package GSPSupport;

use strict;
use warnings;

use XML::Simple;
use Carp;
use English;

sub parse {
    open(my $ifh, '<', 'projectname.txt') or croak($!);
    my $projectname = <$ifh>;
    close $ifh;

    chomp $projectname;
    if(!length($projectname)) {
        croak("No projectname given!");
    }

    my $devicesfile = '/home/cavac/src/gardenspaceagency/missioncontrol/devices.xml';
    if(!-f $devicesfile) {
        $devicesfile = '../devices.xml';
    }

    my $deviceconfig = XMLin($devicesfile);
    my $devices = $deviceconfig->{device};

    if(!defined($devices->{$projectname})) {
        croak("Unknown project $projectname");
    }

    my $config = $devices->{$projectname};

    my @rf24routing;
    push @rf24routing, $config->{id};

    while((scalar @rf24routing < 5)) {
        push @rf24routing, 0;
    }
    $config->{rf24routing} = \@rf24routing;

    return $config;

}

sub loadClacksConfig {
    my $configfile = '/home/cavac/src/clacksconfig.xml';
    if(!-f $configfile) {
        $configfile = '../clacksconfig.xml';
    }

    my $config = XMLin($configfile);

    return $config;
}

sub emptyframe {
    my $config = shift;

    my @outframe = (0) x 30;

    # Sender, reciever
    $outframe[0] = 0x01; # Linksender MODEM
    for(my $i = 0; $i < 5; $i++) {
        $outframe[$i + 1] = $config->{rf24routing}->[$i];
    }

    $outframe[6] = 0x01; # Real sender MODEM
    $outframe[7] = $config->{id}; # Real reciever 

    return @outframe;
}

sub frame2packet {
    my @frame = @_;

    my $packet = '';
    foreach my $byte (@frame) {
        my $lowbyte = ($byte & 0x0f) + 65;
        my $highbyte = ($byte >> 4) + 65;

        $packet .= chr($highbyte);
        $packet .= chr($lowbyte);
    }

    return $packet;
}

sub packet2frame {
    my $packet = shift;

    my @chars = split//, $packet;
    my @frame = ();

    # Decode to bytes
    while(@chars) {
        my $high = shift @chars;
        my $low = shift @chars;

        my $val = ((ord($high) - 65) << 4) + (ord($low) - 65);
        push @frame, $val;
    }

    return @frame;
}

sub decodeErrorFrame {
    my @frame = @_;

    if($frame[12] == 1) {
        print "MODBUS ERROR\n";
    } elsif($frame[12] == 2) {
        print "INVALID PAYLOAD_LENGTH ERROR\n";
    } elsif($frame[12] == 3) {
        print "MODBUS_SLAVE_NOT_SET ERROR\n";
    } elsif($frame[12] == 4) {
        print "REBOOT_DETECTED ERROR\n";
    } elsif($frame[12] == 5) {
        print "REQUEST_REJECTED ERROR\n";
    } elsif($frame[12] == 6) {
        print "MOSFET_TEMPERATURE ERROR\n";
    }

    return;
}

sub slurpBinFile {
    my $fname = shift;

    # Read in file in binary mode, slurping it into a single scalar.
    # We have to make sure we use binmode *and* turn on the line termination variable completly
    # to work around the multiple idiosynchrasies of Perl on Windows
    open(my $fh, "<", $fname) or croak($ERRNO);
    local $INPUT_RECORD_SEPARATOR = undef;
    binmode($fh);
    my $data = <$fh>;
    close($fh);

    return $data;
}

1;