#!/usr/bin/env perl -l

use strict;
use warnings;
use lib '.'; 

use Decoupled qw{
    preprocess_complex_message
    handle_generic_message
};

my %decode_type = (
    A => sub { 
        handle_generic_message(
            A => preprocess_complex_message($_[0])
        )
    },
    B => sub { 
        handle_generic_message(B => $_[0])
    },
);

while (<DATA>) {
    chomp;
    my ($type, $msg) = split /\s+/, $_, 2;
    my $decoded = $decode_type{$type}->($msg);
    print $decoded;
}

__DATA__
B message B1
A more complex message A1
B message B2