#pragma once
#include <hidapi.h>
#include <cstdint>
#include <string>
#include <thread>
#include <atomic>
#include <mutex>
#include "user_signature.h"
#include "proximity_algorithm.h"

class HidDevice
{
public:
    explicit HidDevice(int avgLength = 8, bool logVerbose = false);
    ~HidDevice();

    // Non-copyable, non-movable
    HidDevice(const HidDevice&) = delete;
    HidDevice& operator=(const HidDevice&) = delete;

    // Returns true if device was opened successfully
    bool Open(uint16_t vid, uint16_t pid);

    // Close the device (also called by destructor)
    void Close();

    // Query state
    bool IsOpen() const;

    // --- Reader thread API ---

    // Launch background reader thread that handles open/read/reconnect internally
    void StartReading(uint16_t vid, uint16_t pid, uint16_t rateMs = 200);

    // Stop the reader thread and close device
    void StopReading();

    // Lock-free cached proximity distance from latest '#' periodic report
    uint16_t GetProxDistance() const;

    // Connection state: 0=closed, 1=open, 2=reconnecting
    int GetConnectionState() const;

    // Thread-safe copy of calibration data read from user signature flash
    CalibrationData GetCalibration() const;

    // Thread-safe copy of lighthouse tracking serial from user flash (tag 0x09)
    std::string GetTrackingSerial() const;

    // Proximity algorithm results (lock-free, safe from any thread)
    bool GetPersonDetected() const;
    ProximityAlgorithm::DiagState GetAlgorithmDiag() const;

private:
    hid_device* m_pDevice;

    // Reader thread state
    std::thread m_readerThread;
    std::atomic<bool> m_bStopRequested{false};
    std::atomic<uint16_t> m_lastProxDistance{0};
    std::atomic<int> m_connectionState{0};  // 0=closed, 1=open, 2=reconnecting

    // Calibration data (protected by mutex -- not atomic-safe)
    CalibrationData m_calibration;
    mutable std::mutex m_calMutex;

    // Verbose logging flag
    bool m_logVerbose = false;

    // Proximity algorithm (owned, fed from reader thread)
    ProximityAlgorithm m_proximityAlgorithm;

    // Reader thread entry point
    void ReaderThreadFunc(uint16_t vid, uint16_t pid, uint16_t rateMs);

    // HID communication helpers
    bool SendFeatureReport(uint8_t cmdCode, const uint8_t* data, size_t dataLen);
    int ReadReport(uint8_t* buf, size_t bufLen, int timeoutMs);
    bool SetReportRate(uint16_t rateMs);
    bool ReadUserSignature(uint8_t* sigOut, size_t sigLen);
    void ReadCalibration();
};