From b6da79a0bc1289f2a6064a6b3ffcd0c2333f2c97 Mon Sep 17 00:00:00 2001
From: Patrick Spek <p.spek@tyil.nl>
Date: Wed, 5 May 2021 11:03:32 +0200
Subject: Initial commit

---
 lib/IRC/Client/Handler.rakumod | 174 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 174 insertions(+)
 create mode 100644 lib/IRC/Client/Handler.rakumod

(limited to 'lib/IRC/Client/Handler.rakumod')

diff --git a/lib/IRC/Client/Handler.rakumod b/lib/IRC/Client/Handler.rakumod
new file mode 100644
index 0000000..c966099
--- /dev/null
+++ b/lib/IRC/Client/Handler.rakumod
@@ -0,0 +1,174 @@
+#! /usr/bin/env false
+
+use v6.d;
+
+use IRC::Client::Message;
+use IRC::Client::Plugin;
+
+use Log;
+
+#| This class handles incoming messages, formats a context from them and
+#| dispatches it on to any registered plugin that can handle it.
+unit class IRC::Client::Handler;
+
+#| Handle numeric commands.
+multi method handle (
+	$event where { $_.command ~~ / \d ** 3/ },
+) {
+	my @events;
+
+	# Special cases for IRC::Client
+	@events.append('irc-connected' => $event.irc) if $event.command eq '001';
+	@events.append('irc-ready' => $event.irc) if $event.command eq '376';
+	@events.append('irc-ready' => $event.irc) if $event.command eq '422';
+
+	# Regular events, handles in the regular way
+	@events.append("irc-n{$event.command}" => $event);
+	@events.append('irc-numeric' => $event);
+	@events.append('irc-all' => $event);
+
+	self.dispatch(@events, $event.irc);
+}
+
+#| Handle PRIVMSG and NOTICE commands.
+multi method handle (
+	$event where { $_.command ∈ <PRIVMSG NOTICE> }
+) {
+	my @events;
+	my $stripped;
+
+	# If the message starts with the name of the client, it should dispatch
+	# an irc-addressed event.
+	if ($event.params[*-1] ~~ / ^ ( "{$event.irc.nick}" <[:;,]> <.ws> ) /) {
+		$stripped = $event.set-param(*-1, $event.params[*-1].substr($0.chars));
+	}
+
+
+	# A private message to the client should dispatch an irc-to-me event,
+	# optionally stripping away the client's current nickname from the
+	# start.
+	if ($event.params[0] eq $event.irc.nick) {
+		@events.append('irc-to-me' => $stripped // $event);
+	}
+
+	# A message to a public channel prefixed with the client's current
+	# nickname is both an irc-to-me event, and an irc-addressed event.
+	if ($event.params[0] ne $event.irc.nick && $stripped) {
+		@events.append('irc-to-me' => $stripped);
+		@events.append('irc-addressed' => $stripped);
+	}
+
+	@events.append("irc-{$event.command.fc}-me" => $event) if $event.params[0] eq $event.irc.nick;
+	@events.append('irc-mentioned' => $event) if $event.params[*-1].words ∋ $event.irc.nick;
+	@events.append("irc-{$event.command.fc}-channel" => $event) if $event.params[0] ~~ / ^ <[#&]> /;
+	@events.append("irc-{$event.command.fc}" => $event);
+	@events.append('irc-all' => $event);
+
+	self.dispatch(@events, $event.irc);
+}
+
+#| Handle MODE commands.
+multi method handle (
+	$event where { $_.command eq 'MODE' }
+) {
+	my @events;
+
+	@events.append('irc-mode-me' => $event) if $event.params[0] eq $event.irc.nick;
+	@events.append('irc-mode-channel' => $event) if $event.params[0] ~~ / ^ <[#&]> /;
+	@events.append('irc-mode' => $event);
+	@events.append('irc-all' => $event);
+
+	self.dispatch(@events, $event.irc);
+}
+
+#| Handle all IRC commands. Note that the order in which events are appended
+#| does matter, the most "narrow" event should always come first, getting
+#| broader as we go down the list.
+multi method handle (
+	$event,
+) {
+	my @events;
+
+	@events.append("irc-{$event.command.fc}" => $event);
+	@events.append('irc-all' => $event);
+
+	self.dispatch(@events, $event.irc);
+}
+
+#| Dispatch the message to all plugins.
+method dispatch (
+	@events,
+	$client, #= IRC::Client, but can't `use` this due to circular references
+) {
+	my @plugins = $client.plugins;
+
+	# Loop over all the plugins, and dispatch to each of them on a seperate
+	# thread. This allows plugins to take their sweet time, while not being
+	# in any other plugins' way.
+	for $client.plugins -> $plugin {
+		start {
+			CATCH {
+				default {
+					my $exception = $_;
+					.emergency($exception.gist.lines.map(*.trim-trailing).join("\n")) with $Log::instance;
+				}
+			}
+
+			self.dispatch-plugin(@events, $plugin)
+		}
+	}
+}
+
+#| Dispatch the message to all plugin methods that can handle them.
+method dispatch-plugin (
+	@events,
+	IRC::Client::Plugin $plugin,
+) {
+	for @events -> $event {
+		my $method = $event.key;
+		my $payload = $event.value;
+
+		# Check for available methods to handle this payload.
+		my @methods = $plugin.^can($method)
+			.map(*.candidates)
+			.flat
+			.grep(*.cando(\($plugin, $payload)))
+			;
+
+		# Nothing to do if nothing was found.
+		next unless @methods;
+
+		.debug("Dispatching to {$plugin.^name}.$method") with $Log::instance;
+
+		my $response = $plugin."$method"($payload);
+
+		next unless $payload ~~ IRC::Client::Message;
+
+		# Depending on the return value of the method, something can be
+		# done.
+		given ($response) {
+			when Str {
+				$payload.reply($response);
+				last;
+			}
+		}
+	}
+}
+
+=begin pod
+
+=NAME    IRC::Client::Handler
+=AUTHOR  Patrick Spek <~tyil/raku-devel@lists.sr.ht>
+=VERSION 0.0.0
+
+=head1 Synopsis
+
+=head1 Description
+
+=head1 Examples
+
+=head1 See also
+
+=end pod
+
+# vim: ft=perl6 noet
-- 
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