package Getopt::Dakkar::Role::Command;
use Getopt::Dakkar::Style qw(role);
use Getopt::Dakkar::ArgPack;
use Module::Runtime qw(use_module);
with 'Getopt::Dakkar::Role::Piece';
# VERSION
# ABSTRACT: a command

has options => ( is => 'ro', isa => ArrayRef, default => sub { [] } );
has parameters => ( is => 'ro', isa => ArrayRef, default => sub { [] } );
has subcommands => ( is => 'ro', isa => ArrayRef, default => sub { [] } );

has class => ( is => 'ro', isa => Str );
has object => ( is => 'ro', isa => Object );
has op => ( is => 'ro', isa => Str|CodeRef, default => 'merge_with_argpack' );

sub make_stash($self,$argpack) {
    if (my $o = $self->object) { return $o }

    return unless $self->class;

    my $class = use_module($self->class);
    if (my $from_argpack = $class->can('new_from_argpack')) {
        return $class->$from_argpack($argpack);
    }
    else {
        return $class->new();
    }
}

sub parse($self,$args,$stash) {
    $stash = $self->_parse($args,$stash);
    if (my $op = $self->op) {
        return $stash->$op();
    }
    return $stash;
}

sub _parse($self,$args,$stash) {
    my $argpack = Getopt::Dakkar::ArgPack->new({getopt=>$self});
    my @parameters = $self->parameters->@*;
    while ($args->@*) {
        my $this = $args->[0];

        if ($self->_looks_like_option($this)
                and not $self->_is_terminator($this)) {
            if (my $option = $self->_match_option($this)) {
                # ->parse will remove $this (or parts of
                # it, if it's a bundle) and shift its own arguments
                # out of $args
                my $option_value = $option->parse($args,$stash);
                $argpack->options->{$option_value->name} = $option_value;
            }
            else {
                Getopt::Dakkar::X::BadOption->throw({
                    input => $this,
                });
            }
        }
        elsif (my $subcommand = $self->_match_subcommand($this)) {
            shift $args->@*;
            $subcommand->parse($args,$stash);
        }
        elsif ($self->_is_terminator($this)) {
            shift $args->@*;
            for my $parameter ($self->parameters->@*) {
                # ->parse will remove the argument(s) from $args
                my $argument = $parameter->parse($args,$stash);
                $argpack->arguments->{$argument->name} = $argument;
            }

            # if we've parsed all arguments, and there's still stuff
            # in the input, something is wrong: complain
            if ($args->@*) {
                Getopt::Dakkar::X::ExtraArgs->throw({
                    args => $args,
                });
            }
        }
        else {
            my $next_parameter = shift @parameters
                or last;
            my $argument = $next_parameter->parse($args,$stash);
            $argpack->arguments->{$argument->name} = $argument;
        }
    }
    my $new_stash = $self->make_stash($argpack) // $stash;
    my $op = $self->op;
    $new_stash->$op($argpack);

    return $new_stash;
}

sub _is_terminator($self,$arg) { return $arg eq q{--} }
sub _looks_like_option($self,$arg) { return $arg =~ /^-/ }
sub _match_option($self,$arg) {
    for my $option ($self->options->@*) {
        return $option if $option->match($arg);
    }
    return undef;
}
sub _match_subcommand($self,$arg) {
    for my $subcommand ($self->subcommands->@*) {
        return $subcommand if $subcommand->match($arg);
    }
    return undef;
}

sub match($self,$arg) {
    return !! grep { $_ eq $arg } $self->matching_strings->@*;
}