Implement the Bridge class to translate between the two protocols

Add all useful classes as well: Jid, Iid, IrcChannel, IrcUser etc to
properly keep the informations about what we receive from the IRC server.

Only handle the MUC join stanza, and send the list of users in the IRC
channel to the XMPP user, and the IRC channel’s topic, for now.

8 files changed, 318 insertions, 4 deletions

diff --git a/src/irc/iid.cpp b/src/irc/iid.cpp
new file mode 100644
index 0000000..ffc8d88
--- /dev/null
+++ b/src/irc/iid.cpp
@@ -0,0 +1,17 @@
+#include <irc/iid.hpp>
+
+Iid::Iid(const std::string& iid)
+{
+  std::string::size_type sep = iid.find("%");
+  if (sep != std::string::npos)
+    {
+      this->chan = iid.substr(0, sep);
+      sep++;
+    }
+  else
+    {
+      this->chan = iid;
+      return;
+    }
+  this->server = iid.substr(sep);
+}
diff --git a/src/irc/iid.hpp b/src/irc/iid.hpp
new file mode 100644
index 0000000..aacc9e6
--- /dev/null
+++ b/src/irc/iid.hpp
@@ -0,0 +1,34 @@
+#ifndef IID_INCLUDED
+# define IID_INCLUDED
+
+#include <string>
+
+/**
+ * A name representing an IRC channel, on the same model than the XMPP JIDs (but much simpler).
+ * The separator between the server and the channel name is '%'
+ * #test%irc.freenode.org has :
+ * - chan: "#test" (the # is part of the name, it could very well be absent, or & instead
+ * - server: "irc.freenode.org"
+ * #test has:
+ * - chan: "#test"
+ * - server: ""
+ * %irc.freenode.org:
+ * - chan: ""
+ * - server: "irc.freenode.org"
+ */
+class Iid
+{
+public:
+  explicit Iid(const std::string& iid);
+
+  std::string chan;
+  std::string server;
+
+private:
+  Iid(const Iid&) = delete;
+  Iid(Iid&&) = delete;
+  Iid& operator=(const Iid&) = delete;
+  Iid& operator=(Iid&&) = delete;
+};
+
+#endif // IID_INCLUDED
diff --git a/src/irc/irc_channel.cpp b/src/irc/irc_channel.cpp
new file mode 100644
index 0000000..223305b
--- /dev/null
+++ b/src/irc/irc_channel.cpp
@@ -0,0 +1,24 @@
+#include <irc/irc_channel.hpp>
+#include <utils/make_unique.hpp>
+
+IrcChannel::IrcChannel():
+  joined(false),
+  self(nullptr)
+{
+}
+
+void IrcChannel::set_self(const std::string& name)
+{
+  this->self = std::make_unique<IrcUser>(name);
+}
+
+IrcUser* IrcChannel::add_user(const std::string& name)
+{
+  this->users.emplace_back(std::make_unique<IrcUser>(name));
+  return this->users.back().get();
+}
+
+IrcUser* IrcChannel::get_self() const
+{
+  return this->self.get();
+}
diff --git a/src/irc/irc_channel.hpp b/src/irc/irc_channel.hpp
new file mode 100644
index 0000000..da0f298
--- /dev/null
+++ b/src/irc/irc_channel.hpp
@@ -0,0 +1,34 @@
+#ifndef IRC_CHANNEL_INCLUDED
+# define IRC_CHANNEL_INCLUDED
+
+#include <irc/irc_user.hpp>
+#include <memory>
+#include <string>
+#include <vector>
+
+/**
+ * Keep the state of a joined channel (the list of occupants with their
+ * informations (mode, etc), the modes, etc)
+ */
+class IrcChannel
+{
+public:
+  explicit IrcChannel();
+
+  bool joined;
+  std::string topic;
+  void set_self(const std::string& name);
+  IrcUser* get_self() const;
+  IrcUser* add_user(const std::string& name);
+
+private:
+  std::unique_ptr<IrcUser> self;
+  std::vector<std::unique_ptr<IrcUser>> users;
+
+  IrcChannel(const IrcChannel&) = delete;
+  IrcChannel(IrcChannel&&) = delete;
+  IrcChannel& operator=(const IrcChannel&) = delete;
+  IrcChannel& operator=(IrcChannel&&) = delete;
+};
+
+#endif // IRC_CHANNEL_INCLUDED
diff --git a/src/irc/irc_client.cpp b/src/irc/irc_client.cpp
index 80f36ee..7875b1c 100644
--- a/src/irc/irc_client.cpp
+++ b/src/irc/irc_client.cpp
@@ -1,10 +1,18 @@
-#include <irc/irc_client.hpp>
 #include <irc/irc_message.hpp>
+#include <irc/irc_client.hpp>
+#include <bridge/bridge.hpp>
+#include <irc/irc_user.hpp>
+
+#include <utils/make_unique.hpp>
+#include <utils/split.hpp>
 
 #include <iostream>
 #include <stdexcept>
 
-IrcClient::IrcClient()
+IrcClient::IrcClient(const std::string& hostname, const std::string& username, Bridge* bridge):
+  hostname(hostname),
+  username(username),
+  bridge(bridge)
 {
   std::cout << "IrcClient()" << std::endl;
 }
@@ -14,8 +22,15 @@ IrcClient::~IrcClient()
   std::cout << "~IrcClient()" << std::endl;
 }
 
+void IrcClient::start()
+{
+  this->connect(this->hostname, "6667");
+}
+
 void IrcClient::on_connected()
 {
+  this->send_nick_command(this->username);
+  this->send_user_command(this->username, this->username);
 }
 
 void IrcClient::on_connection_close()
@@ -23,6 +38,19 @@ void IrcClient::on_connection_close()
   std::cout << "Connection closed by remote server." << std::endl;
 }
 
+IrcChannel* IrcClient::get_channel(const std::string& name)
+{
+  try
+    {
+      return this->channels.at(name).get();
+    }
+  catch (const std::out_of_range& exception)
+    {
+      this->channels.emplace(name, std::make_unique<IrcChannel>());
+      return this->channels.at(name).get();
+    }
+}
+
 void IrcClient::parse_in_buffer()
 {
   while (true)
@@ -33,6 +61,21 @@ void IrcClient::parse_in_buffer()
       IrcMessage message(this->in_buf.substr(0, pos));
       this->in_buf = this->in_buf.substr(pos + 2, std::string::npos);
       std::cout << message << std::endl;
+      // TODO map function and command name properly
+      if (message.command == "PING")
+        this->send_pong_command();
+      else if (message.command == "NOTICE" ||
+               message.command == "375" ||
+               message.command == "372")
+        this->forward_server_message(message);
+      else if (message.command == "JOIN")
+        this->on_self_channel_join(message);
+      else if (message.command == "353")
+        this->set_and_forward_user_list(message);
+      else if (message.command == "332")
+        this->on_topic_received(message);
+      else if (message.command == "366")
+        this->on_channel_completely_joined(message);
     }
 }
 
@@ -52,6 +95,8 @@ void IrcClient::send_message(IrcMessage&& message)
       res += " " + arg;
     }
   res += "\r\n";
+  std::cout << "=== IRC SENDING ===" << std::endl;
+  std::cout << res << std::endl;
   this->send_data(std::move(res));
 }
 
@@ -67,5 +112,59 @@ void IrcClient::send_nick_command(const std::string& nick)
 
 void IrcClient::send_join_command(const std::string& chan_name)
 {
-  this->send_message(IrcMessage("JOIN", {chan_name}));
+  IrcChannel* channel = this->get_channel(chan_name);
+  if (channel->joined == false)
+    this->send_message(IrcMessage("JOIN", {chan_name}));
+}
+
+void IrcClient::send_pong_command()
+{
+  this->send_message(IrcMessage("PONG", {}));
+}
+
+void IrcClient::forward_server_message(const IrcMessage& message)
+{
+  const std::string from = message.prefix;
+  const std::string body = message.arguments[1];
+
+  this->bridge->send_xmpp_message(this->hostname, from, body);
+}
+
+void IrcClient::set_and_forward_user_list(const IrcMessage& message)
+{
+  const std::string chan_name = message.arguments[2];
+  IrcChannel* channel = this->get_channel(chan_name);
+  std::vector<std::string> nicks = utils::split(message.arguments[3], ' ');
+  for (const std::string& nick: nicks)
+    {
+      IrcUser* user = channel->add_user(nick);
+      if (user->nick != channel->get_self()->nick)
+        {
+          std::cout << "Adding user [" << nick << "] to chan " << chan_name << std::endl;
+          this->bridge->send_user_join(this->hostname, chan_name, user->nick);
+        }
+    }
+}
+
+void IrcClient::on_self_channel_join(const IrcMessage& message)
+{
+  const std::string chan_name = message.arguments[0];
+  IrcChannel* channel = this->get_channel(chan_name);
+  channel->joined = true;
+  channel->set_self(message.prefix);
+}
+
+void IrcClient::on_topic_received(const IrcMessage& message)
+{
+  const std::string chan_name = message.arguments[1];
+  IrcChannel* channel = this->get_channel(chan_name);
+  channel->topic = message.arguments[2];
+}
+
+void IrcClient::on_channel_completely_joined(const IrcMessage& message)
+{
+  const std::string chan_name = message.arguments[1];
+  IrcChannel* channel = this->get_channel(chan_name);
+  this->bridge->send_self_join(this->hostname, chan_name, channel->get_self()->nick);
+  this->bridge->send_topic(this->hostname, chan_name, channel->topic);
 }
diff --git a/src/irc/irc_client.hpp b/src/irc/irc_client.hpp
index e380f5b..db1b83b 100644
--- a/src/irc/irc_client.hpp
+++ b/src/irc/irc_client.hpp
@@ -2,11 +2,16 @@
 # define IRC_CLIENT_INCLUDED
 
 #include <irc/irc_message.hpp>
+#include <irc/irc_channel.hpp>
+#include <irc/iid.hpp>
 
 #include <network/socket_handler.hpp>
 
+#include <unordered_map>
 #include <string>
 
+class Bridge;
+
 /**
  * Represent one IRC client, i.e. an endpoint connected to a single IRC
  * server, through a TCP socket, receiving and sending commands to it.
@@ -16,9 +21,13 @@
 class IrcClient: public SocketHandler
 {
 public:
-  explicit IrcClient();
+  explicit IrcClient(const std::string& hostname, const std::string& username, Bridge* bridge);
   ~IrcClient();
   /**
+   * Connect to the IRC server
+   */
+  void start();
+  /**
    * Called when successfully connected to the server
    */
   void on_connected();
@@ -32,12 +41,20 @@ public:
    */
   void parse_in_buffer();
   /**
+   * Return the channel with this name, create it if it does not yet exist
+   */
+  IrcChannel* get_channel(const std::string& name);
+  /**
    * Serialize the given message into a line, and send that into the socket
    * (actually, into our out_buf and signal the poller that we want to wach
    * for send events to be ready)
    */
   void send_message(IrcMessage&& message);
   /**
+   * Send the PONG irc command
+   */
+  void send_pong_command();
+  /**
    * Send the USER irc command
    */
   void send_user_command(const std::string& username, const std::string& realname);
@@ -49,8 +66,49 @@ public:
    * Send the JOIN irc command
    */
   void send_join_command(const std::string& chan_name);
+  /**
+   * Forward the server message received from IRC to the XMPP component
+   */
+  void forward_server_message(const IrcMessage& message);
+  /**
+   * Forward the join of an other user into an IRC channel, and save the
+   * IrcUsers in the IrcChannel
+   */
+  void set_and_forward_user_list(const IrcMessage& message);
+  /**
+   * Remember our nick and host, when we are joined to the channel. The list
+   * of user comes after so we do not send the self-presence over XMPP yet.
+   */
+  void on_self_channel_join(const IrcMessage& message);
+  /**
+   * Save the topic in the IrcChannel
+   */
+  void on_topic_received(const IrcMessage& message);
+  /**
+   * The channel has been completely joined (self presence, topic, all names
+   * received etc), send the self presence and topic to the XMPP user.
+   */
+  void on_channel_completely_joined(const IrcMessage& message);
 
 private:
+  /**
+   * The hostname of the server we are connected to.
+   */
+  const std::string hostname;
+  /**
+   * The user name used in the USER irc command
+   */
+  const std::string username;
+  /**
+   * Raw pointer because the bridge owns us.
+   */
+  Bridge* bridge;
+
+  /**
+   * The list of joined channels, indexed by name
+   */
+  std::unordered_map<std::string, std::unique_ptr<IrcChannel>> channels;
+
   IrcClient(const IrcClient&) = delete;
   IrcClient(IrcClient&&) = delete;
   IrcClient& operator=(const IrcClient&) = delete;
diff --git a/src/irc/irc_user.cpp b/src/irc/irc_user.cpp
new file mode 100644
index 0000000..fc853bc
--- /dev/null
+++ b/src/irc/irc_user.cpp
@@ -0,0 +1,24 @@
+#include <irc/irc_user.hpp>
+
+#include <iostream>
+
+IrcUser::IrcUser(const std::string& name)
+{
+  const std::string::size_type sep = name.find("!");
+  if (sep == std::string::npos)
+    {
+      if (name[0] == '@' || name[0] == '+')
+        this->nick = name.substr(1);
+      else
+        this->nick = name;
+    }
+  else
+    {
+      if (name[0] == '@' || name[0] == '+')
+        this->nick = name.substr(1, sep);
+      else
+        this->nick = name.substr(0, sep);
+      this->host = name.substr(sep+1);
+    }
+  std::cout << "Created user: [" << this->nick << "!" << this->host << std::endl;
+}
diff --git a/src/irc/irc_user.hpp b/src/irc/irc_user.hpp
new file mode 100644
index 0000000..b76b2ef
--- /dev/null
+++ b/src/irc/irc_user.hpp
@@ -0,0 +1,24 @@
+#ifndef IRC_USER_INCLUDED
+# define IRC_USER_INCLUDED
+
+#include <string>
+
+/**
+ * Keeps various information about one IRC channel user
+ */
+class IrcUser
+{
+public:
+  explicit IrcUser(const std::string& name);
+
+  std::string nick;
+  std::string host;
+
+private:
+  IrcUser(const IrcUser&) = delete;
+  IrcUser(IrcUser&&) = delete;
+  IrcUser& operator=(const IrcUser&) = delete;
+  IrcUser& operator=(IrcUser&&) = delete;
+};
+
+#endif // IRC_USER_INCLUDED