#pragma once

#include <cstdint>
#include <cstddef>

// CRC8 with polynomial 0x07, initial value 0xFF
// Used for validating TLV entries in the user signature page
uint8_t Crc8(const uint8_t* data, size_t len);

// Tag IDs for user signature TLV entries (subset relevant to proximity)
enum class SigTag : uint8_t
{
    Invalid         = 0xFF,
    ProxCal         = 0x06,
    HmdSerial       = 0x08,    // HMD serial for BS1/BS2 detection
    TrackingSerial  = 0x09,
    ProxThreshold   = 0x0B,
    ProxHysteresis  = 0x0C,
    UserProxTrim    = 0x0E,
};

// Calibration parameters extracted from user signature flash
struct CalibrationData
{
    uint16_t programmed_cal = 0;
    uint16_t proximity_threshold = 1500;   // firmware default: PROX_SENSOR_THRESHOLD
    uint16_t proximity_hysteresis = 100;   // firmware default: PROX_SENSOR_HYSTERESIS
    int16_t  user_trim = 0;               // SIGNED -- firmware explicitly notes this
    char tracking_serial[32] = {};        // lighthouse serial from tag 0x09 (e.g. "LHR-XXXXXXXX")
    char hmd_serial[32] = {};             // HMD serial from tag 0x08 (e.g. "BS2-XXXXXXXX")
};

// Parse calibration data from a 512-byte user signature page (TLV + CRC8 format)
// Returns CalibrationData with defaults for any tags not found or with bad CRC
CalibrationData ParseCalibration(const uint8_t* sig, size_t sigLen);