IRCClient: Start working on a simple graphical IRC client.

This will be a nice way to exercise both LibGUI and the TCP/IP support. :^)

Applications/IRCClient/IRCClient.h

@@ -0,0 +1,65 @@
+#pragma once
+
+#include <AK/AKString.h>
+#include <AK/HashMap.h>
+#include <AK/CircularQueue.h>
+#include <AK/Function.h>
+
+class IRCChannel;
+class IRCQuery;
+class GNotifier;
+
+class IRCClient {
+public:
+    IRCClient(const String& address, int port = 6667);
+    ~IRCClient();
+
+    bool connect();
+
+    String hostname() const { return m_hostname; }
+    int port() const { return m_port; }
+
+    String nickname() const { return m_nickname; }
+
+    void join_channel(const String&);
+
+    bool is_nick_prefix(char) const;
+
+    Function<void()> on_connect;
+    Function<void()> on_disconnect;
+    Function<void(const String& channel)> on_channel_message;
+    Function<void(const String& name)> on_query_message;
+    Function<void()> on_server_message;
+
+private:
+    struct Message {
+        String prefix;
+        String command;
+        Vector<String> arguments;
+    };
+
+    void receive_from_server();
+    void send(const String&);
+    void send_user();
+    void send_nick();
+    void send_pong(const String& server);
+    void process_line();
+    void handle_join(const Message&);
+    void handle_ping(const Message&);
+    void handle_namreply(const Message&);
+    void handle_privmsg(const Message&);
+    void handle(const Message&);
+    IRCQuery& ensure_query(const String& name);
+
+    String m_hostname;
+    int m_port { 0 };
+    int m_socket_fd { -1 };
+
+    String m_nickname;
+    Vector<char> m_line_buffer;
+    OwnPtr<GNotifier> m_notifier;
+    HashMap<String, RetainPtr<IRCChannel>> m_channels;
+    HashMap<String, RetainPtr<IRCQuery>> m_queries;
+
+    CircularQueue<String, 1024> m_server_messages;
+};