Add a basic XMPP component implementation, doing the authentication

src/xmpp/xmpp_component.hpp

@@ -0,0 +1,80 @@
+#ifndef XMPP_COMPONENT_INCLUDED
+# define XMPP_COMPONENT_INCLUDED
+
+#include <string>
+
+#include <network/socket_handler.hpp>
+
+#include <xmpp/xmpp_parser.hpp>
+
+#include <unordered_map>
+
+/**
+ * An XMPP component, communicating with an XMPP server using the protocole
+ * described in XEP-0114: Jabber Component Protocol
+ *
+ * TODO: implement XEP-0225: Component Connections
+ */
+class XmppComponent: public SocketHandler
+{
+public:
+  explicit XmppComponent(const std::string& hostname, const std::string& secret);
+  ~XmppComponent();
+  void on_connected();
+  void on_connection_close();
+  void parse_in_buffer();
+
+  /**
+   * Connect to the XMPP server
+   */
+  void start();
+  /**
+   * Serialize the stanza and add it to the out_buf to be sent to the
+   * server.
+   */
+  void send_stanza(const Stanza& stanza);
+  /**
+   * Handle the opening of the remote stream
+   */
+  void on_remote_stream_open(const XmlNode& node);
+  /**
+   * Handle the closing of the remote stream
+   */
+  void on_remote_stream_close(const XmlNode& node);
+  /**
+   * Handle received stanzas
+   */
+  void on_stanza(const Stanza& stanza);
+  /**
+   * Send an error stanza. Message being the name of the element inside the
+   * stanza, and explanation being a short human-readable sentence
+   * describing the error.
+   */
+  void send_stream_error(const std::string& message, const std::string& explanation);
+  /**
+   * Send the closing signal for our document (not closing the connection though).
+   */
+  void close_document();
+
+  /**
+   * Handle the various stanza types
+   */
+  void handle_handshake(const Stanza& stanza);
+
+private:
+  XmppParser parser;
+  std::string stream_id;
+  std::string served_hostname;
+  std::string secret;
+  bool authenticated;
+
+  std::unordered_map<std::string, std::function<void(const Stanza&)>> stanza_handlers;
+
+  XmppComponent(const XmppComponent&) = delete;
+  XmppComponent(XmppComponent&&) = delete;
+  XmppComponent& operator=(const XmppComponent&) = delete;
+  XmppComponent& operator=(XmppComponent&&) = delete;
+};
+
+#endif // XMPP_COMPONENT_INCLUDED
+