#!/usr/bin/perl
use warnings;
use strict;
use v5.14; # Hashrefs for keys and values.

use JSON;
use Data::Dumper;


sub recurse_hash {
    my ($hash, $found, @findkeys) = @_;
    for my $key (sort { # Defaults go first.
                local $a = q() if '%default' eq $a;
                local $b = q() if '%default' eq $b;
                $a cmp $b;
            } keys %{$hash}) {
        my $value = $hash->{$key};
        if ('HASH' eq ref $value) {
            $found = {%$found, %{ recurse_hash($value, $found, @findkeys) }};
        }
        for my $find (@findkeys) {
            if ($key eq $find) {
                if ('HASH' eq ref $value) {
                    $found->{$key} = [ map $value->{$_}, sort keys $value ];
                } else {
                    $found->{$key} = $value;
                }
            }
        }
    }
    if (@findkeys == keys $found) {
        my $count;
        $count = @{ (grep 'ARRAY' eq ref $_, values $found)[0] // [] };
        $count ||= 1;
        for my $i (0 .. $count - 1) {
            print join(':', map {
                                    'ARRAY' eq ref $_ ? $_->[$i] : $_
                                } @{$found}{@findkeys}), "\n";
        }
        print "\n";
        $found = {};
    }
    return $found;
}


my @keylist = qw(%export_name %filer_device %filer_volume %mount_acl
                 %mount_group %mount_user %mount_opts);

my $string = do { local $/; <DATA> };
my $struct = decode_json($string);

recurse_hash($struct, {}, @keylist);


__DATA__
{
    "%name": "Global Central Configuration file",
    "%description": "A representation of nfs mount points for dev machines",
    "%schema": "schema.conf",
    "@dev": {
        "home_nfs": {
            "%default": {
                "%mount_opts": "nfsvers=3,timeo=600,retrans=2",
                "%mount_user": "root",
                "%mount_group": "root",
                "%mount_acl": "0755"
            },
            "%comment": "----Home NFS Directories----",
            "home-lnk-mpt": {
                "%export_name": "/links",
                "%filer_device": {
                    "@west": "nydevnfs_links",
                    "@ridge": "rnap7750-s"
                },
                "%filer_volume": {
                    "@west": "/vol/links",
                    "@ridge": "/vol/links_c"
                }
            },
            "home7_mpt": {
                "%export_name": "/home7",
                "%filer_device": {
                    "@west": "nydevnfs_home7",
                    "@ridge": "rnap7751-s"
                },
                "%filer_volume": {
                    "@west": "/vol/home7",
                    "@ridge": "/vol/home7_c"
                }
            },
            "home8_mpt": {
                "%export_name": "/home8",
                "%filer_device": {
                    "@west": "nydevnfs_home2",
                    "@ridge": "rnap2114-s"
                },
                "%filer_volume": {
                    "@west": "/vol/home2",
                    "@ridge": "/vol/home2_c"
                }
            }
        }
    }
}