#pragma once
#include <queue>
#include <mutex>
#include "../include/shared_types.h"

// Thread-safe queue of InputEvents. Written by the Win32 message pump thread,
// read by the Unity main thread via RRPOPOUT_PollInputEvents.
class InputQueue {
public:
    void push(const InputEvent& e) {
        std::lock_guard<std::mutex> lock(m_mutex);
        if (m_queue.size() < kMaxBacklog) {
            m_queue.push(e);
        }
    }

    // Drains up to maxEvents into outEvents. Returns number written.
    int drain(InputEvent* outEvents, int maxEvents) {
        std::lock_guard<std::mutex> lock(m_mutex);
        int n = 0;
        while (n < maxEvents && !m_queue.empty()) {
            outEvents[n++] = m_queue.front();
            m_queue.pop();
        }
        return n;
    }

private:
    static constexpr size_t kMaxBacklog = 256;
    std::queue<InputEvent> m_queue;
    std::mutex             m_mutex;
};