#!/usr/bin/perl
use strict;
use warnings;

# Local modules
use Cwd qw(abs_path);
use File::Basename qw(dirname);
use lib dirname(abs_path($0));
use DMX;

# User config
my %DIM = (
    'OFF' => [
        { 'channel' => 26, 'value' => 0, 'time' => 0 },
        { 'channel' => 67, 'value' => 0, 'time' => 0 },
    ],
    'ON' => [
        { 'channel' => 26, 'value' => 255, 'time' => 0 },
        { 'channel' => 67, 'value' => 255, 'time' => 0 },
    ],
);

# App config
my $DATA_DIR     = DMX::dataDir();
my $STATE_SOCK   = 'COMFORT';
my $OUTPUT_FILE  = $DATA_DIR . $STATE_SOCK;
my $PUSH_TIMEOUT = 20;
my $PULL_TIMEOUT = $PUSH_TIMEOUT * 3;
my $DELAY        = $PULL_TIMEOUT / 2;

# Debug
my $DEBUG = 0;
if ($ENV{'DEBUG'}) {
    $DEBUG = 1;
}

# State
my $state       = 'OFF';
my $stateLast   = $state;
my $masterState = 'OFF';
my %exists      = ();
my %mtime       = ();
my $pushLast    = 0;
my $pullLast    = time();
my $update      = 0;

# Always force the heater into OFF at launch
$state = 'OFF';
DMX::applyDataset($DIM{$state}, $state, $OUTPUT_FILE);

# Sockets
DMX::stateSocket($STATE_SOCK);
DMX::stateSubscribe($STATE_SOCK);

# Loop forever
while (1) {

    # Wait for state updates
    my $cmdState = DMX::readState($DELAY, \%exists, \%mtime, undef());

    # Avoid repeated calls to time()
    my $now = time();

    # Record only valid states
    if (defined($cmdState)) {
        $masterState = $cmdState;
        $pullLast    = $now;
    }

    # Die if we don't see regular updates
    if ($now - $pullLast > $PULL_TIMEOUT) {
        die(    'No update on state socket in past '
              . $PULL_TIMEOUT
              . " seconds. Exiting...\n");
    }

    # Calculate the new state
    $stateLast = $state;
    if ($masterState ne 'OFF') {
        $state = 'ON';
    } elsif (exists($exists{'NO_MOTION'}) && $exists{'NO_MOTION'}) {
        $state = 'ON';
    } else {
        $state = 'OFF';
    }

    # Force updates on a periodic basis
    if (!$update && $now - $pushLast > $PUSH_TIMEOUT) {
        if ($DEBUG) {
            print STDERR "Forcing periodic update\n";
        }
        $update = 1;
    }

    # Force updates on any state change
    if (!$update && $stateLast ne $state) {
        if ($DEBUG) {
            print STDERR 'State change: ' . $stateLast . ' => ' . $state . "\n";
        }
        $update = 1;
    }

    # Update the DMX chain
    if ($update) {

        # Update
        DMX::applyDataset($DIM{$state}, $state, $OUTPUT_FILE);

        # Update the push time
        $pushLast = $now;

        # Clear the update flag
        $update = 0;
    }
}