// NTP headers
#include <NTPClient.h>
#include <WiFiUdp.h>
#include <NTPClient.h>

template <typename SessionT>
class SessionManager
{
public:
    SessionManager(int scaleDoutPin, int scaleSckPin, uint8_t tareAvgCount);

    void begin();

    void tare();
    long tareOffset() const { return scale_.offset(); };
    void startMeasurements();
    void stopMeasurements();
    bool isMeasuring() const { return measuring_; }
    SessionT &session() { return session_; }

    void iteration();

private:
    WiFiUDP ntpUDP_;
    NTPClient timeClient_;

    Scale<CONFIG_VALUE_DIVIDER> scale_;
    //MockScale scale;
    SessionT session_;
    bool measuring_;
    long lastCallTime_;

    int scaleDoutPin_;
    int scaleSckPin_;
    uint8_t tareAvgCount_;
};

// ------------------------------------------------------------------------------------------------

template <typename SessionT>
SessionManager<SessionT>::SessionManager(int scaleDoutPin, int scaleSckPin, uint8_t tareAvgCount)
    : timeClient_(ntpUDP_, "pool.ntp.org"),
      measuring_(false),
      lastCallTime_(0),
      scaleDoutPin_(scaleDoutPin),
      scaleSckPin_(scaleSckPin),
      tareAvgCount_(tareAvgCount)
{
}

template <typename SessionT>
void SessionManager<SessionT>::tare()
{
    if(measuring_)
        stopMeasurements();
    Serial.println("Beginning tare");
    scale_.begin(scaleDoutPin_, scaleSckPin_);
    scale_.tare(CONFIG_TARE_AVG_COUNT);
    Serial.println("Finished tare");
}

template <typename SessionT>
void SessionManager<SessionT>::begin()
{
    timeClient_.begin();
    timeClient_.update();
    tare();
    session_.init(timeClient_.getEpochTime());
}

template <typename SessionT>
void SessionManager<SessionT>::startMeasurements()
{
    if(measuring_ == true)
        return;
    measuring_ = true;
    lastCallTime_ = 0;
    session_.init(timeClient_.getEpochTime());
}

template <typename SessionT>
void SessionManager<SessionT>::stopMeasurements()
{
    if(measuring_ == false)
        return;
    session_.finalize();
    measuring_ = false;
}

template <typename SessionT>
void SessionManager<SessionT>::iteration()
{
    if (!measuring_)
        return;

    uint16_t measurement = -1;
    bool measurementDone = false;
    while(!measurementDone)
        measurementDone = scale_.measure(measurement);
    bool addPointSuccessful = session_.addPoint(measurement);
    Serial.printf("Measured: %d\n", measurement);
    if (!addPointSuccessful)
    {
        Serial.println("Maximum time of session reached - stopping");
        stopMeasurements();
        return;
    }
    if (lastCallTime_ != 0)
    {
        const long cycleDuration = millis() - lastCallTime_;
        if (cycleDuration <= CONFIG_MEASURE_DELAY)
        {
            delay(CONFIG_MEASURE_DELAY - cycleDuration);
        }
        else
        {
            const long skipped = (cycleDuration / CONFIG_MEASURE_DELAY);
            Serial.printf("Warning: measurements skipped: %ld, cycleDuration %ld", skipped, cycleDuration);

            for (int i = 0; i < skipped; ++i)
                session_.addPoint(measurement);

            delay(CONFIG_MEASURE_DELAY * (skipped + 1) - cycleDuration);
        }
    }
    lastCallTime_ = millis();
}