no-configure>.

=item --requires, --recommends, --suggests, --conflicts

Specify the type to include/exclude. Defaults to include only C<--requires> and
C<--recommends> but you can exclude some types by specifying the options with
C<--no-> prefix, like C<--no-recommends>.

Specifying C<--conflicts> will turn off all other types (even if specified
on the command line).

=item --with-feature, --with-all-features, --without-feature

    cpanfile-dump --with-feature=sqlite
    cpanfile-dump --with-all-features --without-feature=yaml

Specify features to include in the dump.  C<--with-feature> and C<--without-feature>
may be used more than once.

=back

=head1 NOTES

Because C<cpanm> supports reading cpanfile directly, instead of piping the output of this
program, you're recommended to use C<cpanm --installdeps .> to install modules from cpanfile.

=head1 AUTHOR

David Golden

=head1 SEE ALSO

L<Module::CPANfile> L<cpanfile> L<App::mymeta_requires>

=cut