Switched to Mojo::Base, added comments

discordnp.pl

@@ -1,34 +1,39 @@
 #!/usr/bin/env perl
 
-use v5.10;
-use warnings;
-use strict;
-
+use Mojo::Base -base;
 use Mojo::WebService::LastFM;
 use Mojo::Discord;
-use Config::Tiny;
 use Mojo::IOLoop;
+use Config::Tiny;
 
+# Read the config file
+# Default to "config.ini" unless one is passed in as an argument
 my $config = Config::Tiny->new;
 my $config_file = $ARGV[0] // 'config.ini';
-
 $config = Config::Tiny->read( $config_file, 'utf8' );
 say localtime(time) . " - Loaded Config: $config_file";
 
+# Instantiate the current and previously played tracks to empty strings
+my $np = "";
 my $last_played = "";
+
+# How often are we polling Last.FM for new statuses?
 my $interval = $config->{'lastfm'}->{'interval'};
 
+# Get the user's Discord token from the config
 my $discord_token = $config->{'discord'}->{'token'};
-$discord_token =~ s/^(?:token:)?"?"?(.*?)"?"?$/$1/;  # Extract the actual token if they user copypasted the entire value from their browser.
+$discord_token =~ s/^(?:token:)?"?"?(.*?)"?"?$/$1/;  # Extract the actual token if they user copypasted the entire field from their browser.
 
+# Get the user's Last.FM API Key from the config
 my $lastfm_key = $config->{'lastfm'}->{'api_key'};
 $lastfm_key =~ s/^"?(.*?)"?$/$1/;
 
+# Set up the Mojo::WebService::LastFM object with the provided key
 my $lastfm = Mojo::WebService::LastFM->new(
     api_key     => $lastfm_key
 );
 
-
+# Set up the Mojo::Discord object with the provided token
 my $discord = Mojo::Discord->new(
     # Ctrl+Shift+I and type localStorage.token in the console to get the user token.
     'token'         => $discord_token,
@@ -37,27 +42,36 @@
     'url'           => 'https://github.com/vsterminus',
     'version'       => '1.0',
     'verbose'       => $config->{'discord'}->{'verbose'},
-    'reconnect'     => 1,
-    'callbacks'     => {
-        'READY'  => \&on_ready,
+    'reconnect'     => 0,
+    'callbacks'     => {    # We really only need to know when Discord is connected and disconnected. Nothing else matters here.
+        'READY'     => \&on_ready,
+        'FINISH'    => \&on_finish, 
     },
 );
 
+# Poll Last.FM and update the user's Discord status if the track has changed.
 sub update_status
 {
+    # Mojo::WebService::LastFM lets us optionally specify a format to return the results in.
+    # Without it we would just get a hashref back containing all of the values.
+    # For this script all we need is Artist - Title.
+    # 
+    # This call is also optionally non-blocking if a callback function is provided, which we are doing.
     $lastfm->nowplaying({   user     => $config->{'lastfm'}->{'username'}, 
                             format   => "%artist% - %title%", 
                             callback => sub 
     {
-        my $np = shift;
+        my $nowplaying = shift;
 
-        if ( defined $np )
+        if ( defined $nowplaying )
         {
-            if ( $np ne $last_played )
+            if ( $nowplaying ne $last_played )
             {
-                $discord->status_update({'game' => $np});
-                say localtime(time) . " - Status Updated: $np";
-                $last_played = $np;
+                # If we received a valid response from Last.FM and a new song is playing, update our info.
+                $np = $nowplaying;
+
+                # Now connect to discord. Receiving the READY packet from Discord will trigger the status update automatically.
+                $discord->init(); 
             }
         }
         else
@@ -70,21 +84,40 @@ sub update_status
 
 }
 
+# After connecting to Discord it will send a READY packet full of information.
+# We don't care what is in that packet, only that Discord accepted our connection.
+# It tells us that it is now safe to send a status update.
 sub on_ready
 {
     my ($hash) = @_;
 
     say localtime(time) . " - Connected to Discord.";
 
     # Update status immediately
-    update_status();
+    $discord->status_update({'game' => $np});
+    say localtime(time) . " - Status Updated: $np";
+    $last_played = $np;
+
+    # Once the status update has been sent, immediately disconnect from Discord again.
+    # This ensures that we won't block Android notifications.
+    # (If we stayed connected Discord would think we were actively watching the chat and would not trigger the push notification to mobile clients)
+    $discord->disconnect("Status Updated");
+}
 
-    # This will trigger the Last.FM lookup timer
-    Mojo::IOLoop->recurring($config->{'lastfm'}->{'interval'} => sub { update_status(); });
+# This triggers when Discord disconnects.
+# We could do more validation here, but for now this is enough.
+sub on_finish
+{
+    say localtime(time) . " - Disconnected from Discord.";
 }
 
-# Set up the Discord Gateway Websocket connection
-$discord->init();
+# This is the first line of code executed by the script (aside from setting variables).
+# It should trigger the first poll to Last.FM immediately.
+update_status();
+
+# Now set up a recurring timer to periodically poll Last.FM for new updates.
+Mojo::IOLoop->recurring($config->{'lastfm'}->{'interval'} => sub { update_status(); });
 
 # Start the IOLoop. This will connect to discord and begin the LastFM timers.
+# Anything below this line will not execute until the IOLoop completes (which is never).
 Mojo::IOLoop->start unless Mojo::IOLoop->is_running;