#ifndef NET_CLASS
#define NET_CLASS

#include <cstdint>
#include <string>
#include <vector>
#include <glm/glm.hpp>
#include <glm/gtc/quaternion.hpp>

// Multiplayer UDP link for a LAN pit. One player hosts (UDP port 27015), everyone else joins by IP.
// Clients send their own transform to the host every frame; the host relays everyone's
// transform to everyone else. The host is player id 0, joiners get ids 1, 2, 3, ...
// All Winsock code lives in Net.cpp so windows.h never leaks into the rest of the engine.

struct NetState {
    glm::vec3 position = glm::vec3(0.0f);
    glm::quat rotation = glm::quat(1.0f, 0.0f, 0.0f, 0.0f);
    bool      sliding = false;
};

// A state received for some other player.
struct NetUpdate {
    uint8_t  id = 0;
    NetState state;
};

class Lan {
public:
    enum class Mode { Off, Host, Client };

    // Total players in the pit, host included.
    static constexpr int MaxPlayers = 8;

    Lan();
    ~Lan();

    // Opens the socket. For Client, hostIp is the host's IPv4 address. Returns false on failure.
    bool Start(Mode mode, const std::string& hostIp);
    void Stop();

    Mode GetMode() const { return mode; }
    bool IsActive() const { return active; }

    // Call once per frame with our own state.
    void Send(const NetState& state);
    // Drains all waiting packets and appends the other players' newest states to 'out'.
    void Receive(std::vector<NetUpdate>& out);

    // Host: at least one player has joined. Client: the host has been heard from in the last 2 s.
    bool IsConnected() const;
    // Host only: number of joined players, not counting the host.
    int PeerCount() const;

    // This machine's IPv4 addresses (for the host to read out to the joiners).
    static std::string LocalAddresses();

private:
    struct Impl;
    Impl* impl;
    Mode mode = Mode::Off;
    bool active = false;
};

inline Lan* lan = nullptr;

#endif