#!/usr/bin/perl -w

=head1 NAME

module_info - find information about modules

=head1 SYNOPSIS

  module_info [B<-a>] [B<-s>] [B<-p>] [B<-m>] MODULE|FILE...

=head1 DESCRIPTION

List information about the arguments (either module names in the form
C<Module::Name> or paths in the form C<Foo/Bar.pm> or C<foo/bar.pl>).

By default only shows module name, version, directory, absolute path
and a flag indicating if it is a core module. Additional information
can be requested through command line switches.

=over 4

=item B<-s>

Show subroutines created by the module.

=item B<-p>

Show packages created by the module.

=item B<-m>

Show modules C<use()>d by the module.

=item B<-a>

Equivalent to C<-s -p -m>.

=back

=head1 AUTHOR

Mattia Barbon <mbarbon@cpan.org>

=head1 SEE ALSO

L<Module::Info>

=cut

use strict;
use Module::Info;
use Getopt::Long;

my( $show_subroutines, $show_modules, $show_packages, $show_all, $help );

GetOptions( 's' => \$show_subroutines,
            'p' => \$show_packages,
            'm' => \$show_modules,
            'a' => \$show_all,
            'h' => \$help,
          );

if( $help || !@ARGV ) {
    print <<EOT;
Usage: module_info [-a] [-s] [-p] [-m] MODULE|FILE...

    -a Equivalent to -s -p -m
    -h Help message
    -m Show modules use()d by the module
    -p Show packages created by the module
    -s Show subroutines created by the module
EOT
    exit 0;
}

$show_subroutines ||= $show_all;
$show_modules ||= $show_all;
$show_packages ||= $show_all;

my $some_error = 0;

foreach my $module (@ARGV) {
    my $info;

    if( -f $module ) {
        $info = Module::Info->new_from_file($module);
    }
    else {
        $info = Module::Info->new_from_module($module);
    }

    unless( $info ) {
        warn "Can't create Module::Info object for module '$module'";
        $some_error = 1;
        next;
    }

    $info->die_on_compilation_error(1);

    my $name = $info->name || $module;
    my $version = $info->version || '(unknown)';
    my $dir = $info->inc_dir;
    my $file = $info->file;
    my $is_core = $info->is_core ? "yes" : "no";

    print <<EOT;

Name:        $name
Version:     $version
Directory:   $dir
File:        $file
Core module: $is_core
EOT

    my %packages_created;
    my @modules_used;
    my %subroutines;

    eval {
        @modules_used = $info->modules_used if $show_modules;
        %packages_created = $info->package_versions if $show_packages;
        %subroutines = $info->subroutines if $show_subroutines;
    };
    if( $@ ) {
        warn "Compilation failed for module '$module'";
        $some_error = 1;
        next;
    }

    ###########################################################################
    # Modules used
    ###########################################################################
    if( $show_modules ) {
        print "\nModules used:\n";
        foreach my $m (sort @modules_used) {
            print "    $m\n";
        }
        print "    (none)\n" unless @modules_used;
    }

    ###########################################################################
    # Packages defined
    ###########################################################################
    if( $show_packages ) {
        print "\nPackages created:\n";
        foreach my $p (sort keys %packages_created) {
            print "    $p\t";
            print +( defined( $packages_created{$p} ) ?
                                $packages_created{$p} :
                                      '(no version)' );
            print "\n";
        }
        print "    (none)\n" unless keys %packages_created;
    }

    ###########################################################################
    # Subroutines
    ###########################################################################
    if( $show_subroutines ) {
        print "\nSubroutines defined:\n";
        {
            my @subroutines =
              sort  { ( $a->[0] cmp $b->[0] ) || ( $a->[1] cmp $b->[1] ) }
              map   {
                        my($package, $subname) = ($_ =~ m/^(.*)?::(\w+)$/);
                        warn "Strange subroutine '$_'"
                          unless $package || $subname;
                        $package ||= '(unknown)';
                        $subname ||= '(unknown)';
                        [ $package, $subname ];
                    } keys %subroutines;
            my $prev_package = ':'; # impossible
            foreach my $s (@subroutines) {
                my($package, $subname) = @$s;
                if($prev_package ne $package) {
                    $prev_package = $package;
                    print "    $package\n";
                }

                print "        $subname\n";
            }
        }
        print "    (none)\n" unless %subroutines;
    }
}

exit $some_error;