package XSConf;

use XML::Simple;
use strict;
use warnings;

my $config;

sub import {
    shift;
    $config or $config = XMLin(shift) if @_;
    $XSConf::strict    = 1            if @_;
    return; # don't give $config away
}   

my $token;
our $AUTOLOAD;

sub AUTOLOAD {
    my $package = shift;
    local $_    = $AUTOLOAD;
    s/.*:://;

    /^DESTROY$/ and return; # you may NOT use DESTROY in your config
    /^config$/  and $token = $config and return $package;
    /^_type$/   and return ref $token || 'SCALAR';
    /^_keys$/   and return keys %$token;
    /^_values$/ and return map { "$_" } values %$token;
    /^_each$/   and return map { "$_" } each %$token;
    /^_len/     and return scalar @$token;
    /^_last$/   and return $#$token;
    /^_elems$/  and return map { "$_" } @$token;

    my $thing;
    if ( ref $token eq 'HASH' ) {
        die "$_ doesn't exist in $package\n"
            unless exists $token->{$_};
        $thing = $token->{$_};
    } elsif ( ref $token eq 'ARRAY' ) {
        s/^_//;
        die "index $_ out of range\n"
            if $_ > $#$token;
        $thing = $token->[$_];
    }
    ref $thing and $token = $thing or return bless \$thing, 'XSConf::Str';

    return $package;
}

package XSConf::Str;

use overload '""' => \&str, fallback => 1;

sub str { ${$_[0]} }

our $AUTOLOAD;

sub AUTOLOAD {
    return if $AUTOLOAD eq 'XSConf::Str::DESTROY';
    $AUTOLOAD =~ s/.*:://;
    my @caller = caller;
    die "you cannot invoke the method '$AUTOLOAD' on the string '$_[0]'"
     . " at $caller[1] line $caller[2]\n" if $XSConf::strict;
    $_[0];
}
1;