#!/usr/bin/perl

use strict;
use warnings;

use SDL;
use SDL::App;
use SDL::Surface;
use SDL::Cursor;
use SDL::Event;
use SDL::Mixer;
use SDL::Sound;
use SDL::TTFont;

# Constants
my $padding = 3;

# Find and handle arguments 
my $numArgs = $#ARGV + 1;
my ($width, $height, $box_size) = ( 11, 3, 80);

my $app = new SDL::App(
        -title=>'Keyboard',
        -width=>$width * $box_size + $padding,
        -height=>$height * $box_size + $padding,
        -depth=>32,
        -flags=>SDL_DOUBLEBUF | SDL_HWSURFACE | SDL_HWACCEL,
);

my $mixer = new SDL::Mixer(-frequency=>44100, -channels=>2, -size=>1024);

my @rects = ();
my @sounds = ();
my @modified_areas = ();
my ($colorOn, $colorOff);
my $lastPress = 0;
my $actions_playing = {
    SDL_KEYDOWN() => \&process_event_playing_keypress,
};

my $actions = $actions_playing;
&event_loop();

sub event_loop {
    my $next_heartbeat = $app->ticks;
    my $event = new SDL::Event;
    
    # Load Sounds
    for( my $i = 1; $i <= 11; $i ++ )
    {
       @sounds = (@sounds, 
                 new SDL::Sound("./instruments/guitar/I$i.wav"),
                 new SDL::Sound("./instruments/piano/I$i.wav"),
                 new SDL::Sound("./instruments/drums/I$i.wav"));
    }
    $colorOff = new SDL::Color(-r=>95, -g=>95, -b=>95);
    $colorOn = new SDL::Color(-r=>25, -g=>25, -b=>150);

    # Build Boxes
    for (my $i = 0; $i < $width; $i ++ )
    {
       for (my $j = 0; $j < $height; $j ++ )
       {
          @rects = (@rects, new SDL::Rect(
             -x=>$i * $box_size + $padding, 
             -y=>$j * $box_size + $padding,
             -width=>$box_size - $padding,
             -height=>$box_size - $padding
           ));
	}
    }
    clear_boxes();
    $app->update(@modified_areas);
    MAIN_LOOP:
    while(1) {
        while ($event->poll) {
            my $type = $event->type();

            last MAIN_LOOP if ($type == SDL_QUIT);
            last MAIN_LOOP if ($type == SDL_KEYDOWN && $event->key_name() eq 'escape');

            if ( exists($actions->{$type}) && ref( $actions->{$type} ) eq "CODE" ) {
                $actions->{$type}->($event);
            }
        }
        $app->delay(5);
    }
}

sub clear_boxes()
{
    for ( my $i = 0; $i < $width * $height; $i ++ )
    {
       $app->fill($rects[$i], $colorOff);
       push(@modified_areas, $rects[$i]);
    }
}

sub handle_press
{
  my ($key) = @_;
  $mixer->play_channel(-1, $sounds[$key], 0);

  $app->fill($rects[$lastPress], $colorOff);
  if ( $key % 3 == 0 )
  {
     $app->fill($rects[$key + 2], $colorOn);
     $lastPress = $key + 2;
  } else {
     $app->fill($rects[$key - 1], $colorOn);
     $lastPress = $key - 1;
  }

}

sub process_event_playing_keypress 
{
    my $event = shift;

    my $key_name = $event->key_name();

    # Piano
    if($key_name eq "q") { handle_press(1); } 
    if($key_name eq "w") { handle_press(4); }
    if($key_name eq "e") { handle_press(7); }
    if($key_name eq "r") { handle_press(10); }
    if($key_name eq "t") { handle_press(13); }
    if($key_name eq "y") { handle_press(16); }
    if($key_name eq "u") { handle_press(19); }
    if($key_name eq "i") { handle_press(22); }
    if($key_name eq "o") { handle_press(25); }
    if($key_name eq "p") { handle_press(28); }
    if($key_name eq "[") { handle_press(31); }

    # Drums
    if($key_name eq "a") { handle_press(2); } 
    if($key_name eq "s") { handle_press(5); } 
    if($key_name eq "d") { handle_press(8); } 
    if($key_name eq "f") { handle_press(11); } 
    if($key_name eq "g") { handle_press(14); } 
    if($key_name eq "h") { handle_press(17); } 
    if($key_name eq "j") { handle_press(20); } 
    if($key_name eq "k") { handle_press(23); } 
    if($key_name eq "l") { handle_press(26); } 
    if($key_name eq ";") { handle_press(29); } 
    if($key_name eq "'") { handle_press(32); } 
   
    # Guitar
    if($key_name eq "z") { handle_press(0); } 
    if($key_name eq "x") { handle_press(3); } 
    if($key_name eq "c") { handle_press(6); } 
    if($key_name eq "v") { handle_press(9); } 
    if($key_name eq "b") { handle_press(12); } 
    if($key_name eq "n") { handle_press(15); } 
    if($key_name eq "m") { handle_press(18); } 
    if($key_name eq ",") { handle_press(21); } 
    if($key_name eq ".") { handle_press(24); } 
    if($key_name eq "/") { handle_press(27); } 
    if($key_name eq "right shift") { handle_press(30); } 
    
    $app->update(@modified_areas);
 }