use JSON::PP;
use HTTP::Tiny;

sub ddg_clean
{
    my $res = shift;
    for my $k (keys %$res) {
        delete $res->{$k} if $res->{$k} eq '';
        if (ref $res->{$k} eq 'HASH') {
            ddg_clean($res->{$k});
            delete $res->{$k} unless keys %{$res->{$k}};
        } elsif (ref $res->{$k} eq 'ARRAY') {
            ddg_clean($_) for @{$res->{$k}};
            delete $res->{$k} unless @{$res->{$k}};
        }
    }
}

sub ddg
{
    my $q = shift;
    my $h = new HTTP::Tiny;
    my $res = $h->get(
        'http://api.duckduckgo.com/?'
            . $h->www_form_urlencode({ format => 'json', q => $q }));
    die unless $res->{success};
    ddg_clean($res = decode_json($res->{content}));
    $res;
}

sub INDENT() { '    ' }

sub ddg_format
{
    my ($it, $lev) = @_;
    if (!ref $it) {
        wrap(INDENT x $lev, INDENT x $lev, $it);
    } elsif (ref $it eq 'HASH') {
        join "\n", map {
            my $val = ddg_format($it->{$_}, $lev+1);
            if ($val =~ /\n/) {
                INDENT x $lev . "$_:\n$val";
            } else {
                $val =~ s/^\s+//;
                INDENT x $lev . "$_: $val";
            }
        } sort keys %$it;
    } else {
        join "\n", map { ddg_format($_, $lev+1) } @$it;
    }
}

if (!defined caller) {
    eval 'use Text::Wrap';
    print ddg_format(ddg("@ARGV"), 0), "\n";
}