use warnings;
use strict;

use LWP::Simple;
use RPi::WiringPi;
use RPi::WiringPi::Constant qw(:all);

my $continue = 1;
$SIG{INT} = sub { $continue = 0; };

my $pi = RPi::WiringPi->new(setup => 'gpio');

my $lcd = $pi->lcd;

my %args = (
    cols => 16,
    rows => 2,
    bits => 4,
    rs => 21,
    strb => 16,
    d0 => 12,
    d1 => 25, 
    d2 => 24, 
    d3 => 23,
    d4 => 0,
    d5 => 0, 
    d6 => 0, 
    d7 => 0,
);

$lcd->init(%args);

my $button_pin = $pi->pin(26);

$button_pin->pull(PUD_UP);

$button_pin->interrupt_set(
    EDGE_FALLING, 
    'button_press'
);

my $button_presses = 0;
my ($posts, $xp, $next);

while ($continue){
    my (
        $sec,$min,$hour,$mday,$mon,
        $year,$wday,$yday,$isdst
    ) = localtime();
    $min = "0$min" if length $min == 1;
    
    ($posts, $xp) = perlmonks();
    $next = 12000 - $xp;

    $lcd->position(0, 0);
    $lcd->print("p: $posts"); 
   
    display_xp();

    $lcd->position(11, 0);
    $lcd->print("$hour:$min");

    print "$hour:$min posts: $posts, " .
          "xp: $xp, next lvl: $next\n";

    sleep 60;
}

$lcd->clear;
$pi->cleanup;

sub button_press {
    print "button pressed\n";
    $button_presses++;
    display_xp();
}
sub display_xp {
    $lcd->position(0, 1);
    if ($button_presses % 2){
        $lcd->print("r: $next");
    }
    else {
        $lcd->print("x: $xp");
    }
}
sub perlmonks {
    my $url = "http://perlmonks.org/?node_id=789891";
    my $page = get $url;
    my @content = split /\n/, $page;

    my ($xp, $posts);
    my $i = 0;

    for (@content){
        if (/Experience:/){
            my $line = $i;
            $line += 2;
            $xp = $1 if $content[$line] =~ /(\d+)/;
        }
        if (/Writeups:/){
            my $line = $i;
            $line += 2;
            $posts = $1 if $content[$line] =~ />(\d+)/;
        }
        $i++;
    }
    return ($posts, $xp);
}