connect and heartbeat

1 files changed, 75 insertions, 0 deletions

diff --git a/discord/discord.hpp b/discord/discord.hpp
new file mode 100644
index 0000000..692d57b
--- /dev/null
+++ b/discord/discord.hpp
@@ -0,0 +1,75 @@
+#pragma once
+#include "websocket.hpp"
+#include <nlohmann/json.hpp>
+#include <thread>
+
+enum class GatewayOp : int {
+    Heartbeat = 1,
+    Hello = 10,
+    HeartbeatAck = 11,
+};
+
+struct GatewayMessage {
+    GatewayOp Opcode;
+    nlohmann::json Data;
+    std::string Type;
+
+    friend void from_json(const nlohmann::json &j, GatewayMessage &m);
+};
+
+struct HelloMessageData {
+    int HeartbeatInterval;
+
+    friend void from_json(const nlohmann::json &j, HelloMessageData &m);
+};
+
+struct HeartbeatMessage : GatewayMessage {
+    int Sequence;
+
+    friend void to_json(nlohmann::json &j, const HeartbeatMessage &m);
+};
+
+// https://stackoverflow.com/questions/29775153/stopping-long-sleep-threads/29775639#29775639
+class HeartbeatWaiter {
+public:
+    template<class R, class P>
+    bool wait_for(std::chrono::duration<R, P> const &time) const {
+        std::unique_lock<std::mutex> lock(m);
+        return !cv.wait_for(lock, time, [&] { return terminate; });
+    }
+    void kill() {
+        std::unique_lock<std::mutex> lock(m);
+        terminate = true;
+        cv.notify_all();
+    }
+
+private:
+    mutable std::condition_variable cv;
+    mutable std::mutex m;
+    bool terminate = false;
+};
+
+class DiscordClient {
+public:
+    static const constexpr char *DiscordGateway = "wss://gateway.discord.gg/?v=6&encoding=json";
+    static const constexpr char *DiscordAPI = "https://discord.com/api";
+
+public:
+    DiscordClient();
+    void Start();
+    void Stop();
+    bool IsStarted() const;
+
+private:
+    void HandleGatewayMessage(nlohmann::json msg);
+    void HeartbeatThread();
+
+    Websocket m_websocket;
+    bool m_client_connected = false;
+
+    std::thread m_heartbeat_thread;
+    int m_last_sequence = -1;
+    int m_heartbeat_msec = 0;
+    HeartbeatWaiter m_heartbeat_waiter;
+    bool m_heartbeat_acked = true;
+};