#!/usr/bin/env perl

use strict;
use warnings;

my %device_info = (
    DEVA => [qw{a b c}],
    DEVQ => [qw{q r s}],
    DEVX => [qw{x y z}],
);

my $json = [
    {
        read => [
            { qw{r u3 s f1 q s4} },
            { qw{q s6 r u4 s f2} },
        ],
        dev => 'DEVQ',
        rep => 'A',
    },
    {
        read => [
            { qw{y u3 z f1 x s4} },
            { qw{x s6 y u4 z f2} },
        ],
        dev => 'DEVX',
        rep => 'B',
    },
    {
        read => [
            { qw{b u3 c f1 a s4} },
            { qw{a s6 b u4 c f2} },
        ],
        dev => 'DEVA',
        rep => 'C',
    },
];

for my $report (@$json) {
    print "Report $report->{rep} - ";

    my $device = $report->{dev};
    print "Device $device\n";

    my @order = @{$device_info{$device}};

    for my $readings (@{$report->{read}}) {
        print "\t@{$readings}{@order}\n";
    }
}

##</code><code>##

Report A - Device DEVQ
        s4 u3 f1
        s6 u4 f2
Report B - Device DEVX
        s4 u3 f1
        s6 u4 f2
Report C - Device DEVA
        s4 u3 f1
        s6 u4 f2