Implement basic virtual Room support based on enet (#2803)

* Added support for network with ENet lib,

connecting is possible, but data can't be sent, yet.

* fixup! Added support for network with ENet lib,

* fixup! CLang

* fixup! Added support for network with ENet lib,

* fixup! Added support for network with ENet lib,

* fixup! Clang format

* More fixups!

* Moved ENetHost* and ENetPeer* into pimpl classes

* fixup! Moved ENetHost* and ENetPeer* into pimpl classes

* fixup! Clang again

* fixup! Moved ENetHost* and ENetPeer* into pimpl classes

* fixup! Moved ENetHost* and ENetPeer* into pimpl classes

* fixup! Moved ENetHost* and ENetPeer* into pimpl classes

1 files changed, 74 insertions, 0 deletions

diff --git a/src/network/room_member.cpp b/src/network/room_member.cpp
new file mode 100644
index 000000000..c87f009f4
--- /dev/null
+++ b/src/network/room_member.cpp
@@ -0,0 +1,74 @@
+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "common/assert.h"
+#include "enet/enet.h"
+#include "network/room_member.h"
+
+namespace Network {
+
+constexpr u32 ConnectionTimeoutMs = 5000;
+
+class RoomMember::RoomMemberImpl {
+public:
+    ENetHost* client = nullptr; ///< ENet network interface.
+    ENetPeer* server = nullptr; ///< The server peer the client is connected to
+
+    std::atomic<State> state{State::Idle}; ///< Current state of the RoomMember.
+
+    std::string nickname; ///< The nickname of this member.
+};
+
+RoomMember::RoomMember() : room_member_impl{std::make_unique<RoomMemberImpl>()} {
+    room_member_impl->client = enet_host_create(nullptr, 1, NumChannels, 0, 0);
+    ASSERT_MSG(room_member_impl->client != nullptr, "Could not create client");
+}
+
+RoomMember::~RoomMember() {
+    ASSERT_MSG(!IsConnected(), "RoomMember is being destroyed while connected");
+    enet_host_destroy(room_member_impl->client);
+}
+
+RoomMember::State RoomMember::GetState() const {
+    return room_member_impl->state;
+}
+
+void RoomMember::Join(const std::string& nick, const char* server_addr, u16 server_port,
+                      u16 client_port) {
+    ENetAddress address{};
+    enet_address_set_host(&address, server_addr);
+    address.port = server_port;
+
+    room_member_impl->server =
+        enet_host_connect(room_member_impl->client, &address, NumChannels, 0);
+
+    if (!room_member_impl->server) {
+        room_member_impl->state = State::Error;
+        return;
+    }
+
+    ENetEvent event{};
+    int net = enet_host_service(room_member_impl->client, &event, ConnectionTimeoutMs);
+    if (net > 0 && event.type == ENET_EVENT_TYPE_CONNECT) {
+        room_member_impl->nickname = nick;
+        room_member_impl->state = State::Joining;
+        // TODO(B3N30): Send a join request with the nickname to the server
+        // TODO(B3N30): Start the receive thread
+    } else {
+        room_member_impl->state = State::CouldNotConnect;
+    }
+}
+
+bool RoomMember::IsConnected() const {
+    return room_member_impl->state == State::Joining || room_member_impl->state == State::Joined;
+}
+
+void RoomMember::Leave() {
+    enet_peer_disconnect(room_member_impl->server, 0);
+    room_member_impl->state = State::Idle;
+    // TODO(B3N30): Close the receive thread
+    enet_peer_reset(room_member_impl->server);
+}
+
+} // namespace Network