package App::CLI::Command;
use strict;
use warnings;
use Locale::Maketext::Simple;
use Carp ();
use App::CLI::Helper;
use Class::Load qw( load_class );
use Scalar::Util qw( weaken );

=head1 NAME

App::CLI::Command - Base class for App::CLI commands

=head1 SYNOPSIS

    package MyApp::List;
    use base qw(App::CLI::Command);

    use constant options => (
        'verbose'   => 'verbose',
        'n|name=s'  => 'name',
    );

    sub run {
        my ( $self, $arg ) = @_;

        print "verbose" if $self->{verbose};

        my $name = $self->{name}; # get arg following long option --name

        # anything you want this command do
    }

    # See App::CLI for information of how to invoke (sub)command.

=head1 DESCRIPTION


=cut

use constant subcommands => ();
use constant options     => ();

sub new {
    my $class = shift;
    bless {@_}, $class;
}

sub command_options {
    ( ( map { $_ => $_ } $_[0]->subcommands ), $_[0]->options );
}

sub run_command {
    my $self = shift;
    $self->run(@_);
}

sub run {
    my $class = shift;
    Carp::croak ref($class) . " does not implement mandatory method 'run'\n";
}

=head3 subcommand()

    return old genre subcommand of $self;

=cut

sub subcommand {
    my $self = shift;
    my @cmd  = $self->subcommands;
    @cmd = values %{ { $self->options } } if @cmd && $cmd[0] eq '*';
    my $subcmd = undef;
    for ( grep { $self->{$_} } @cmd ) {
        no strict 'refs';
        if ( exists ${ ref($self) . '::' }{ $_ . '::' } ) {
            my %data = %{$self};
            $subcmd = bless( {%data}, ( ref($self) . "::$_" ) );
            last;
        }
    }
    $subcmd ? $subcmd : $self;
}

=head3 cascading()

Return instance of cascading subcommand invoked if it was listed in your
constant subcommands.

=cut

sub cascading {
    my $self = shift;
    if ( my $subcmd = $self->cascadable ) {
        shift @ARGV;
        my %data = %{$self};
        return bless {%data}, $subcmd;
    }
    else {
        die $self->error_cmd( $ARGV[0] );
    }
}

=head3 cascadable()

Return package name of subcommand if the subcommand invoked is in your
constant subcommands, otherwise, return C<undef>.

=cut

sub cascadable {
    my $self = shift;
    my $class = ref $self || $self;
    for ( $self->subcommands ) {
        no strict 'refs';
        my $package_name = $class . '::' . $_;
        load_class $package_name;
        if ( $ARGV[0]
            && (ucfirst( $ARGV[0] ) eq $_)
            && exists ${ $class . '::' }{ $_ . '::' } )
        {
            return $package_name;
        }
    }
    return undef;
}

=head3 app

Return the object referring to the current app.

=cut

sub app {
    my $self = shift;

    if (@_) {
        $self->{app} = shift;
        weaken( $self->{app} );
    }

    return $self->{app};
}

=head3 brief_usage ($file)

Display a one-line brief usage of the command object.  Optionally, a file
could be given to extract the usage from the POD.

=cut

sub brief_usage {
    my ( $self, $file ) = @_;
    open my ($podfh), '<', ( $file || $self->filename ) or return;
    local $/ = undef;
    my $buf  = <$podfh>;
    my $base = ref $self->app;
    my $indent = "    ";
    if ( $buf =~ /^=head1\s+NAME\s*\Q$base\E::(\w+)( - .+)$/m ) {
        print $indent, loc( lc($1) . $2 ), "\n";
    }
    else {
        my $cmd = $file || $self->filename;
        $cmd =~ s/^(?:.*)\/(.*?).pm$/$1/;
        print $indent, lc($cmd), " - ", loc("undocumented") . "\n";
    }
    close $podfh;
}

=head3 usage ($want_detail)

Display usage.  If C<$want_detail> is true, the C<DESCRIPTION>
section is displayed as well.

=cut

sub usage {
    my ( $self, $want_detail ) = @_;
    my $fname = $self->filename;
    my ($cmd) = $fname =~ m{\W(\w+)\.pm$};
    require Pod::Simple::Text;
    my $parser = Pod::Simple::Text->new;
    my $buf;
    $parser->output_string( \$buf );
    $parser->parse_file($fname);

    my $base = ref $self->app;
    $buf =~ s/\Q$base\E::(\w+)/\l$1/g;
    $buf =~ s/^AUTHORS.*//sm;
    $buf =~ s/^DESCRIPTION.*//sm unless $want_detail;
    print $self->loc_text($buf);
}

=head3 loc_text $text

Localizes the body of (formatted) text in C<$text> and returns the
localized version.

=cut

sub loc_text {
    my $self = shift;
    my $buf  = shift;

    my $out = "";
    foreach my $line ( split( /\n\n+/, $buf, -1 ) ) {
        if ( my @lines = $line =~ /^( {4}\s+.+\s*)$/mg ) {
            foreach my $chunk (@lines) {
                $chunk =~ /^(\s*)(.+?)( *)(: .+?)?(\s*)$/ or next;
                my $spaces = $3;
                my $loc = $1 . loc( $2 . ( $4 || '' ) ) . $5;
                $loc =~ s/: /$spaces: / if $spaces;
                $out .= $loc . "\n";
            }
            $out .= "\n";
        }
        elsif ( $line =~ /^(\s+)(\w+ - .*)$/ ) {
            $out .= $1 . loc($2) . "\n\n";
        }
        elsif ( length $line ) {
            $out .= loc($line) . "\n\n";
        }
    }
    return $out;
}

=head3 filename

Return the filename for the command module.

=cut

sub filename {
    my $self  = shift;
    my $fname = ref($self);
    $fname =~ s{::[a-z]+$}{};    # subcommand
    $fname =~ s{::}{/}g;
    return $INC{"$fname.pm"};
}

=head1 SEE ALSO

L<App::CLI>, L<Getopt::Long>

=head1 AUTHORS

Chia-liang Kao E<lt>clkao@clkao.orgE<gt>

Cornelius Lin  E<lt>cornelius.howl@gmail.comE<gt>

Shelling       E<lt>navyblueshellingford@gmail.comE<gt>

Paul Cochrane  E<lt>paul@liekut.deE<gt> (current maintainer)

=head1 COPYRIGHT

Copyright 2005-2006 by Chia-liang Kao E<lt>clkao@clkao.orgE<gt>.

This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.

See L<http://www.perl.com/perl/misc/Artistic.html>

=cut

1;